The Great Step Backwards: Polymer to Monomer

By Hyungjun Cho, member-at-large for the GCI

There is a movement to develop a new type of product life system called ‘the circular economy’ [3]. Part of this movement aims to manufacture products from recycled or raw materials, and after its useful lifetime, re-introduce the product (now considered waste) as recycled material. The motivation for the introduction of the circular economy is to minimize the need for virgin raw material, especially when it originates from non-renewable resources. This effort is being spearheaded by the Ellen MacArthur Foundation with major industry partners like Google, Unilever, Solvay, and Philips, among others [3]. A critical component to the function of the circular economy is developing the capability to turn waste into a desirable product.

There are several methods of recycling all the different types of materials we use in every day life. This blog will discuss a niche in the ‘plastic to monomer’ field. Evidently, in April of 2019, IUPAC named ‘plastic to monomer’ as part of the 10 chemical innovations that could have high impact in society [6]. Before discussing ‘plastic to monomer’, I must clarify the term ‘plastic’. Generally, plastic is made up of many polymer chains that are physically entangled with one another. A macroscopic analogy is when many electrical wires (think of Christmas tree lights) become entangled: the wires are stuck to each other and the rigidity of the ball of wire is greater than the rigidity of a single wire.

Much like the type of wire influences the tangled ball it forms, the chemical structure of the polymer influences the material properties of the plastic. Examples of properties of plastics include rigidity, elasticity, malleability, gas permeability, friction to skin, transparency, and many others. The polymers that are used for commercial plastic products have been studied and developed for decades to be able perform a specific function. For example, polyvinyl chloride and polystyrene were initially discovered in the 1800s [2,8]. Thus, it would be ideal if the currently used polymers can be de-polymerized back into monomers for recycling purposes. This would be a major move by the plastics industry to become environmentally friendly.

The conventional method to turn polymers into monomer is thermal decomposition. Samples of polymer can be heated to high temperature (typically 220-500 °C) to break some of the bonds that hold the monomers together [10]. When this occurs, radicals can form at the site of the broken bond, which can lead to de-polymerization [10]. The required temperature and how much monomer is formed is dependent on the chemical structure of the monomers that are formed. Thermal decomposition to recover monomer is suitable only for a few types of polymers, such as poly(α-methylstyrene), which has ceiling temperature of 66 °C to propagate depolymerization; the monomer recovery after thermal decomposition of poly(α-methylstyrene) is excellent at 95% [11]. However, for polymers like polyethylene (PE, the most produced polymer) and polypropylene (PP, 2nd most produced polymer), the monomer recovery yield is poor (0.025-2%) [11]. In some cases such as polyvinylchloride (PVC, 3rd most produced polymer), thermal decomposition is even more problematic because PVC will release harmful hydrochloric acid and vinylenes upon heating [11]. Thus, the monomer recovery is poor (1 %) and the process is highly corrosive.

Therefore, one of the key challenges to address for ‘polymer to monomer’ is to perform de-polymerization at a low temperature. There are 4 recent publications that explore this challenge [5,7,9,12]. In general, the authors synthesized polymers using reversible-deactivation radical polymerization (RDRP) techniques and explored the de-polymerization reactions they encountered. Below is a brief highlight from the publications from the Haddleton group [9] and the Gramlich group [5].

Picture1

Scheme 1: De-polymerization of RAFT polymers with trithioester end-group [5]. Reproduced from ref. [5] with permission from The Royal Society of Chemistry.

Flanders et al. polymerized methacrylate monomers, including methylmethacrylate (MMA), using reversible addition-fragmentation chain-transfer (RAFT) polymerization with a trithioester chain-transfer agent (CTA) [5]. This type of polymerization places trithioester end-group at end of the polymer chain (Scheme 1). Typically, this end-group is used to re-start the polymerization at the trithioester end of the polymer. However, as we will see, it may have another function. The authors isolated the polymer, then re-dissolved the polymer in 1,4-dioxane at 70 °C (Scheme 1). This caused monomers to be released from the polymer chains at a temperature much less than the ceiling temperature of MMA, which is 227 °C [13]. Analysis of the polymer after partial de-polymerization demonstrated that the trithioester end-group was still attached to the polymer and the size dispersity (range of polymer ‘molecular weight’) was low, which suggested that the de-polymerization was moderated by the trithioester end-group. The authors observed 10-35% de-polymerization after heating at 70 °C for 12-60 hrs.

Picture2

Scheme 2: ATRP of NIPAM in carbonated water, followed by de-polymerization [9]. Reproduced from ref. [9] with permission from The Royal Society of Chemistry.

Lloyd et al. used an alkylbromide initiator, Cu-based catalyst system to polymerize N-isopropylacrylamide (NIPAM) in Highland Spring carbonated water at 0 °C (Scheme 2) [9]. This type of polymerization places a halide at the end of the polymer chain. The authors monitored the monomer conversion into polymer using 1H-NMR spectroscopy. They measured that ca. 99% of the monomer was converted into polymer chains within 10 min. Unexpectedly, in the next 50 min. the authors observed 50% de-polymerization. The authors attempted to optimize de-polymerization conditions by changing the pH, using dry ice in HPLC grade water instead of Highland Spring carbonated water, etc. which led to 34-71% de-polymerization after 0.5-24 hrs. Years later, the same group used a very similar polymerization condition to polymerize NIPAM [1]. This time, non-carbonated water was used as the solvent and they did not report any de-polymerization.

The reports on RDRP followed by de-polymerization highlighted here are not yet ready to make an impact to ‘plastic to monomer’. The authors admit that the mechanism of de-polymerization is unknown. However, these seem to be the first set of reports on de-polymerization occurring at low temperatures. Perhaps these publications could be the birth of the reversible-deactivation radical de-polymerization (RDRDe-P) field. This is especially intriguing because RDRP have already been studied for decades in academia and are being adopted by the polymer industry [4]. Companies like BASF, Solvay, DuPont, L’Oréal, Unilever, 3 M, Arkema, PPG Industries, etc. already claimed patents for technology and products based on RDRP [4]. Somewhat ironically, RDRP was also part of the IUPAC’s 10 chemical innovations for impact on society but not for its potential to recycle polymer [6].

The polymers of the future may not be made from monomers abundantly used today, but the polymers of the future may be degradable through a low energy process.

References

  1.  Alsubaie, F.; Liarou, E.; Nikolaou, V.; Wilson, P.; Haddleton, D. M. Thermoresponsive Viscosity of Polyacrylamide Block Copolymers Synthesised via Aqueous Cu-RDRP. European Polymer Journal 2019, 114, 326–331.
  2. Baumann, E. Ueber Einige Vinylverbindungen. Justus Liebigs Annalen der Chemie 1872, 163 (3), 308–322.
  3. Circular Economy – UK, USA, Europe, Asia & South America – The Ellen MacArthur Foundation https://www.ellenmacarthurfoundation.org/ (accessed Jan 5, 2020).
  4. Destarac, M. Industrial Development of Reversible-Deactivation Radical Polymerization: Is the Induction Period Over? Chem. 2018, 9 (40), 4947–4967.
  5. Flanders, M. J.; Gramlich, W. M. Reversible-Addition Fragmentation Chain Transfer (RAFT) Mediated Depolymerization of Brush Polymers. Chem. 2018, 9 (17), 2328–2335.
  6. Gomollón-Bel, F. Ten Chemical Innovations That Will Change Our World: IUPAC Identifies Emerging Technologies in Chemistry with Potential to Make Our Planet More Sustainable. Chemistry International 2019, 41 (2), 12–17.
  7. Li, L.; Shu, X.; Zhu, J. Low Temperature Depolymerization from a Copper-Based Aqueous Vinyl Polymerization System. Polymer 2012, 53 (22), 5010–5015.
  8. Liebig, J. Justus Liebig’s Annalen Der Chemie. Annalen der Chemie 1832, 1874-1978.
  9. Lloyd, D. J.; Nikolaou, V.; Collins, J.; Waldron, C.; Anastasaki, A.; Bassett, S. P.; Howdle, S. M.; Blanazs, A.; Wilson, P.; Kempe, K.; et al. Controlled Aqueous Polymerization of Acrylamides and Acrylates and “in Situ” Depolymerization in the Presence of Dissolved CO2. Commun. 2016, 52 (39), 6533–6536.
  10. Microwave-Assisted Polymer Synthesis. Springer eBooks 2016
  11. Moldoveanu, Șerban. Analytical Pyrolysis of Synthetic Organic Polymers; Techniques and instrumentation in analytical chemistry; Elsevier: Amsterdam ; Oxford, 2005.
  12. Sano, Y.; Konishi, T.; Sawamoto, M.; Ouchi, M. Controlled Radical Depolymerization of Chlorine-Capped PMMA via Reversible Activation of the Terminal Group by Ruthenium Catalyst. European Polymer Journal 2019, 120, 109181.
  13. SFPE Handbook of Fire Protection Engineering, 5th ed.; Hurley, M. J., Gottuk, D. T., Jr, J. R. H., Harada, K., Kuligowski, E. D., Puchovsky, M., Torero, J. L., Jr, J. M. W., Wieczorek, C. J., Eds.; Springer-Verlag: New York, 2016.

Green Marketing in the Plastic Era: Honesty or Hype?

By Nina-Francesca Farac, Member-at-Large for the GCI

The impact of human activity on climate and the environment has moved beyond a mainstream headline. It has come to the point where we are considered the dominant influence on our ecosystems and geology, so much so that there is a buzzword for it: ‘Anthropocene’. Within the Anthropocene, our greatest challenge is lessening the effects of our immense footprint on Earth, mainly caused by consumption of fossil fuels and our obsession with plastics. Consequently, there has been a considerable spike in eco-friendly or ‘green’ marketing of numerous products labeled as ‘organic’, ‘biodegradable’, or ‘sustainable’ ranging from fuels, cars, skincare, all the way to clothing1. One common advertising theme for several everyday products is post-consumer recycled materials and their incorporation into the design and production of such commodities.  But to what extent are the advertised claims legitimate and whether they allow for a circular economy (e.g. make, use, recover)? Here, we will cover the chemistry of popular sustainable alternatives to plastics and compare them to their non-sustainable counterparts to assess whether the ‘green’ hype is valid.

Recycling Plastics: Single-Use vs. Biodegradable vs. Compostable

Let’s start with why commonly used plastics, including single-use plastics, pose such an environmental liability. The reality of plastic recycling is that it is far less efficient in practice than one would hope. The types of plastics that can be recycled, the number of times they can be recycled and reused starts with the ubiquitous recycling symbols found on the bottom of plastic products2. A common misconception is to equate the presence of this symbol to the ability of recycling a given type of plastic; however, this is not the case. The truth is just because there is a recycling sign doesn’t necessarily mean it gets recycled3. According to Resin Identification Codes (RICs), plastics are organized into 7 categories according to the temperature at which the material has been heated, and this numerical categorization is only indicative of the kind of plastic it is, and not necessarily its recyclability (Fig. 1).

Image 1

Figure 1. Resin Identification Codes (RICs) designating the seven categories of plastics, the corresponding chemical structure of each polymer, and graphical illustrations of common plastic products of each type.

In other words, just because we place it in a blue bin doesn’t mean it gets recycled. In fact, an astonishing 91% of plastics are not recycled2. You may be wondering, “how are recycling rates that low?” As with any commodity, recycling is ultimately determined by the market.  If there is a demand, recyclers and companies will pay for post-consumer recyclables; but, without market demand, recycling bares no profit and placing them in a blue bin doesn’t make a difference3. For example, out of the seven categories of plastics depicted in Figure 1, only PET has a high recycling value (i.e. the price of PET scrap is high) while other plastics are projected to see a drop in recycling rates (at least in North America)4–6. In addition, certain types of everyday plastics are simply not recyclable, such as plastic bags, straws, and coffee cups (the latter is not possible unless the paper exterior is separated from the plastic interior)3; in effect, these items are tossed together in the “everything else” category #7 (Other) as non-recyclables and mainly contribute to plastic waste generation. Other limiting factors include the inability to recycle dirty plastic and how the quality of plastic is downgraded each time plastic is recycled7.

Since many everyday items are plastic-based and plastics are a staple of modern life, the most common sustainable alternative to single-use plastics are bioplastics, a.ka biodegradable plastics (Figure 2).

Image 2

Figure 2. Types of biodegradable plastics in use today, their chemical structures, and their applications.

Consumer confusion often arises when the terms “biodegradable” and “compostable” are used interchangeably, although they do not convey the same concept. Biodegradable plastics are a class of polymers that can break down by the action of living organisms into natural byproducts such as water, biomass, gases (e.g. N2, CO2, H2, CH4), and inorganic salts within a reasonable amount of time8. The issue with this definition is that many plastic products eventually degrade; for instance, low density polyethylene (LDPE, category #4 – Fig. 1) has been shown to biodegrade slowly to carbon dioxide (0.35% in 2.5 years) and thus can be considered a biodegradable polymer according to the above description9. Because certain definitions of biodegradability do not state a time limit or timeframe within which degradation should occur, consumers can be easily misled, and companies can hide behind this ambiguity. It is assumed, however, that a biodegradable product has a degradation rate that is comparable to that of its application rate, i.e. the break down process is fast such that product accumulation in the environment does not occur.

To understand why certain polymers biodegrade and others do not, one has to consider the chemical structure of biodegradable polymers along with the mechanisms through which polymeric material are biodegraded. Structurally, many biodegradable polymers, both natural and synthetic, often contain amide, ester, or ether bonds10. Those deriving from biomass (i.e. agro-polymers) include polysaccharides (glycosidic bonds via condensation of a saccharide hemiacetal bond and an alcohol) and proteins (chains of amino acids linked via amide groups). The other major category is biopolyesters, which are typically derived from microorganisms or are synthetically made (Figure 3).

Image 3

Figure 3. Categories of biodegradable polymers.

Mechanistically, biodegradation is defined as a process caused by biological activity, especially driven by enzymes, but it can occur simultaneously with – and sometimes even initiated by – abiotic process such as photodegradation and hydrolysis9. From the chemical perspective, biodegradation can occur in the presence of oxygen (aerobic, Equation 1.1) or in the absence of oxygen (anaeriobic, Equation 1.2), where Cpolymer represents either a polymer or a fragment from an earlier degradation process9.

Cpolymer + O2→CO2 + H2O + Cresidue + Cbiomass (Aerobic biodegradation,1.1)

Cpolymer→ CO2 + CH4 + H2O + Cresidue + Cbiomass (Anaeriobic biodegradation,1.2)

Complete biodegradation is said to occur when no Cresidue remains, and no oligomers or polymers are left to be further broken down9. As polymers represent major constituents in living cells that have a high turnover rate, i.e. they are constantly degraded in response to environmental changes and metabolic requirements, numerous microorganisms are capable of breaking down naturally occurring polymers as a result of millions of years of adaption. However, for many new synthetic polymers invented in the last 100 years (categories 1-6, Fig. 1) which find their way into the environment, such biodegradation mechanisms have yet to be developed. Other key factors affecting polymer biodegradation include copolymer composition and environmental factors such as pH, temperature, and water content9. This suggests that even if a product is made from bioplastics, it doesn’t necessarily mean it will fully decompose. If such products end up in landfills, for instance, the low oxygen content of such an environment impedes complete degradation. Furthermore, although bioplastics fall within category 7 (Fig.1), these plastics aren’t suitable for recycling and can even degrade the quality of plastic if added to a recycled mixture.

In contrast, compostable materials can break down into water, carbon dioxide, inorganic salts and biomass at the same rate as cellulose, or roughly 90 days11,12. In addition, compostable plastics must disintegrate fully and be indistinguishable in the compost while leaving no toxic material behind. Although compostable plastics appear to have more environmental benefits, this material is equally limited by an inability to biodegrade in a landfill and being incompatible with mixed recycled plastics11. When it comes to biodegradable and compostable plastics, these products make for sustainable alternatives only if they are destined for the appropriate composting facilities whereby the specific conditions for their complete biodegradation are met.

In short, today’s environmental pressures have urged the mainstream production of sustainable alternatives to an ever-growing plastic problem. Although socially responsible plastic products exist with the intention of lessening their environmental footprints, their legitimacy as sustainable alternatives lies in their proper disposal and complete integration into a given environment without any adverse or toxic effects. For a more concrete circular economy, products made of glass and metal can be recycled infinitely without losing product quality, have no need for additional virgin material in the recycling process, and do not generate waste during the process3. Ultimately, a future with a reduced plastic impact depends not only on closed-loop recycling habits, but also on consumer education and awareness about how these products are made and disposed of.

References

(1)        Schmuck, D.; Matthes, J.; Naderer, B. Misleading Consumers with Green Advertising? An Affect–Reason–Involvement Account of Greenwashing Effects in Environmental Advertising. J. Advert. 2018, 47 (2), 127–145.

(2)        Lu, C. The Truth about Recycling Plastics. Mitte. 2018. https://mitte.co/2018/07/18/truth-recycling-plastic/

(3)        Sedaghat, L. 7 Things You Didn’t Know About Plastic (and Recycling). https://blog.nationalgeographic.org/2018/04/04/7-things-you-didnt-know-about-plastic-and-recycling/

(4)        Toto, D. The Value of Plastics. https://www.recyclingtoday.com/article/recyclingtoday-1011-plastics-value/

(5)        Dell, J. U.S. Plastic Recycling Rate Projected to Drop to 4.4% in 2018 https://www.waste360.com/plastics/us-plastic-recycling-rate-projected-drop-44-2018.

(6)        A Circular Economy For Plastics In Canada: A bold vision for less waste and more value. http://circulareconomyleaders.ca/downloads/A_Circular_Economy_for_Plastics_in_Canada.pdf

(7)        Hopewell, J.; Dvorak, R.; Kosior, E. Plastics Recycling: Challenges and Opportunities. Philos. Trans. R. Soc. B Biol. Sci. 2009, 364 (1526), 2115–2126.

(8)        Gross, R. A.; Kalra, B. Biodegradable Polymers for the Environment. Science (80-. ). 2002, 297 (5582), 803–807.

(9)        Bastiolo, C. Handbook of Biodegradable Polymers; 2005. Rapra Technology Limited.

(10)      Vroman, I.; Tighzert, L. Biodegradable Polymers. Materials (Basel). 2009, 2 (2), 307–344.

(11)      https://pelacase.com/blogs/news/5-things-you-probably-didnt-know-about-compostable-plastics

(12)     https://www.food.ee/blog/compostable-vs-recyclable-vs-biodegradable/

Boat Antifouling Technology: the problems and the green chemistry solutions!

Boat Antifouling Technology: the problems and the green chemistry solutions!

By Alana Rangaswamy (Vice-President, Dalhousie University Green Chemistry Initiative)

Picture1

The iconic Halifax Ferry is one of many boats to traverse the Harbour every day.

One great part of attending Dalhousie University is living steps away from the ocean. Much of Halifax’s history and development is due to its access to water, both as a naval base and port of call. With the massive amount of boat traffic seen daily by the harbour, marine industries strive to maximize the efficiency of travel. And one major way to do that is preventing small creatures from hitching a ride on your boat, causing drag and lowering the efficiency of your vessel. Enter antifoulants: coatings that kill organisms or otherwise block their ability to stick onto your ship. Antifouling is a necessary technology, but introducing biocidal agents into a marine environment, unsurprisingly, poses many environmental challenges. Let’s take a look at two commonly used antifoulants, their issues, and how scientists have tried to fix them:

Tributyltin 

You may have heard of tributyltin (TBT) as a biocidal agent. TBT is an excellent poison – effectively nonpolar due to its alkyl groups, it’s able to accumulate in organisms, rapidly killing them due to the high toxicity of SnIII. This property makes TBT an extremely effective antifouling agent, however, it easily leaches from boat hull paint into the ocean where it persists due to its high stability. Fortunately, the dangers TBT have been recognized worldwide and use as a biocidal agent has been banned as of 20081. Canada jumped on the bandwagon slightly earlier, with the last TBT-containing paint product registered in 1999.2 With this restriction, the industry is searching for alternatives that are as effective as TBT, without the environmental drawbacks.

Copper

Copper as a bulk metal is naturally antiseptic, promoting the formation of reactive hydroxyl radical species which lead to cell death in living systems.3 Copper has been used on boat hulls since the 1700s, and now usually shows up in paints as its metal oxide4 or as a suspension of copper powder.5 Although copper is less bioavailable than TBT, it persists and continually forms unstable radical species (and can, therefore. wreak ecological havoc) in a marine environment. Since copper is widely considered the new “gold” standard in antifouling, the sheer amount of it present on (and leaching off of) boat hulls today points to a long-term impact.

New Antifouling Tech

Green chemistry and engineering are all about designing cleaner systems that work as well as, or better than, the existing standard. TBT and copper are high bars to clear, but scientists are up to the challenge. As early as 1996, the environmentally benign Sea-Nine antifouling compound had received the Designing Greener Chemistry Award as part of the US EPA’s Presidential Green Chemistry Challenge.6 Sea-Nine is a derivative of isothiazolinone, a 5-membered heterocycle containing nitrogen and sulfur atoms. The compound is acutely toxic to marine organisms at the surface of boats, but biodegrades rapidly in marine environments through a ring-opening mechanism to form non-toxic by-products. Sea-Nine (and its derivatives) is currently present in commercial boat hull paints,7 however, degradation times may vary based on geographical location and local environment8 so our job isn’t done yet.

There are many newer studies in the works. For instance, investigation has been done into using natural products as antifouling agents. Natural products are secondary metabolites produced by microorganisms as a defence mechanism in response to stress. As such, they often have antimicrobial properties, while being naturally biodegradable. For example, 1-hydroxymyristic acid, a simple alpha-hydroxy fatty acid, was isolated from the marine bacterium Shwanella oneidensis. When panels were coated with paint containing the fatty acid, and subsequently immersed in a marine environment, no growth of foulants was observed even after 1.5 years.9 Other studies have added hydrophobic coatings which disrupt the binding interactions between the microorganism and the vessel’s hull, and promote detachment due to the natural flow of the water over the hull.10 Some research has diverted away from chemical modifiers altogether, using microtextures, which remove the flat surfaces required for spores to settle,10 to deter growth. UV-LEDs11 which are mutagenic and cytotoxic at a small scale, have also been used to reduce growth of foulants.

The long history and many methods developed to prevent boat hull fouling demonstrates that this is an important and challenging problem. But many results are promising, and green chemists and engineers are well on their way to solving it.

References:

  1. http://wwf.panda.org/?145704/tributyltin-canned
  2. Health Canada – Consumer Product Safety Registrar

http://pr-rp.hc-sc.gc.ca/ls-re/result-eng.php?p_search_label=antifouling+paint&searchfield1=ACT&operator1=CONTAIN&criteria1=tin&logicfield1=AND&searchfield2=NONE&operator2=CONTAIN&criteria2=&logicfield2=AND&searchfield3=NONE&operator3=CONTAIN&criteria3=&logicfield3=AND&searchfield4=NONE&operator4=CONTAIN&criteria4=&logicfield4=AND&p_operatordate=%3D&p_criteriadate=&p_status_reg=REGISTERED&p_status_hist=HISTORICAL&p_searchexpdate=EXP

  1. Grass, G., Rensing, C., and Solioz, M. Metallic copper as an antimicrobial surface. Environ. Microbiol. 2011, 77, 1541-1547. DOI: 10.1128/AEM.02766-10.
  2. https://www.chemistryworld.com/news/antifouling-coatings-cling-to-copper/3010011.article
  3. http://coppercoat.com/coppercoat-info/antifoul-how-it-works/
  4. https://www.epa.gov/greenchemistry/presidential-green-chemistry-challenge-1996-designing-greener-chemicals-award
  5. https://www.epaint.com/product/sn-1-antifouling-paint/
  6. Chen, L. and Lam, J. C. W. SeaNine 211 as an antifouling biocide: a coastal pollutant of emerging concern. Environ. Sci., 2017, 61, 68-79. DOI: 10.1016/j.jes.2017.03.040.
  7. Qian, P-Y., Xu, Y. and Fusetani, N. Natural products as antifouling compounds: recent progress and future perspectives. Biofouling, 2009, 26, 223-234. DOI: 10.1080/08927010903470815.
  8. Salta, M. et al. Designing biomimetic antifouling surfaces. Trans. R. Soc. A, 2010, 368, 4729-4757. DOI:10.1098/rsta.2010.0195
  9. https://www.pcimag.com/articles/104484-marine-fouling-prevention-solution-to-use-uv-led-technology

 

 

 

The Future of Sustainability in the Younger Generations’ Hands

The Future of Sustainability in the Younger Generations’ Hands

By Alex Waked, Co-chair for the GCI

In the last couple decades, there has been an increasing focus on developing sustainable practices in society to reduce our environmental impact. Probably the most notable effort in this endeavour is the signing of the Paris Agreement within the United Nations Framework Convention on Climate Change, in which 194 states and the European Union have set goals to reduce the global carbon footprint to reasonable levels.

As we progress forward, there will be a need to propagate this mindset to the coming generations. Fortunately, I don’t think there will be too much difficulty in achieving this. A growing number of schools have been instituting environmental- and sustainability-related courses in their curricula. In my opinion, this strategy has been the most effective in conveying the importance of being conscious of any consequences of our actions and learning how to improve.

In the last few years, many of the chemistry courses at the University of Toronto have incorporated green chemistry and safety modules in both the laboratory and theory sections of the courses. The number of factors that we now consider when designing experiments is much larger than in the past. For instance, are the molecules we’re synthesizing going to be very toxic? Can they be safely disposed of? Do we use harmful substances or solvents during the experiment? How much chemical waste is produced?

Picture1

Figure 1. Graphic of the 12 Principles of Green Chemistry, which currently play an important role in designing safe and environmentally benign chemical processes.1

These are all questions that have traditionally been overlooked in the past. However, the description of the 12 Principles of Green Chemistry by Anastas and Warner in 19982 was a huge and essential step forward in the current direction we’re heading of thinking about chemistry from a sustainability and safety perspective. Many student-led groups and schools are now taking initiative in this endeavour.

The earlier and more the students are taught about these topics, the greater the chance it will have of the students developing genuine interests in them. In June of this year, the University of Toronto Schools held their first Sustainability Fair, in which grade 8-9 students participated in a science fair-like event where they worked on sustainability-related projects.

Picture2

Figure 2. Examples of posters at the University of Toronto Schools’ Sustainability Fair in June 2018.3

The GCI was invited to participate in listening to the students’ presentations describing their projects and to give any advice and encouragement to them; three of us, myself included, attended it. I would say there were at least 40 projects in total. These are just a few examples of some the projects:

  • Calculating how much water was saved by reducing shower time over a 2-week period
  • Collecting and recycling e-waste (any old electrical parts) that would traditionally be thrown away in the garbage
  • Calculating the reduction of carbon footprint by biking to work or school instead of driving

There were two things that really stood out to us: one being the range of topics (water reduction, carbon footprint reduction, recycling plastics and electronic waste, and minimizing food waste), and two being the genuine enthusiasm and interest of the students in their projects.

These are the students that will develop into people that will have important leadership roles in society in the future. The prospect of this is what excites me and gives me confidence that the future generations will continue to propel society forward in terms of being even more environmentally conscious and actually walk the walk, and not only talk the talk!

References:

  1. The Green Chemistry Initiative website. Accessed September 13, 2018. <http://greenchemuoft.ca/resources.php&gt;
  2. Anastas, P. T.; Warner, J. C. Green Chemistry: Theory and Practice, Oxford University Press: New York, 1998, p. 30.
  3. Obtained with permission of the University of Toronto Schools.

 

ACS Summer School on Green Chemistry and Sustainable Energy 2018

ACS Summer School on Green Chemistry and Sustainable Energy 2018

By Kevin Szkop and Rachel Hems

The Colorado School of Mines in Golden, CO is a wonderful campus with cutting-edge facilities and a great place to spend a week with 60 young scientists interested in green chemistry. This is where the ACS Summer School on Green Chemistry and Sustainable Energy was held from July 10 – 17. The group consisted of chemists and chemical engineers from North and South America, all with unique perspectives, experiences, and attitudes towards sustainability. Below is a photo of our awesome class!

Picture1

The 2018 ACS Summer School on Green Chemistry and Sustainable Energy class

The program consisted of technical and professional development sessions. A highlight was a life cycle assessment group project and presentation, led by Prof. Philip Jessop from Queen’s University. During Professor Jessop’s lectures, we learned how to think about the “greenness” of a process, and how this often-nebulous concept is best used as a comparative tool. While every process likely has downfalls, using the green chemistry principles and metrics allowed us to think critically about which process has the least downfalls, and how to address these in our work. The assignment included a group project, during which groups of students had to evaluate the merits and drawbacks of 5 synthetic routes to the same product. In this context, we learned that it is not only the reagents that go into a flask, but everything that happens behind the scenes, including shipping of reagents, the type of waste generated, amount of energy consumed, and much, much more. As a synthetic chemist (Kevin), it really made me think about solvent consumption and work up techniques in my own work!

In addition to learning about green chemistry and sustainable energy, there were some great professional development lectures and activities. Dr. Nancy Jenson, the program manager for the Petroleum Research Fund at the ACS, gave an engaging talk on tips for writing research proposals and common mistakes that are made. While she gave examples from her experience at the Petroleum Research Fund, there were many lessons that could be applied to any type of proposal writing.

Another great professional development lecture was given by Joerg Schlatterer from the American Chemical Society. He gave an overview of the ACS’s many resources for young chemists, such as the Chem IDP website for career planning, workshops for prospective faculty organized by the Graduate & Postdoctoral Scholars Office, and the new Catalyzing Career Networking program at ACS National Meetings. As part of the career planning case study, we took some time to make some SMART goals for ourselves for the next two years. I (Rachel) found it’s really helpful to have others share their goals and give suggestions for yours to make them the SMARTest they can be!

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Rafting down Clear Creek

Of course, we also had time to have fun! On the Saturday (also Rachel’s birthday!) we went white water rafting on Clear Creek. The river is mountain fed, so it was very cold, but it was a beautiful warm and sunny day! We had a great time rafting down the river, with a quick stop to jump in for a swim. It was a great way to spend my birthday! Throughout the week-long summer school, there was a decent amount of free time to enjoy the sunshine and the sights around Golden. Some of the fun things we got to do were swim in and raft down the river that goes through ‘downtown’ Golden, an early morning hike up the South Table Mountain, tour the Coors Brewery, and get to know all the other awesome chemists!

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Kevin and Rachel enjoying the Golden nightlife after a long day of learning!

We highly recommend attending this summer school. It is a great opportunity to learn and to meet great people who care about sustainable chemistry! Read more about past GCI members that have attended the ACS Summer School in 2014 and  2017.

More information on the summer school and how to apply can be found online here.

Water Extract of Banana: The Tasty Fruit for Efficient Green Chemistry

Water Extract of Banana: The Tasty Fruit for Efficient Green Chemistry

By Matt Gradiski, Member-at-Large for the GCI

Bananas. They’re a fantastic healthy snack, delicious to bake into bread or flavour medicine, and even the choice speak-and-spell for singer Gwen Stefani. Now, thanks to two excellent reports in 2015, an efficient medium for two sophisticated organic transformations can be added to its list of uses.

Published in Green Chemistry in January 2015, researchers were able to perform Suzuki-Miyaura (SM) cross-coupling in a neat solution of water extract of banana (WEB).1 WEB is made by simply drying the peel of a banana, burning the dried remains, and extracting the ashes with water (Figure 1). What results is a brown-orange liquid holding tremendous catalytic capability.

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Figure 1. Preparation of WEB solution [1]

 Typically, SM coupling requires the addition of external ligands, base, or other reaction promoters that can often be very expensive. The reaction is known to be able to take place in aqueous media; however, organic solvents are usually the more common choice. While the SM reaction still requires a noble-metal palladium catalyst, using a WEB medium for this reaction completely replaces the use of external additives and organic solvents (Figure 2). The only thing better than being able to do your reaction in water, is to do your reaction in water quickly! The longest reported reaction time using this system was 20 minutes, with times as a low as 5 minutes, and yields as high as 99%, all being carried out at room temperature for 12 different products.

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Figure 2. Example of Suzuki-Miyaura coupling in WEB

Extending the scope of WEB’s usefulness, a report in July of the same year in Green Chemistry showed that the medium can also be used effectively for the catalytic Dakin reaction.2 This reaction converts an ortho- or para-hydroxy aromatic aldehyde or ketone into its corresponding benzenediol through reaction with hydrogen peroxide in base (Figure 3).

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Figure 3. Proposed Dakin oxidation mechanism catalyzed by WEB [2]

Similar to SM coupling, the Dakin reaction requires addition of an external base, typically sodium or potassium hydroxide. However, it was found in the study that no external base was required when the reaction was carried out in WEB. The WEB solution was effective enough to initiate the reaction via deprotonation of hydrogen peroxide, generating the nucleophilic hydroperoxide anion that is required for the reaction to take place. All 16 reactions screened in the study were carried out at room temperature with the use of no external additives or organic solvent. Reaction times were as long as 60 minutes, and isolated yields ranged from 90-98%!

But what makes WEB such an efficient medium for green chemistry? Although the exact identity of the active species is currently unknown, the two aforementioned studies gathered valuable information about what could be promoting their reactions from a report in 2007.3 It was identified that banana peels contain a large amount of potassium and sodium carbonate as well as sodium chloride and other trace elements. It was speculated that the high concentration of alkali metal carbonates in WEB was responsible for the acceleration of these organic transformations.

So, the next time you are finished having a banana, don’t monkey around and throw it away! Give it to a chemist in need, it may help them out more than you think!

 

References

1)         P. R. Boruah, A. A. Ali, B. Saikia and D. Sarma, Green Chem., 2015, 17, 1442–1445. DOI:10.1039/C4GC02522A

2)         B. Saikia, P. Borah and N. Chandra Barua, Green Chem., 2015, 17, 4533–4536. DOI:10.1039/C5GC01404B

3)         D. C. Deka and N. N. Talukdar, IJTK, 2007, 6 (1), 72-78.

 

Figures from Boruah et al. 2015 and Saikia et al. 2015 reproduced with the permission of the Royal Society of Chemistry.

Veggie (Scrap) Tales – Are plant-based polymers the answer to our plastic conundrum?

By Molly Sung, Secretary for the GCI

Plastic is one of the most ubiquitous materials on the planet. Everything from our toothbrushes, to pens, take-out containers, or parts used in the automotive or aeronautic industries are made from plastic. What started off as a convenient and cheap alternative to traditional materials has become a global reliance – and it’s taking its toll.

Traditional plastics are petroleum-based – and as we know, petroleum is a non-renewable resource and its extraction, processing, and use contributes to environmental pollution and climate change. When plastic bags were first gaining popularity in the 1950s and 60s, one of the selling points of using plastic bags was that they were more durable and long-lasting than paper,1 but that’s also exactly the problem. Plastic doesn’t degrade easily like paper does, so it starts to accumulate. This accumulation in landfills and, unfortunately, our waters has spurred research in the development of plastics that can break down over time.

An example of a biodegradable plastic is polylactic acid (PLA). The starting material, lactic acid, can be obtained through fermentation of crops such as sugarcane or corn, which can undergo condensation to form short chains (oligomers). Next, these oligomers undergo depolymerization to form lactide, a cyclic ester, which is then polymerized with the help of a catalyst to give PLA, shown in Figure 1.2

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Figure 1. Synthesis of polylactic acid (PLA), a biodegradable plastic, from lactic acid.

PLA performs comparably to the popular commercial plastic polyethylene terephthalate (PET, labelled with the “1” inside the recycling symbol). It is currently used in food packaging (such as disposable cups), as medical implants,2 and has also found renewed popularity as a common filament for 3D printing, but it’s not without its problems. The monomer, lactide, can have varying stereochemistry which influences the final polymer product and the mechanical properties of the plastic. Significant strides have been made in this area of research, but possibly the biggest barrier to using PLA is the competition with the food industry for the starting material. This is incidentally the same problem many first-generation biofuels ran into. But what if we could take food waste and turn it into usable plastics?

While there are some technologies being developed to use non-food materials like cellulose as a bioplastic, many of these methods require fairly harsh reactions. A gentler, water-based approach to make a cellulose-based plastic was recently reported by a research team from the Italian Institute of Technology and the University of Milano-Bicocca in the journal Green Chemistry.3

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Figure 2. Image of the bioplastic films made from different vegetable powders: (A) carrot, (B) parsley, (C) radicchio, (D) cauliflower. Reproduced from Perotto et al. [3].

This new technique uses waste from the food-industry, including carrot, cauliflower, radicchio, or parsley waste. The vegetable matter must first be dried and ground into a micronized powder, but otherwise no further processing or purification is required to make the veggie waste usable in this process. To make the plastic films, the researchers simply mixed the vegetable powder with a weakly acidic solution (5 % HCl w/w) at 40 °C, then removed any residual acid through dialysis and let the suspension dry in a petri dish for 48 hours. This process has a 90 % conversion of the vegetable waste into bioplastic (by weight) and the product has very promising mechanical properties (Figure 2).

In particular, in measuring the elasticity and tensile strength of the bioplastic films, it was found that the carrot film had comparable properties to polypropylene (commonly used for rigid plastic containers – otherwise referred to as number “5” plastics).

The researchers also tested important factors for plastics being considered for food storage applications. First, they studied whether the films would interact with water. The parsley film was found to absorb water fairly readily. Conversely, the carrot filmed exhibited hydrophobic behaviour – an uncommon characteristic for vegetable-derived plastics. This hydrophobic behaviour means that the moisture from food is unlikely to soak through the plastic film or structurally damage it.

One very interesting property of the radicchio waste is that it is rich in anthocyanins. Anthocyanin is what gives radicchio, red cabbage, and beets their vibrant red colour. More importantly, anthocyanins are known anti-oxidants and materials rich in these anti-oxidants are currently being investigated as food-packaging materials that extend the shelf-life of food.4 Unfortunately, these vegetable films tested to be fairly permeable to oxygen, which would offset any benefit from the antioxidant-rich radicchio film. However, the researchers showed that if the vegetable waste was blended with polyvinyl alcohol (PVA), the oxygen permeability can be reduced significantly and was even an improvement on the pure PVA.

Lastly, and very importantly, the researchers tested for the biodegradability of the films. To test the rate of biodegradation, the researchers submerged the carrot film in seawater to measure the rate of oxygen consumption by the seawater organisms responsible for the biodegradation of the film. They found that the film decomposed fairly quickly in 15 days.

These scientists have now demonstrated a very mild process in the synthesis of bioplastics that have mechanical properties similar to one of the most common commercial plastics. They have also made a plastic that, because of the presence of anthocyanins, may have applications in food storage that can help reduce food-waste.

What is especially promising about these bioplastics is how little purification of the vegetable waste is required to make them; however, there are improvements to be made. A major obstacle these materials will face is their performance in wet or humid environments as well as scaling up to an industrial process. It is clear that we need more sustainable materials and these vegetable waste plastics present an exciting new avenue towards biodegradable bioplastics.

 

References

  1. Laskow. How the Plastic Bag Became So Popular. The Atlantic [Online] 2014. https://www.theatlantic.com/technology/archive/2014/10/how-the-plastic-bag-became-so-popular/381065
  2. Gupta et al., J. Prog. Polym. Sci. 2007, 32, 4, 455-482. DOI: 10.1016/j.progpolymsci.2007.01.005
  3. Perotto et al., Green Chemistry, 2018, 20, 804-902. DOI: 10.1039/C7GC03368K
  4. N. Tran, et al., Food Chemistry, 2017, 216, 324-333. DOI: 10.1016/j.foodchem.2016.08.055

 

Figure from Perotto et al. 2018 reproduced with the permission of the Royal Society of Chemistry.

Glycoside Hydrolases: A Doorway to Alternative Energy

Glycoside Hydrolases: A Doorway to Alternative Energy

By Namrata Jain, GreenChem UBC (Invited post!)

Biofuels, in particular bioethanol, are widely accepted as carbon-neutral fuels1, meaning they have no net greenhouse gas emissions; the amount of carbon dioxide produced during their combustion equals the amount fixed from the atmosphere while the plants grow. These fuels provide an alternative to the current outrageous usage rate of fossil fuels. Plant biomass, a renewable and abundantly available natural resource, is used as the main source for bioethanol production.

In order to produce bioethanol, polymeric plant carbohydrates (polysaccharides) must be broken down into the corresponding monosaccharides, followed by fermentation via yeasts. Typically, starch-rich crops such as corn and sugarcane are the most heavily used as carbohydrate sources.

However, since utilization of these starchy sugars in bioethanol production competes with their use as food crops, there has been a recent shift towards utilization of lignocellulosic biomass.1 Lignocellulosic biomass includes cellulose and hemicelluloses present in non-edible parts of plants, and hence reduces dependence on edible, starch-rich crops.

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Figure 1. Structure of a plant cell wall, highlighting xyloglucan, a particular hemicellulose of interest. [2]

Lignocelluloses form an important part of the plant cell wall (Figure 1) and are composed of cellulose, hemicelluloses (such as xyloglucan), and polyaromatics called lignin. These polymers are tough and more difficult to break down to release monosaccharides, as compared to starch. Nevertheless, lignocelluloses are the most abundant biological material on earth and are an untapped resource.1

The complete utilization of this biomass, however, is hindered by the structural complexity of plant cell walls, arising from the heavy crosslinking between hemicelluloses, celluloses, and lignin within, making it difficult to access the degradable polysaccharidic components. Hemicelluloses, such as xyloglucan (Figure 2A), can make up 15-50 % of these lignocellulosic materials and have been the focus of research for optimization to use as a biofuel.

To efficiently break down the lignocelluloses, many types of enzymes are needed. Glycoside hydrolases, one such group of carbohydrate active enzymes, have proven to be very efficient in the hydrolysis of many complex polysaccharides.3 However, more details about the chemical structure of the enzymes, as well as a reliable way of comparing the kinetic activity of various enzymes has been of interest to researchers in the field.

One of the ways of quantifying the kinetic details of such enzymes is by designing chemical probes such as one shown in Figure 2B. Such probes are chemically very similar in structure to the polysaccharide of interest (eg. Figure 2A), and hence can subtly fit into the active site of the enzyme and manipulate its rate of catalysis in a controlled and quantifiable way, making comparisons between enzymes’ kinetics possible.

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Figure 2. Structures of (A) xyloglucan; and (B) xyloglucan oligosaccharide based probe.

These probes can also assist in the crystal structure formation of the enzyme providing key details about the nature of interactions between the enzyme and corresponding polysaccharide and the specific amino acids responsible for its catalytic activities (Figure 3).

The Brumer group at the University of British Columbia4 has recently designed one such probe (Figure 2B) specific for xyloglucan active enzymes (xyloglucanases) by chemically modifying a xyloglucan-derived heptasaccharide. This probe was able to provide valuable information about the kinetics, specificity, as well as structural details of a newly discovered xyloglucanase PbGH5, which is secreted by a microbe residing in the intestinal system of ruminants such as cows.

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Figure 3. Crystal structure of the characterised endoxyloglucanase in complex with the inhibitor. [4]

As more research goes into the design and improvement of such probes, we would be able to develop novel enzyme cocktails that can make bioethanol production more economically and practically viable, leading to gradual decrease in our dependence on fossil fuels for our energy needs.

 

References:

  1. Scheffran J. The Global Demand for Biofuels: Technologies, Markets and Policies. In: Biomass to Biofuels: Strategies for Global Industries. Blackwell Publishing Ltd.; 2010:27-54. doi:10.1002/9780470750025.ch2.
  2. https://en.wikipedia.org/wiki/Cell_wall#Plant_cell_walls
  3. Henrissat B, Davies G. Structural and sequence-based classification of glycoside hydrolases. Curr Opin Struct Biol. 1997;7(5):637-644. doi:http://dx.doi.org/10.1016/S0959-440X(97)80072-3.
  4. McGregor N, Morar M, Fenger TH, et al. Structure-function analysis of a mixed-linkage β-glucanase/xyloglucanase from key ruminal Bacteroidetes Prevotella bryantii B14. J Biol Chem. 2015;291(3):1175-1197. doi:10.1074/jbc.M115.691659.

Greener Alternatives in Organic Synthesis Involving Carbonyl Groups: Dethioacetalization and Iron-Catalyzed Transfer Hydrogenation

By Diya Zhu, Member-at-Large for the GCI

A carbonyl functionality is a functional group composed of a carbon atom double-bonded to an oxygen atom (C=O). It is ubiquitous in nature as well as widely employed and studied in all areas of chemistry. In this blog, we will explore two common synthetic processes involving carbonyl groups with greener alternative reagents.

Dethioacetalization with NH4I

Carbonyl-containing compounds are abundant in nature, expressing a wide range of functionality. As targeted in many natural and non-natural product syntheses, the protection and deprotection of the carbonyl functional groups are critical and often require multiple steps. Common carbonyl protecting groups are dithianes and dithiolanes due to their easy accessibility and high stability under acidic/basic conditions. The traditional dethioacetalization is generally performed utilizing heavy-metal salts such as mercury(II) chloride, silver(II) nitrite, ceric ammonium nitrate, and selenium dioxide, of which the resulting waste is very toxic to the environment.1

From 1989 to 2005, serval hypervalent iodine compounds such as bis(trifluoroacetoxy)-iodobenzene (BTI), Dess-Martin periodinane (DMP), and o-iodoxybenzoic acid (IBX) have been employed as dethioacetalization reagents due to their low toxicity, high selectivity, and metal-ion free nature. While these reagents have a smaller environmental impact, they are still required in excess amount, which is economically wasteful.2, 3

Finally, in 2011, Ganguly and Mondal reported a mild, efficient, and greener dethioacetalization protocol using a catalytic amount of ammonium iodide with hydrogen peroxide.3 In this work, the deprotection was carried out with 10 mol% of nontoxic ammonium iodide and 30% hydrogen peroxide as the terminal oxidizer in an aqueous medium in the presence of sodium dodecylsulfate (SDS). This protocol (Figure 1) shows a high yield (>90%) deprotection of 1,3–dithianes and dithiolanes of activated aromatics and even deactivated and sterically encumbered substrates. The high tolerance, low environmental impact, mildness, operational simplicity, high throughput, and generality of the protocol make it an intriguing alternative.

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The greener dethioacetalization protocol by Ganguly and Mondal. [3]

Iron-catalyzed transfer hydrogenation with formic acid

Various catalyst systems for the reduction of carbonyl compounds have been established, such as Meerwein–Ponndorf–Verley (MPV) reduction.4 However, only a handful of protocols were reported for the transfer hydrogenation of aldehydes due to the difficulty in controlling the chemoselectivity in the process.

In these conversional protocols of transfer hydrogenation, many side-reactions (for example, aldol condensations) take place after deprotection by the base. The heavy-metal catalysts (such as rhodium, iridium, and ruthenium complexes) are expensive and often poisoned by the substrates, resulting in non-recyclable catalysts and many side-products. In addition, the hydrogenation of carbon-carbon double bonds (C=C) and aldehydes compete, resulting in poor chemoselectivity.5,6 Due to these drawbacks, there was a significant desire for more efficient and environmentally benign catalytic systems.

In the last decade, iron catalysts have received much attention due to their nontoxic, abundant, and inexpensive qualities. In 2013, Beller and his colleagues published an efficient iron-based catalyst system for the highly selective transfer hydrogenation of aldehydes under mild conditions.6 In this system, they suggested that iron-tetraphos complexes [(Fe(BF4)•6H2O and P(CH2CH2PPh2)3) are able to catalyze a wide range of substrates such as aromatic, aliphatic, and α,β-unsaturated aldehydes to the corresponding alcohols in excellent yields (>99%). Without the presence of a base, formic acid is used as a cheap, environmental friendly, and easy to handle hydrogen source. In addition, no significant amounts of side products were observed.

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The iron-catalyzed transfer hydrogenation with formic acid. [6]

In addition to these two examples, many chemical companies promote the idea of green chemistry and offer more green choices to reduce environmental impact without compromising the quality and efficacy of research.7

 

References:

  1. J. Corey, B. W. Erickson, Journal of Organic Chemistry 36 (1971), 3553; E. Vedejs, P. L. Fuches, Journal of Organic Chemistry 36 (1971), 366.
  2. S. Kirshnaveni, K. Surendra, Y. V. D. Nageswar, K. R. Rao, Synthesis 15 (2003), 2295. DOI: 10.1055/s-2003-41055
  3. C. Ganguly, P. Mondal, Synthetic Communications 41 (2011), 2374. DOI: 10.1080/00397911.2010.502995
  4. Gladiali, E. Alberico, Chemistry Society Reviews 35 (2006) 226. DOI: 10.1039/B513396C
  5. S. M. Samec, J.-E. Bäckvall, P. G. Andersson, P. Brandt, Chemistry Society Reviews 35 (2006), 237. DOI: 10.1039/b515269k
  6. Wienhöfer, F. A. Westerhaus, K. Junge, M. Beller, Journal of Organometallic Chemistry 744 (2013) 156. DOI: 10.1016/j.jorganchem.2013.06.010
  7. Sigma Aldrich Alternative Product Page. http://www.sigmaaldrich.com/chemistry/chemistry-products.html?TablePage=119262253 (accessed Oct 15, 2017).

Green Chemistry at CSC2017 – The 100th Canadian Chemistry Conference and Exhibition

By Kevin Szkop and Alex Waked

This year, the GCI partnered with the Chemical Institute of Canada (CIC), the organizing body of the CSC2017, to be closely involved in various aspects of Canada’s largest chemistry meeting.

In collaboration with GreenCentre Canada and CIC, the GCI organized a Professional Development Workshop as part of the CSC2017 program. This event consisted of four components:

The green chemistry crash course, led by Dr. Laura Reyes. Laura is a founding member of the GCI, and is now working in marketing & communications with GreenCentre Canada.

A case study, led by Dr. Tim Clark, Technology Leader at GreenCentre Canada. The case study gave attendees a unique opportunity to learn about some projects that GreenCentre has been developing and in collaboration with peers, learn how to find applications for new intellectual property (IP) and how to make contacts within relevant companies.

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Dr. Tim Clark leading the GreenCentre Canada Industry Case Study

Career panel discussion, sponsored by Gilead, featuring members of academia and industry.

A coffee mixer for an opportunity for informal networking.

 

Supplementary to the Professional Development Workshop, the GCI organized a technical session, co-hosted by the Inorganic, Environmental, and Industrial sections of the conference. This new symposium, entitled “Recent Advances in Sustainable Chemistry”, brought together students, professors, industry, and government speakers to showcase a diverse and engaging collection of new trends in green and sustainable chemistry practices across all sectors of chemistry. Highlighted talks included Dr. Martyn Poliakoff from the University of Nottingham, also a CSC2017 Plenary Lecturer, Dr. David Bergbreiter from Texas A&M University, and Dr. William Tolman from the University of Minnesota.

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Dr. Martyn Poliakoff teaching the audience about NbOPO4 acid catalysts found in Brazilian mines

Dr. Bergbreiter’s lecture was an engaging one. His enthusiastic approach to the use of renewable and bio-derived polymers as green solvents was captivating to both industrial and academic chemists.

Dr. Martyn Poliakoff, a plenary speaker at the conference, gave a phenomenal talk during the first day of the symposium. His charismatic style complimented perfectly the cutting-edge research ongoing in his group at the University of Nottingham. Particularly interesting was the use of flow processes in tandem with photochemistry to yield large quantities of natural products useful in the drug industries.

Dr. Tolman’s talk was of interest to essentially anyone working in an academic environment, especially for student run groups, like the GCI, with both academic interests as well as safety awareness initiatives. In the first part of the talk, synthetic and mechanistic studies of renewable polymers were discussed. The second part shifted focus to student-led efforts to enhance the safety culture in academic labs, which stood out from most of the other talks in our symposium.

One highlight was a group of graduate students at the University of Minnesota organizing a tour of Dow Chemicals to observe the work and safety codes in an industrial setting, which they used as a lesson to bring back to their own research labs. This caught the eye of most of the GCI members, which inspired us to organize a similar day trip in the future.

In further efforts to make our symposium accessible to undergraduate and graduate students, the GCI partnered with GreenCentre Canada to award five Travel Scholarships to deserving students from across Canada to provide financial aid to participate in the conference.

We thank all of our speakers, both national and international, for their participation in the program. It was a great success!