How do you describe your research to colleagues?
When addressing plastic waste, we often think of the symbolic PET bottles. However, PET bottles make up only ~12% of the commodity plastic products, while polyolefins are produced as much as 4-5 times of PET bottles (reaching 60% of the plastic market). Typically, most single-use plastics are polyolefins, and these single-use & short-life-span products are the biggest pollution issue. The recycling of polyolefins is quite challenging in many aspects, reflecting the fact that less than 3% of polyolefins are recycled at the current state of the art. For instance, the chemical and biological technologies, which can be more feasibly applied to upcycling PET bottles in advance (e.g., depolymerize wastes to monomers, and then polymerize monomers into new products), are still difficult to handle polyolefin wastes in a similar upcycling route. The chemical recycling of polyolefins mainly focuses on pyrolysis, which holds the promise of eventually valorizing polyolefin wastes into valuable products (e.g., fuels), but the efficiency of this method also depends on energy consumption. Under mild and economic conditions, depolymerization of polyolefins can produce wax-like materials. Waxes are poor in mechanical properties, so is it feasible to regenerate them into new polymeric materials using practical processing methods? Also, how do the miscibility and compatibility of waxes from various plastic products influence the performance of final products (e.g., the tolerance of co-mingles)? And to what extent is depolymerization good in terms of material properties and cost? With these questions, we proposed to conduct a series study on polyolefin waxes, attempting to recycle polyolefin wastes into waxes and then chemically modify them as new feedstock to build polymeric materials (through cross-linking) for open-loop applications that are no longer typical plastics.
How do you describe your research to non-scientists?
Plastic is one of the most symbolic inventions of modern society. We enjoy plastic products because they are versatile and inexpensive for many purposes and applications. Nevertheless, the reality is that every household is pretty much struggling with piles of plastic waste. Each time we go to a grocery store, restaurant, and gift shop, we “purchase” many plastic products, and most of them are packaging materials. Most plastic wastes will end up in landfills or incinerations, and mismanaged plastic wastes are becoming microplastics that pollute everywhere: you can find them in your house’s tap water. In general, the issue of plastic waste is contributing to the global environmental crisis, but we still lack effective strategies and tactics to handle this issue. Hence, as plastic engineers, our task is to develop technologies to combat the massive plastic wastes, facilitating them into a sustainable and manageable cycle. To ensure that we can keep enjoying the convenience with sustainability in mind. In my research, I am thinking about “the other route” that can be more effective than the traditional recycling process of plastic waste. Instead of conventional “plastic-to-plastic” recycling, I look forward to a new insight to “open the loop” of plastic waste.
What public benefit do you hope will come from your work?
There is no doubt that plastic waste is one of the biggest global environmental problems of this century. The public is now even losing confidence in plastic recycling as more ordinary people are concerned whether the plastic waste is completely worthless and considered “trash”. Unlike revealing the environmental impacts, I hope this research will more practically address “how and why we can recycle post-consumer polyolefin wastes via new methods”, with the ultimate goal of reducing plastic products from becoming the wastes that pollute our planet. I believe this ultimate objective is the common desire of all of us.
What difference has the Washington Research Foundation Postdoctoral Fellowship made to your work?
I do sincerely appreciate WRF for awarding this fellowship! In my field, the research funding usually comes from national agencies or industries: the previous case sometimes requires preliminary results to support a long-term project, and the latter case is generally short-term and sometimes demands following specific research directions (e.g., corporate interests). WRF’s postdoctoral fellowship does not look like these two; instead, it helps me and other diligent postdoc researchers to independently manage our long-term project that eventually meets public needs. It provides us the freedom and flexibility to bring our research to reality. Personally, since I put the research of plastic recycling as my career objective, this fellowship significantly boost my early career development. Meanwhile, it is also a great platform for me to meet other awesome people in versatile fields.