Division/Committee: 26th Annual Green Chemistry & Engineering Conference

This symposium will highlight the contributions made towards fundamentally understanding, developing, and commercializing biobased polymers via sustainable production processes as well as identify challenges to overcome. Specifically, we invite submissions from individuals across academia, government and industry that address various challenges in this field by: (1) designing complex polymers and polymer composites from a combination of biobased monomers and other biomass constituents, (2) understanding the fundamental processing-structure-property-toxicity relationships of the chemicals, monomers, and resins utilized to produce biobased polymers and polymer composites, (3) applying the principles of green chemistry and engineering towards biobased polymer production as effectively and economically as possible and (4) conducting quantitative economic and life cycle assessments of biobased polymers and polymer composites. Presenters will be asked to participate in a panel to share their perspectives on the growth, challenges, and potential of the field at the conclusion of the session. Abstract submissions from individuals across varied sectors, backgrounds and career stages are encouraged.

Division/Committee: 26th Annual Green Chemistry & Engineering Conference

Refrigeration and air-conditioning systems are widespread throughout modern society, from the refrigerated cold chain that provides fresh foods and storage of medicines to the air conditioning of homes and buildings. In 1987, the Montreal Protocol phased out chlorofluorocarbon (CFC) refrigerants because of their high ozone depletion potential (ODP). The replacements, typically mixtures of hydrofluorocarbons (HFCs), are safe for the Earth's ozone layer, but most have high global warming potentials (GWPs). HFCs account for 7.8% of total global greenhouse gas emissions, with 63% of that from indirect emissions (i.e., energy for running the system). As a result, 197 countries signed the Kigali agreement in 2016 to phase out high-GWP HFCs and more recently the the AIM Act, which was included in the Consolidated Appropriations Act, 2021, directs EPA to phase down production and consumption of HFCs in the United States by 85 percent over the next 15 years. A global HFC phasedown is expected to avoid up to 0.5° Celsius of global warming by 2100. The symposium will focus on technological innovations for the design of new refrigerants, cooling technologies, and refrigerant recovery processes to shift the refrigeration and air conditioning (RAC) industry towards a more circular economy with lower environmental impact.

Supporting understanding of how to incorporate and centralize green and sustainable chemistry in the undergraduate majors and non-majors’ curricula is becoming ever more important. However, most of the currently available instructional materials have been developed as “add-ons” to a more traditional curriculum, and often include sets of confirmatory laboratory exercises and assessments that focus on recall of knowledge fragments. We have proposed that by developing a theoretical framework to guide curriculum and assessment developers we can better determine how green and sustainable chemistry should be built into curricula.

In this presentation, using our framework, we will focus on the development of assessments that have the potenital to elicit evidence about what students know and can do in the context of green chemistry. We will use the principles of evidence centered design and provide examples of such assessments that include scientific and engineering practices such as defining problems and designing solutions.

Toxicology, while central to the goal of designing safer chemicals and enshrined in principles of the Green Chemistry, is in some respects the least developed of the green chemistry principles and the most difficult to quantify; this makes assessing chemical substitutions especially difficult when evaluating trade-offs, as is often the case when doing life-cycle analysis. In many instances, the hazards of a chemical are often only established after a chemical has been on the market for decades, and even then, the nature of the data often makes it difficult for regulatory agencies to act decisively and equally difficult for chemists to use the information to design away toxicity. Toxicology, therefore, needs to change from a reactive science which finds hazards slowly (and often with great expense) once products are on the market to a more proactive science. This would mean not only an improved ability to predict toxicity from structure, but also methodologies that can quickly establish hazards, and are able to identify hazards not only in an animal model in a laboratory, but identify hazards that result from the actual use-pattern of the chemical. This is critical as many chemicals, such as plasticizers, are often subject to a wide variety of environmental conditions and therefore create a variety of potential degradation products.

This will entail a new vision of toxicology that focuses on molecular mechanisms in vitro in place of black box animal models, uses interdisciplinary approaches, and has tools tointegration of disparate qualitative and quantitative data. Critically, it will also mean including better environmental surveillence of the chemicals we are exposed to and better exposure models, as well as data analysis methods suited for an "exposome" based approach for toxicology.

The separation of desired compounds from crude mixtures via mass-directed purification has been available for many years. Typically, this process generates 5-50 mg of product and requires large volumes of solvent. This results in excess material for initial testing, as well as large quantities of solvent consumption and waste. A process (ug-HTPP) has been developed at Amgen to purify microgram quantities of product, employing mass-directed purification via an analytical-scale system, while using and generating dramatically reduced amounts of both solvent and waste as well as reduced quantities of chemical starting materials. This talk will discuss the background and implementation of this technique, as well as how it has improved efficiency while reducing cost and the environmental impact of small-scale, targeted library synthesis and purification.

The U.S. Environmental Protection Agency (EPA) reviews new chemicals under the Toxic Substances Control Act (TSCA) prior to commercialization. During its review, EPA reviews the hazards and exposures related to the new chemical, using models and analogs when data on the substance may be unavailable. At the end of the review, EPA makes a determination and, depending on the outcome determination, in most cases, EPA imposes a regulation. Frequently, new chemicals face scrutiny and the imposition of regulatory burdens, and existing chemicals do not. While many restrictions may not seem burdensome, they often restrict the chemical in ways that pose significant disincentives to commercial use over the incumbent existing chemical.