Biodegradability as an Off-Ramp for the Circular Economy: Investigations into Biodegradable Polymers for Home and Personal Care

Abstract

Metrics & MoreArticle Recommendations CONSPECTUS: Consumer pressure for globe-conscious products is pushing brand-owners big and small to provide transparency on the origin and fate of their ingredients. One such market where sustainable product growth has outpaced market growth is in home and personal care. Products in this space clean or care for our bodies, our homes, our environments, and the materials we encounter every day. Many of these materials are used and then washed down the drain, making the fate of these products a tangible end point for the consumer. Life cycle assessment (LCA) is a well-established methodology for determining potential environmental impacts of products and can be used to quantify the overall carbon footprint of the raw materials, the process to manufacture, and the transportation of the product around the globe.LCAs are calibrated to one metric, often kilograms of carbon dioxide (CO 2 ) equivalents, to capture the overall carbon footprint. One aspect notably absent from many LCAs is the end of life for the product. Interestingly, consumers are driving a push for biodegradable materials that would not persist in the environment, but as materials biodegrade, they release carbon dioxide to the atmosphere. This release of CO 2 places the benefits of biodegradation on the ultimate fate of raw materials in contradiction with carbon reduction methods such as carbon capture and carbon recycling that improve the LCA of a given product. In this Account, we describe the impact of biodegradation on the circular economy and discuss the development of natural, modified natural, and synthetic polymers to provide biodegradable alternatives to less degradable materials in the home and personal care markets. Building a chemical toolbox which can meet the functional and economical requirements of products on the market today while improving their sustainability profile is a huge challenge, which will not have a single answer. Among many current internal research initiatives, one vignette will be highlighted to showcase the research on a synthetic polymer with improved biodegradability for the dish care market. This novel polyelectrolyte, a copolymer of itaconic acid, acrylic acid, and vinyl acetate, was designed to break down into digestible daughter products in a wastewater treatment plant while demonstrating stability both on the shelf and in the dishwasher.

Designing biodegradable alternatives to commodity polymers

“…Until recently, end-of-life products were absent from LCAs, but they have become a topic of interest in recent years, [72][73][74] with special consideration towards the aquatic environment. 29 In striving for a sustainable circular economy, recycled and biobased feedstocks offer the opportunity to transition from petroleum-derived raw materials in the design of polymers, offering potential for biodegradation whilst aiding in the drive for carbon neutrality (Box 1). 75 A factor which cannot be ignored is cost.…”

“…An alternative approach, where recycling may not be feasible, is to produce commodity polymers that degrade rapidly at the end of their use phase. 29 Some interventions to accelerate polymer biodegradation have been limited in their success, however. One strategy aimed at improving the rates of polyolefin degradation involved the addition of ‘prodegradants’ 30 such as complexes of Fe, Co and Mn, to assist in the generation of radicals and hence accelerate abiotic degradation.…”

Highly crosslinked polyesters prepared by ring-opening copolymerization of epoxidized baru nut and macaw palm oils with cyclic anhydrides

“…3 Thus a major challenge in green chemistry is the development of new polymers which are sustainably sourced and degradable at end of life. This will allow the development of a sustainable and potentially circular economy for polymers, 4 but requires the integrated consideration of feedstocks, production methodology and design for degradation.…”

Uniform Polyester-Based Nanoparticles Assembled via Living Crystallization-Driven Self-Assembly as Friction-Reducing Agents in Engine Oil

“…The sustainability and circularity of a material or formulation is no longer just a concept to strive for but is becoming a requirement for all manufacturers to fulfill . Polymers that are typically studied as friction modifiers, such as (meth)­acrylates, possess hydrocarbon backbones. , In order to improve their degradability, and hence potential for circularization, it may be desirable to apply polymers with heteroatom-containing backbones. − A well-studied class of monomer/polymer that has demonstrated controlled polymerization and degradation back to monomer is that of lactones/polyesters. − Polyester materials represent attractive candidates to replace aliphatic hydrocarbons in a range of materials and formulations, such as in tissue engineering or drug delivery devices, capable of closing the loop of a circular economy. − Although degradability may not be desirable during use, the oil environment ensures this is unlikely to occur as a result of the presence of water.…”

“…27−30 The sustainability and circularity of a material or formulation is no longer just a concept to strive for but is becoming a requirement for all manufacturers to fulfill. 31 Polymers that are typically studied as friction modifiers, such as (meth)acrylates, possess hydrocarbon backbones. 32,33 In order to improve their degradability, and hence potential for circularization, it may be desirable to apply polymers with heteroatom-containing backbones.…”