STTR Phase I: High-performance biopolymer platform for sustainable, safe packaging

The broader impacts of this Small Business Technology Transfer (STTR) Phase I project are rooted in the reduction of per- and poly-fluoroalkyl substances (PFAS) and plastics such as polyethylene (PE) as barrier coatings for paper-based packaging. The industry is seeking to phase such plastics out as they are non-renewable, non-degradable, carry health risks via ingestion of microplastics, and are energy-intensive to produce and poorly recyclable, contributing to greenhouse gas emissions. With PFAS linked to reproductive and developmental abnormalities, immunotoxicity, carcinogenicity, thyroid damage, and many other health risks, upcoming legislative bans on its use in the food packaging industry have left suppliers without adequate replacements. Biodegradable bioplastics are among the most sought-after technologies to replace conventional plastics but are hampered by their use of food crops as the primary raw material, which adversely affects product sustainability and limits commercial feasibility. The proposed biodegradable bioplastic technology 1) uses abundant agro-industrial wastes as the raw material to drive down costs while supporting sustainability and 2) has significant technical performance advantages (i.e., mechanical properties, tunability, scalability) over current bioplastics. This innovation is poised to advance the market for commercially viable, biodegradable bioplastics, enabling the replacement of both PE-based plastic coatings and PFAS-based coatings. The proposed project seeks to develop and validate a platform to deliver biodegradable coating solutions for the packaging industry. Customer discovery has revealed an unmet need for sustainable coatings with the properties needed for mechanical processability at scale (melting temperature, flexibility) and barrier performance of the coated fiber-based product (water vapor, liquid holdout, melting temperature, flexibility). While industry experts point to advanced polyhydroxyalkanoate (PHA) bioplastics as a potential technical solution, the scalable production of PHAs with medium-chain length (MCL) comonomers that improve processability and range of applications has remained out of reach. A fermentative process has been developed to overcome this hurdle in which sugars obtained from hydrolysis of lignocellulosic waste are fermented using inhibitor-resistant recombinant microorganisms with modifications that direct feed components toward P4HB (poly-4-hydroxybutyrate)-based MCL copolymer synthesis. This novel technology enables the production of high-performance, fully biodegradable, and tunable P4HB-co-MCL copolymers fit for a range of applications. Phase I objectives are: 1) Create a process for producing P4HB-co-MCL copolymers from non-structurally related feedstocks and 2) Demonstrate industry-relevant mechanical and barrier properties of developed copolymers. This will establish commercial viability of the platform to transform waste feedstocks into P4HBs with desirable and tunable mechanical properties amenable for commercial adoption. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.