SUSMER INC — Department of Energy STTR Phase II: 08b

Description

Plastics are indispensable materials for modern life and the global economy, but current practices in the generation, use, and disposal of commodity plastics are largely unsustainable, causing severe worldwide plastics pollution and enormous energy and materials value loss in the economy. In particular, plastics are a material of choice in packaging applications, but they are currently designed for performance, price, and durability, not for chemical recyclability. Next-generation plastic packaging materials must be designed and manufactured with recyclability built into their performance properties for a circular plastics economy. SusMer will develop next-generation plastic packaging materials both derived from bio-based feedstocks and designed with full chemical recyclability built into their performance properties. Such bioplastic packaging materials possess not only mechanical strength and thermal stability of commodity plastics for practical use but also full chemical recyclability, via facile depolymerization by thermo-chemical means, to recover their building-block monomers with quantitative selectivity and purity for virgin-quality polymer reproduction. This closed monomer-polymer- monomer loop can be exercised repeatedly, in principle, ‘infinitely’, thereby addressing plastics' end-of- issues by this circular plastics economy approach. The critical preliminary results obtained to date from small laboratory scale and Phase I studies demonstrated that the designed fully recyclable bioplastic packaging materials exhibit superior recyclability or mechanical and barrier properties to the existing petroleum-based or bio-based packaging materials. Ongoing Phase I work plan was successfully executed, and its tasks were accomplished by hitting the major milestones. First, we have achieved the scale-up synthesis of the specifically designed monomer up to 1 kg. Second, we have developed the scale-up synthesis of the most promising copolymer bioplastic up to 1 kg. Third, we have also developed the scale-up synthesis of homopolymer bioplastic, for high-end refractory application, and produced up to 0.5 kg. Accordingly, the project in Phase II will further: (1) achieve the scale-up synthesis (5 kg to 10 kg) of the designed bio-based monomer, the building block for packaging plastics with a closed-loop lifecycle; (2) develop the scale-up synthesis (5 kg to 10 kg) of the most promising copolymer bioplastic as fully recyclable packaging material; (3) scale-up synthesis (1 kg to 2 kg) of homopolymer bioplastic; and (4) characterize the thermal, mechanical, rheological, and barrier properties, as well as examine the chemical recyclability, of the resulting copolymer bioplastics, thereby identifying the most promising bioplastic packaging materials. The herein designed fully recyclable bio-based plastics are intended for use as next-generation packaging materials that address not only the poor recyclability and degradability of the current petroleum-based packaging materials, but also the poor mechanical or barrier properties of the currently most promising bio-derived packaging plastics. Hence, the proposed work represents a circular economy approach to plastic packaging materials that meet the three criteria set for the DOE’s FOA on Designing Plastics for a Circular Carbon Economy by: (a) utilizing bio- based feedstocks; (b) addressing end-of-life issues; and (c) showing characteristics of performance- advantaged plastics.