Infinitely Recyclable Bioplastics (Topic 8, subtopic b)

Plastics are indispensable materials for the modern life and global economy, but current practices in the generation and disposal of commodity plastics are largely unsustainable and causing severe worldwide plastics pollution and enormous materials' energy and value losses to 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 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 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 common plastics for practical use but also full chemical recyclability, via facile depolymerization by thermal or 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-life issues by this circular plastics economy approach. The critical preliminary results obtained to date from small laboratory scale 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. However, such materials must be produced in larger scales for further studies and testing. Hence, the Phase I project will: (1) achieve the scale-up synthesis of two specifically designed bio-based monomers, the building blocks for packaging plastics with a closed-loop lifecycle; (2) develop the scale- up synthesis of three most promising copolymer bioplastics as fully recyclable packaging materials; and (3) 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 for subsequent Phase II studies.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.