Traditional polymers with nontraditional side-chain functionality: Carboalkoxylated polyvalerolactones and polyisoprenes from malic acid and glucose

Abstract

The compounding environmental effects of non-degradable plastics have attracted increased attention to sustainable polymers. This dissertation is focused on producing polymers from plant-based, renewable feedstocks while also emphasizing novel methods to chemically recycle polymers into valuable fragments. Plant-based feedstocks provide reagents with increased oxidation relative to petroleum and offer the opportunity to access traditional monomers with novel functionality. In this document, approaches to producing biobased monomers in addition to ring-opening transesterification polymerization (ROTEP) are introduced (Chapter 1). After, my research (in Part 1) on the two-step synthesis and ROTEP of 4-carboalkoxyvalerolactones is discussed. The ROTEP of these monomers, which are derived from malic acid, can either provide (i) tough and flexible, semicrystalline polyesters that can be chemically recycled by two independent pathways (Chapter 2 and 4) or (ii) an amorphous, hyperbranched polyester also capable of being chemically recycled (Chapter 3). The architecture of the product polymer is determined by the catalyst used for ROTEP or the position of the carboalkoxy on the lactone ring (Chapter 5). These characteristics are unique to this relatively unstudied family of monomers. In Part 2, anhydromevalonolactone, which can be fermented from glucose, is converted into isoprenecarboxylic acid, isoprenecarboxylate esters, and isoprenecarboxamides. These isoprene derivatives are radically polymerized to provide linear polymers (Chapter 6) or crosslinked superabsorbent hydrogels (Chapter 7). This series of polymers may provide a biobased alternative to polyacrylates.