Synthesis of biobased polyacetals: a review

Abstract

The molecular structure of a polymer is a key determinant of the properties and thus potential applications of the bulk material. The presence of acetal functional groups in a polymer can impart advantageous characteristics such as reprocessability, degradability, and recyclability. Many biobased monomers contain functional groups amenable to acetal formation, and a variety of polyacetals have been synthesized from renewable starting materials. These polymers range from elastomers to rigid materials, with their diverse mechanical properties depending on both the acetal units and other structural features of the polymers. A partially biobased poly(acetal-ester) with the trade name Akestra is commercially available and can be used in food packaging applications. In this review, the synthesis and properties of biobased polyacetals are surveyed with an emphasis on the sustainability advantages offered by these materials. A brief overview of polythioacetals, the sulfur analogs of polyacetals, is also included.