Polyesters of 2-Pyrone-4,6-dicarboxylic Acid (PDC) as bio-based plastics exhibiting strong adhering properties

Abstract

2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable metabolic intermediate of lignin, its bis(hydroxyethyl) derivative (BHPDC) and bis(hydroxyethyl) terephthalate (BHT) were polymerized to prepare the corresponding polyesters carrying the oxyethyleneoxycarbonyl(2-pyrone-4,6-diyl) carbonyl and oxyethyleneoxy-terephthaloyl units [x and y units, resp., x + y = 1] by polycondensation eliminating water and/or 1,2-ethanediol molecules. The polyesters were mostly stable up to 210°C, after that the degradation of pyrone ring commenced. These polyesters exhibited strong adhering properties against metal, glass and surfaces with increasing the x unit content to 0.4-0.6, such as about 50-60 MPa for SUS/polyester/SUS or Al/ polyester/Al samples, by the JIS K 6849:1994 testing method of tensile strength. As the fracturing plane was the midst of the polyester layer and at the interface, the polyester was tenaciously adhering to the metal surface. ©2009 The Society of Polymer Science.