Multiblock alicyclic/aliphatic polyesters. Evaluation of the polymer's susceptibility to enzymatic degradation

Abstract

Multiblock polyesters were prepared from dimethyl 1,4-cyclo-haxanedicarboxylate (DMCD) (or dimethyl terephthalate, DMT ) and 1,4-butanediol (1,4-BD) with dodecanedioic acid (DA). Polymers were prepared by two-stage technique namely transesterification and polycondensation from the melt. The multiblock polyesters obtained were characterized by viscosity measurements, differential scanning calorimetry and tensile test. Polymers were exposed, in vitro, to Rhisopus delemar lipase solution. The enzymatic degradation was monitored by changes in molecular weight (from gel permeation chromatography) and estimated by the weight loss of the polyester films in a buffer solution with the enzyme at 37°C. Performed studies have shown that the enzyme Rhisopus delemar is able to alter the structure of the alicyclic/aliphatic polymer (PCD-DA) to a greater extent than the structure of aromatic/aliphatic copolyester (PBT-DA).