Imparting Marine Biodegradability to Poly(Ethylene Succinate) (PES) by Blending with a PES-Based Copolymer

In this study, a method was developed for imparting marine biodegradability to poly(ethylene succinate) (PES) by blending it with a marine biodegradable PES-based copolymer containing sebacic acid (SebA), which was denoted as PESSeb15. In a previous study, the marine biodegradability of PES-based copolymers was improved with increasing SebA content, whereas some material properties declined relative to those of the PES homopolymer. The blends prepared at PES/PESSeb15 feed weight ratios of 75/25, 50/50, and 25/75 were analyzed using Fourier-transform infrared spectroscopy, differential scanning calorimetry, and atomic force microscopy, suggesting that PES and PESSeb15 were immiscible. The blends obtained exhibited marine biodegradability even with less SebA content than the copolymers. Tensile and O2 permeability tests of the obtained blends were conducted to investigate the influence on material properties, and tensile moduli, stresses at break, and O2 permeabilities were improved compared with those of PESSeb15. Notably, the 75/25 (w/w) PES/PESSeb15 blend with low PESSeb15 contents exhibited O2 gas barrier properties close to or higher than those of general-purpose polymers commonly used in food packaging, such as poly(ethylene terephthalate), polyethylene, and polypropylene. This research may also be applicable to the development of other high-performance biodegradable materials.