Biodegradability, reprocessability, and mechanical properties of polybutylene succinate (PBS) photografted by hydrophilic or hydrophobic membranes

The biodegradability and the reprocessability of surface-modified polybutylene succinate (PBS) covalently grafted by hydrophilic or hydrophobic membrane were investigated. The original ungrafted PBS already possesses desirable mechanical and thermal properties, which are very close to those of widely used polyolefins such as polyethylene and polypropylene, but the intrinsic inflexible biodegradability of PBS is still limiting its practical use. Controlling the biodegradability and the reprocessability of PBS, therefore, is necessary to extend the usage of PBS. In this research, the surface of PBS was modified by the photografting polymerization of hydrophilic acrylic acid (AA) and hydrophobic styrene (St) monomers. The surface of PBS became more hydrophilic by increasing the reaction time of the photografting polymerization of AA (or hydrophobic when St was used). Additionally, to estimate the reprocessability of the photografted PBS, the surface-modified PBS was carefully remolded and hence the grafted-membrane was evenly dispersed in the reprocessed and recycled PBS. The structural and mechanical analyses of the modified PBS revealed that the biodegradability and the reprocessability of PBS were effectively controlled by the surface modification via the photografting polymerization and the successive internal dispersion of the grafted membrane. These experimental results may highly provide a new possibility of the extensive use of PBS as an alternative material for polyolefins.