Fabrication of Porous Poly(3-hydroxybutyrate--3-hydroxyhexanoate) Monoliths via Thermally Induced Phase Separation.

This study deals with the fabrication of biodegradable porous materials from bacterial polyester, poly(3-hydroxybutyrate--3-hydroxyhexanoate) (P3HB3HH), via thermally induced phase separation. P3HB3HH monoliths with topological porous structure were prepared by dissolution of P3HB3HH in dimethyl sulfoxide (DMSO) at 85 °C and subsequent quenching. The microstructure of the resulting P3HB3HH monoliths was changed by the P3HB3HH concentration of the polymer solution. Differential scanning calorimetry and polarized optical microscope analysis revealed that the P3HB3HH monoliths crystallized during phase separation and the subsequent aging. The mechanical properties, such as compression modulus and stress, of the monoliths depended on the 3-hydroxyhexanoate content of P3HB3HH. Furthermore, the P3HB3HH monolith absorbed linseed oil in preference to water in a plant oil⁻water mixture. In combination with the biodegradable character of P3HB3HH, the present study is expected to contribute to the development of bio-based materials.