2017 年 50 巻 p. 89-94
Poly (L-lactide) (PLLA), which is one of representative polymers with biodegradability, has attracted large interest in the biomedical fields such as implantable scaffolds, suture thread, nano-particles and so on. In this study, novel ABA-type tri-block copolymers, PLLA-b-poly (tetramethylene glycol) (PTMG)-b-PLLA, with different lengths of PLLA was synthesized quantitatively by anionic polymerization, and they were evaluated thermal and mechanical properties of the soft materials made from ABA tri-block copolymers. It was clarified to improve brittleness by forming covalent bond between PTMG and PLLA, and changing the tacticity of PLLA segment. This ABA tri-block copolymer is consisting of PTMG as soft segment and PLLA as hard segment. In addition, PTMG cannot adsorb water because of hydrophobicity, but PEG, which is the most common polymer in the biomedical field, can absorb water. Therefore, the block polymer with PTMG may possess great dimensional stability in the water. These polymers and synthetic method are promising for novel soft-materials for biomedical applications.
