Biodegradable triblock copolymers based on 1,3-trimethylene carbonate (TMC) and different lactides (i.e. D,L-lactide(DLLA), L-lactide (LLA), D-lactide (DLA)) designated as poly(DLLA-TMC-DLLA), poly(LLA-TMC-LLA) and poly(DLA-TMC-DLA) were prepared and their mechanical and thermal properties were compared with those of high molecular weight poly(TMC) and poly(TMC-co-DLLA) statistical copolymers. Triblock copolymers containing crystallizable LLA or DLA segments perform as thermoplastic elastomers (TPEs) when the poly(lactide) blocks are long enough to crystallize. In blends of poly(LLA-TMC-LLA) and poly(DLA-TMC-DLA) triblock copolymers, stereo-complex formation between the enantiomeric poly(lactide) segments occurs as demonstrated by differential scanning calorimetry and light microscopy. These blends have good tensile properties and excellent resistance to creep under static and dynamic loading conditions.
- Block copolymers
- Creep resistance
- Degradable thermoplastic elastomers
- Phase separation