Tensile properties and in vitro degradation of P(TMC-co-LLA) elastomers

P(TMC-co-LLA) elastomers have shown great potential for various biomaterials applications. This study investigated properties key to such applications. Six statistical copolymers with 16 to 49 mol% TMC were synthesized and it was found that the LLA sequence length changed from 14 to 3 for the copolymer series while the M[combining macron]_n decreased from 63 to 31 kg mol^-1 with increasing TMC content. The thermal properties showed lower T_g values with increasing TMC content which agreed with the Fox equation. Solvent cast films exhibited Young's modulus values between 2.8 and 271 MPa, ultimate tensile strength of 0.6-15.5 MPa and elongation at failure from 356 to 1287%. In vitro degradation in PBS at 37 °C over 34 weeks demonstrated an induction period of 9 weeks during which the water content was minimal for all copolymers. Copolymer films with 21 or greater mol% TMC were found to undergo homogeneous bulk degradation, while films with 16 mol% TMC underwent heterogeneous bulk degradation.