Macromolecular structure design and properties of advanced biodegradable thermoplastic elastomers

Abstract

In this paper, using some bio-based aliphatic diols (1,3-propanediol and 1,4-butanediol) and dibasic acids (succinic acid, adipic acid and sebacic acid), we successfully prepared a novel biodegradable thermoplastic elastomer (BTPE) blocked by crystalline aliphatic hard-segment prepolyester (HPE) and amorphous aliphatic soft-segment prepolyester (SPE) by means of polymerization technologies of melt polycondensation and chain extension reaction. Experimental results showed that the BTPE had glass transition temperature of about –50 °C, melt temperature of about 105 °C, and initial thermal decomposition temperature of above 340 °C. The elongation at break of the BTPE was up to 1100%, and the recovery rate of 100% tensile deformation of the BTPE was above 85%, meanwhile the recovery rate of cycle stretch with 300% strains was above 75%. The BTPE had controllable hardness between 56 and 73 HA, while the tensile strength was between 7.5 and 9.6 MPa. Notably, mass of the BTPE lost up to 68% after 15-d degradation in lipase buffer solution at 37 °C. Also, mass of the BTPE lost up to 57% after 120-d degradation in natural soil. Methyl thiazolyl tetrazolium (MTT) colorimetric assay showed that the relative growth ratio of L929 cells cultured in BTPE extract for 72 h was above 80%, and the cell growth morphology was good, indicating that the BTPE had no obvious cytotoxicity and the evaluation result was first-class qualified. Above results show that the novel BTPE has great development prospects in the fields of environment-friendly materials and biomedical materials.