In Situ Synthesis, Crystallization Behavior and Mechanical Properties of Biodegradable Poly(Ethylene Succinate)/Talc Composites

Poly(ethylene succinate) (PES) is a promising biodegradable polyester with excellent thermal and mechanical properties; however, slow crystallization rate has seriously restricted its widespread application. PES/talc composites at low talc contents of 0.5 to 2.0 wt% were synthesized via an in situ polymerization method in this research. The chemical structure, thermal stability, crystallization behavior, crystalline morphology, crystal structure, and tensile mechanical properties of PES/talc composites were extensively investigated with various techniques and compared with those of neat PES. Talc remarkably enhanced the crystallization behavior of PES under different crystallization conditions as an effective nucleating agent. For instance, 2 wt% talc increased the melt crystallization temperature of PES from 46.1 to 58.9 °C at a cooling rate of 5 °C/min and shortened the crystallization half time to 1.95 min from 7.69 min at 66 °C. However, talc remained the crystallization mechanism and crystal structure of PES. The nucleation mechanism of talc on the crystallization of PES was further discussed. The exact nucleation mechanism was still uncertain, which needs further investigation. The mechanical properties of PES/talc composites were dependent on the talc content. For instance, 0.5 and 1 wt% talc decreased the tensile strength values to 34.1 ± 1.9 and 33.7 ± 2.1 MPa from 44.9 ± 1.3 MPa, while the elongation at break values increased to 675.3 ± 24.8% and 560.4 ± 11.9% from 508.0 ± 13.4%, respectively, indicating an increase in toughness. Although the mechanical properties of PES/talc2.0 (2 wt% talc) were inferior to those of neat PES and the other two composites, it still displayed relatively good mechanical properties.