To address the issues of poor toughness and insufficient functionality of poly(ethylene terephthalate)(PET), a series of organosilane copolymerization-modified PET copolyesters (SPET) were prepared by the direct copolymerization of terephthalic acid (PTA) and ethylene glycol (EG) with dihydroxy-terminated polydimethylsiloxane (PDMS). In this study, the influence of the molecular weight of PDMS on its microstructure and macroscopic properties was investigated systematically. The results showed that the intrinsic viscosity [eta] of all the synthesized SPET was greater than 0.7 dL/g, and the introduction of PDMS disrupted the regularity of the PET molecular chains,thereby reducing the crystallinity of SPET. When the molecular weight of PDMS was 2000 g/mol,microphase separation occurred between PDMS and PET, producing a nanoscale "island" structure at their interface, enhancing the mechanical properties of SPET. Among them, SPET2exhibited excellent mechanical performance, with a tensile strength and elongation at break of 56.4 MPa and 502.8%, respectively, which were12% and 43% higher than those of neat PET, respectively. The corresponding impact strength reached 11.68kJ/m2, which was4.7 times that of PET. Driven by thermodynamics, PDMS would migrate to and enrich the surface of SPET, decreasing the surface energy of SPET and endowing the SPET material with excellent antifouling and flame-retardant properties [GRAPHICS] .
原文链接
分享
引用
