Facile synthesis of silicone-toughened unsaturated polyester by hydroxyl-terminated silicone copolycondensation

摘要

A facile method is developed to synthesize silicone-toughened unsaturated polyester (SUP-M) by monomer copolymerization of anhydrides and diols with hydroxyl-terminated silicone. The structures and molecular weights of the SUP-M resins were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography, respectively. The gelation time and mechanical properties, including impact strength, flexural strength, and tensile strength, were investigated. The fracture behaviors were studied by scanning electron microscopy, and their glass-transition temperature and storage modulus were measured by dynamic mechanical analysis. The experimental results showed that the impact strength of SUP-M can be obviously improved through copolymerization with a small amount of silicone without decreasing its mechanical properties. The impact strength, flexural strength, and tensile strength of SUP-M-0.5 are as high as 12.5 KJ m(-2), 131 MPa, and 59 MPa, which are increased by 76.1%, 21.2%, and 6.7%, respectively, compared with those of unsaturated polyester. Impacts on SUP-M with low silicone content produce a large number of evenly and regularly distributed continuous narrow crack bands combined with many evenly distributed branching crazes, which are of great benefit in absorbing a large amount of impact energy. (C) 2017 Wiley Periodicals, Inc.