Thermal, mechanical, and dielectric studies on the DGEBA epoxy blends by using liquid oxidized poly(1,2-butadiene) as a reactive component

摘要

Liquid oxidized poly(1,2-butadiene) (LOPB) with multi epoxy groups is synthesized to modify diglycidyl end-caped poly(bisphenol A-co-epichlorohydrin) (DGEBA) cured by 4,4'-diaminodiphenyl sulfone (DDS). FTIR spectra shows that DGEBA and LOPB can be effectively cured by DDS, and the epoxide rubber particles are evenly distributed in the composites till their addition up to 20 wt of DGEBA as seen from the scanning electron microscope (SEM). Their decomposition temperatures (Td) increase with the increase in LOPB addition at around 10 wt of DGEBA while the Td for the composite containing 20 wt LOPB of DGEBA is lower than that of the neat epoxy. The addition of LOPB improves their storage moduli and especially these values at temperatures higher above 150 degrees C; all the composites exhibit higher glass transition temperature (T-g) than that of the neat epoxy, and the maximum T-g reaches up to 255 degrees C for the composite containing 15 wt LOPB of DGEBA. The incorporation of LOPB effectively decreases their dielectric constants and the composite with 10 wt LOPB of DGEBA possesses the lowest one. The synergic improvements in their various properties are attributed to the networks formation via covalent linkage between the two phases in these reactive blends. (C) 2017 Wiley Periodicals, Inc.