Abstrakt: |
ABSTRACT Epoxide-terminated hyperbranched polyether sulphones (EHBPESs) with different backbone structures were synthesized and used as tougheners for diglycidyl ether of bisphenol-A (DGEBA) curing system, which result in nonphase-separated cured networks. Effects of backbone structure (at comparable degree of polymerization) and loading contents on the mechanical and thermal properties of cured hybrids were investigated. The hybrid containing EHBPES3, which has the most flexible backbone, shows the best mechanical performance and highest glass transition temperature ( Tg). Compared with unmodified system, the impact strength, tensile strength, elongation at break of the hybrid containing 5% EHBPES3 increased by 69.8%, 9.4%, and 60.2%, respectively. The balanced improvements were attributed to the increased crosslink density and fractional free volume as well as the unique inhomogeneous network structure because of incorporation of hyperbranched modifiers with proper structure and loading contents. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41910. [ABSTRACT FROM AUTHOR] |