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Improved thermosets obtained from diglycidyl ether of bisphenol A/4,4′‐diaminodiphenylsulfone based on a new epoxy‐terminated hyperbranched polymer
Author(s) -
Jiang Hao,
Wang Rumin,
Farhan Shameel,
Zheng Shuirong
Publication year - 2015
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4982
Subject(s) - epoxy , diglycidyl ether , materials science , glass transition , thermosetting polymer , dynamic mechanical analysis , bisphenol a , composite material , flexural strength , gel permeation chromatography , izod impact strength test , polymer , composite number , bisphenol , fourier transform infrared spectroscopy , toughness , chemical engineering , ultimate tensile strength , engineering
A new hyperbranched polymer ( HBP ) with a flexible aromatic skeleton and terminal epoxy groups was synthesized to improve the toughness of diglycidyl ether of bisphenol A. The HBP was characterized using nuclear magnetic resonance, Fourier transfer infrared spectroscopy and gel permeation chromatography. The effect of HBP on the thermomechanical and mechanical properties of modified epoxy systems was studied. For evaluating the efficiency of the modified epoxy systems, composite samples using glass fiber cloth were molded and tested. Using dynamic mechanical analysis, a slight reduction in glass transition temperature ( T g ) with increasing HBP content was observed. Analysis of fracture surfaces revealed a possible effect of HBP as a toughener and showed no phase separation in the modified resin systems. The results showed that the addition of 15 phr HBP maximized the toughness of the modified resin systems with 215 and 40% increases in impact and flexural strengths, respectively. T g and heat resistance of cured modified resin systems decreased slightly with an increase in HBP content and, at 15 phr HBP , only a 2.6% decrease in thermomechanical properties was observed. Meanwhile, a molded composite with HBP showed improved mechanical properties and retention rate at 150 °C as compared to that made with neat resin. © 2015 Society of Chemical Industry