Influence of Polyether Segment Length on Mechanical Properties of Cured Epoxy Resins Based on Amino-terminated Poly(ethylene glycol) and Diglycidyl Ether of Bisphenol

An advanced amorphous AB-type thermosetting resin without nanophase separation was synthesized via directly moulding diglycidyl ether of bisphenol A(DGEBA) and α,ω-bisaminophenyl terminated poly(ethylene glycol)(BATPE). The stress-strain curve, dynamic mechanical thermal analysis and morphologies of impact fracture surfaces of the cured products were investigated as functions of flexible poly(ethylene glycol) segment length(PE). The results show that the homogeneous epoxy resin without nanophase separation are available by incorporating poly(ethylene glycol) segments into epoxy crosslinked networks via chemically linked with DGEBA at both terminals, beneficial for increasing free volume fractions and strain relax rates. When PE is extended, the glass transition temperature, the room-temperature Young′s modulus and tensile strength of the cured products decrease while toughness, elongation and modulus loss factors increase. The elastic mo-dulus of the cured products at low temperature(i.e. -40 ℃) enhances with increasing PE. Consequently, thermosetting epoxy resins based on BATPE-DGEBA which exhibits excellent tensile strength, modulus and impact strength at moderate and low temperature are obtained by facile optimization of PE.