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Modification of aromatic diamine‐cured epoxy resins by poly(oxymethylene) or hybrid modifiers containing poly(oxymethylene)
Author(s) -
Iijima Takao,
Sugizaki Atsushi,
Fukuda Wakichi,
Tomoi Masao
Publication year - 1997
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/(sici)1097-0126(199710)44:2<125::aid-pi801>3.0.co;2-l
Subject(s) - diglycidyl ether , epoxy , materials science , glass transition , bisphenol a , polyester , polymer chemistry , prepolymer , composite material , polymer , polyurethane
A copolymer comprising poly(oxymethylene) (POM, polyacetal) was used to improve the fracture toughness of a resin based on diglycidyl ether of bisphenol A (DGEBA) cured with 3,3′‐dimethyl‐5,5′‐diethyl‐4,4′‐diaminodiphenyl methane. POM was a less effective modifier for epoxies and a third component was used as a toughener or a compatibilizer for POM. The third component includes polypropylene glycol‐type urethane prepolymer (PU) and aromatic polyesters. The hybrid modifiers composed of POM and PU were more effective as modifiers for toughening epoxies than POM alone. In the ternary DGEBA/POM/PU (90/10/10wt ratio) blend, the fracture toughness, K IC , for the modified resin increased 50% with retention of flexural properties and a slight decrease in glass transition temperature ( T g ) compared with those of the unmodified epoxy resin. The aromatic polyesters include poly(ethylene phthalate) (PEP), the related copolyesters and poly(butylene phthalate). PEP was most effective of them as a third component in the hybrid modifier. In the ternary DGEBA/POM/PEP (85/15/10) blend, K IC for the modified resin increased 70% with medium loss of flexural strength and retention of T g . The toughening mechanism is discussed in terms of morphological and dynamic viscoelastic behaviour of the modified epoxy resin systems. ©1997 SCI