Toughening of aromatic diamine-cured epoxy resins by modification with N-phenylmaleimide-styrene-p-hydroxystyrene terpolymers

✍ Scribed by Takao Iijima; Norio Suzuki; Wakichi Fukuda; Masao Tomoi

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 890 KB
• Volume: 31
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(95)00019-4

✦ Synopsis

N-phenylmaleimide-styrene-p-hydroxystyrene terpolymers (PMSH), containing pendant p-hydroxyphenyl groups as functionalities, were prepared and used to improve the toughness of bisphenol-A diglycidyl ether epoxy resin cured with p,p'-diaminodiphenyl sulphone. The terpolymers were effective as modifiers for toughening the epoxy resin. When using more than 10 wt% of PMSH with ~3.0 mol.% p-hydroxystyrene (HSt) units, the fracture toughness (K,,) for the modified resins increased > 100% with a medium loss of flexural strength and with a retention in flexural modulus and the glass transition temperature. For example, inclusion of 12.5 wt% of PMSH (1.0 mol.% HSt unit, IU, 291,000) led to a 130% increase in K,, The most effective modification for the modified resins could be attained because of the co-continuous structure of the modified resins. The toughening mechanism is discussed in terms of the morphological behaviours of the modified epoxy resin systems.