Additive effects on the toughening of unsaturated polyester resins

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:76234

Suspene, L ^[1]; Yang, Y S; Pascault, J P ^[2]

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1. Centre de Recherches et de Technologies de Verneuil, Verneuil-en-Halatte (France)
2. Institut National des Science Appliquees de Lyon, Villeurbanne (France)

An elastomer additive, carboxy-terminated acrylonitrile-butadiene copolymer, was used for toughening in the free radical cross-linking copolymerization of unsaturated polyester (UP) resins. For molded parts, Charpy impact behavior was generally enhanced and the number of catastrophic failures was reduced. The miscibility and interfacial properties of additive and resin blends play important roles in the toughening process. Phase-diagram studies showed that the elastomer additive is immiscible with the UP resin and is phase-separated from the resin matrix during curing. This phase-separation phenomenon is similar to that in the low-profile mechanism of UP resins. Additive-resin system miscibility greatly influences curing morphology. Microvoids occurred in the additive phase of cured resin because of shrinkage stress. The intrinsic inhomogeneity of the polyester network and the existence of microvoids in the final product limit the toughening effect of additives on unsaturated polyester resins. 49 refs., 13 figs., 3 tabs.

• OSTI ID: 76234
• Report Number(s): CONF-900802--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACRYLONITRILE
ADDITIVES
CHARPY TEST
COPOLYMERS
CROSS-LINKING
MECHANICAL PROPERTIES
PHASE STUDIES
POLYESTERS
RESINS
SOLUBILITY
VOIDS