Volume no :11, Issue no: 2, April 2015

EVALUATION OF THE DURABILITY PERFORMANCE OF GLASS-FIBER REINFORCEMENT EPOXY COMPOSITES EXPOSED TO ACCELERATED HIGROTHERMAL AGEING

Author's: Clarissa Coussirat Angrizani, Branca Freitas De Oliveira and Sandro Campos Amico
Pages: [31] - [47]
Received Date: May 31, 2015
Submitted by:
DOI: http://dx.doi.org/10.18642/jmseat_7100121507

Abstract

Polymeric composite materials present modification of its physical and mechanical properties when exposed to aggressive environments (heat, humidity, ultraviolet radiation, etc.) and this is a serious concern for the manufacturers of composites. Unlike metallic materials knowledge about changes in the properties and characteristics due to degradation environments are still unknown. The level of deterioration depends on the environment and the period to which the material would be exposed. Degradation of polymeric composites can be physical or chemical. The physical degradation is characterized by the ability of the material returns to its original state after being exposed to a hygrothermal ageing after it returns to their original properties after drying. In this context, the aim of this work is to study the influence of accelerated hygrothermal ageing on glass/epoxy unidirectional composite two temperatures. The composites were molded by resin transfer moulding (RTM) with a fiber volume fraction (Vf) of and characterized by water absorption, DMA, TGA and short-beam shear strength (at fiber orientation of 0° and 90°). Comparing water absorption at 50°C and 80°C, it was observed that only the last stabilized. The weight loss may be due to the dissolution of the fiber sizing or unreacted components of the matrix. In the short-beam strength testing, when comparing the samples exposed to 50°C and 80°C, it was observed the possible occurrence of physical degradation (plastification) of the first and second chemical (crosslink second of the matrix). The complexity of the ageing study of composite is due to the fact that a slight change in magnitude of any variable can produce very different results.

Keywords

degradation, hygrothermal aging, unidirectional composite.