Study of hygrothermal ageing on properties of polyester / glass composites

Abstract

This study presents hygrothermal degradation of unidirectional glass fiber reinforced polyester composites (GFRPC). Water absorption of GFRPC immersed in distilled water (DW) at RT and river water (RW) at different temperatures was studied. Water absorption of GFRPC immersed in distilled water increased with time and temperature except for samples immersed in river water at 60°C. Moisture absorption (%) in GFRPC increased with increase in fiber content. Degradation of properties [loss tangent (<i>tan </i><i><img src='/image/spc_char/delta1.gif' border=0></i>), glass transition temperature (<i>T</i><i>_g</i>) and storage modulus (<i>E’</i> )] was determined after moisture saturation and drying of specimens using dynamic mechanical analyser (DMA). <i>E’ </i>and <i>T</i><i>_g </i>decreased after moisture absorption for all specimens. <i>T</i>_<i>g</i> showed an almost complete recovery after drying in most cases, whereas <i>E’ </i>reduced permanently after hygrothermal conditioning.