Environmental Effects on Short Term Properties of Glass/Polyester Composites

摘要

A series of tests were performed on polyester-glassfiber composites. The tests included static strength tests, effects of hydrothermal and sulfuric acid exposure and elevated temperatures and thermal cycling behavior. The results indicated that elastic tensile modulus and tensile strength of laminates with a fiber orientation of + or - 45 degrees were sensitive to hydrothermal and sulfuric acid immersion. The flexural elastic modulus and flexural strength of 0 degree/90 degree laminates were not highly affected by hydrothermal immersion or sulfuric acid immersion at room temperature. Sulfuric acid immersion at elevated temperatures decreased the values rapidly. The tensile strength and modulus of the + or - 45 degree laminate decreased considerably at elevated temperatures. The flexural properties of the 0 degree/90 degree laminate retained over 80% up to the onset of the polyester-matrix glass transition region. The flexural elastic modulus and flexural strength of the 0 degree/90 degree laminate were insensitive to the thermal cycling while the maximum strain and tensile properties decreased considerably after a single freezing cycle. The glass transition temperature was insensitive to the hydrothermal or sulfuric acid immersion.