Investigation on Ageing Characteristics of Short Nylon-6 Fibre Reinforced NBR Composites

The ageing characteristics of nylon 6 fibre reinforced NBR composites have been analysed by exposing them to degrading agents such as heat and gamma (γ) radiation. The effects of fibre loading, curing systems and bonding agents on the retention of tensile properties of the composite samples which were exposed to these degrading agents have been studied. The addition of fibres improves the ageing resistance of NBR. The DCP cured composites exhibit a reduction in their ability to retain the elastic modulus as the thermal ageing period increases from 7 to 14 days, whereas sulfur cured composites show a reverse trend. The efficiency for the retention of modulus of sulfur cured samples increases as the dosage of γ-radiation increases from 5 to 10 Mrad whereas a higher dose of 15 Mrad lowers it. However, the DCP cured samples show a continuous reduction in their ability to retain modulus. The composite system containing hexa-resorcinol as the bonding agent has better resistance to heat and γ-radiation than the unbonded one.