Abstract:
Dynamic vulcanization of natural rubber (RSS) was studied. The effect of methods of vulcanization, i.e. sulphur, sulphurless and peroxide on mechanical, rheological properties, thermal ageing and weathering tests were investigated. Swelling behavior of when using sulphur, sulphurless and peroxide were investigated. Accelerators of mercapto class gave medium scorch time they gave faster onset of cure than peroxide but slower than thiurams which gave the fastest onset of cure of accelerators as a whole, Viscosity of the compounds tended to increase from peroxide, sulphurless, to sulphur system. Vulcanizates with thiuram and a little sulphur showed higher tensile strength, elongation at break and lower modulus than sulphur system. The peroxide system was lower in tensile strength than both sulphur and sulphur-less system but had higher elasticity value more than other systems Thiuram cured accelerators with low sulphur gave better resistance to ageing than sulphur system. Peroxide vulcanizates gave excellent ageing characteristics. In toluene the resistance was weak for all systems however it showed the smallest ratio in peroxide system. Sulphur system showed the best resistance for processing oil (37) and peroxide system showed more resistivety than sulphur-less system