Studies on the curing behaviour and mechanical properties of styrene/methyl methacrylate grafted deproteinized natural rubber latex

The graft copolymerization of styrene/methyl methacrylate (MMA) onto deproteinized natural rubber (DPNR) latex was carried out using ammonium peroxy disulfate (N2H8O8S2) as the initiator. The presence of the grafted polystyrene (PS) and polymethyl methacrylate (PMMA) on the rubber backbone was confirmed by FTIR spectroscopy. The effects of monomer concentrations on curing characteristics and mechanical properties were studied. It was found that the cure time and scorch time were increased with increasing monomer concentration whereas the torque max-min value was slightly decreased. It was also noted that the increase in the monomer concentration resulted in stiffer rubber with increased modulus and reduced elongation at break

Wear of rubbers and its control in conveyer belt system

Rubbers are polymer materials characterized by the ability of reversible deformation under influence of external deformation forces, described as a material with elastic properties. Rubbers include natural rubber, naturally occurring substance and synthetic rubber, artificially derived from petrochemical product. Products made from rubber have flexible and stable 3-dimensional chemical structure and the ability to stretch repeatedly of about twice the original length and return to original length. These materials are enormously used in conveyer belt system. Today, rubber materials are altered with approximately 60% synthetic polymers to achieve desired properties of final product. This chapter investigates the wear of different types of rubbers against ceramic liners which is the most realistic case in mining industries, where conveyor belts are used for ore transportation pulleys in conveyer belt system are coated with sacrificial liners of ceramics and rubbers to prolong the life of the conveyor system. However, such pulley liners are exposed to wear and even chemical reactions particularly in mining industries that are involved in transporting ores. The investigation will provide information on surface in terms of wear mechanism of rubber against ceramics, wear rate and appearance of wear surfaces.Dilip Thapa Masrangi, Hadinata Salim, F. Hakami, A. Pramanik, and A. K. Basa