Unit I
Structure-property relationships in rubbers: structure and rubber elasticity, effect of structure onTg, influence of chemical structure on thermal, mechanical and chemical properties. General Purpose Elastomeric materials ─ Manufacture, structure, properties and applications of Natural rubber (NR), chemically modified NR, Butyl rubber (BR) Styrene butadiene rubber (SBR), poly isoprene rubber (IR), polybutadiene rubber (BR), Butyl Rubber (IIR)
Unit II
Special purpose rubbers: Manufacture, structure, properties and applications of nitrile rubber, Neoprene rubber, EPDM, silicone rubber, Fluorocarbon rubber, polysulphide rubbers, EVA, polyurethanes, thermoplastic elastomers and Ionomers.
Rubber Compounding and Vulcanisation –vulcanizing agents, accelerators, activators, antioxidants, antiozonants, blowing agents, flame retardants, plasticisers, fillers and other additives. General compound design. Reinforcement: principle of reinforcement, filler properties-particle size, surface area and filler structure. Rubber vulcanization: sulphur and non-sulphur systems, assessment of state of cure.
Unit III
Rubber Processing – Machinery used for mixing: two roll mill, internal mixers and continuous mixers, extrusion technology, calendering, fabric coating and spreading process. Moulding techniques – Compression, transfer and injection moulding. Vulcanisation methods: rotocure, autoclave open steam, hot air, fluidised bed, high energy radiation curing.
Case studies on formulation and processing of dry and latex rubber products