Butyl rubber IIR

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INTRODUCTION

Butyl rubber is a copolymer of Isobutylene with a small percentage of isoprene to provide curing sites for curing. Isobutylene was the first alkene to be polymerized.IIR has Unusually low resilience at room temperature for an elastomer with such a low Tg(-70°C)

The rubber has excellent aging stability, and another excellent feature is impermeable to gases.
Butyl rubber does not breakdown easily in milling.Thus in presence of a promotor like p- dinitroso benzene this rubber interacts with carbon black at Banbury mixer about 180°C and get better reinforcement this is called heat treatment of IIR.

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