Peroxide prevulcanisation of natural rubber latex with t-butyl hydroperoxide
1993
Davies, R.T. | Gazeley, K.F. (Malaysian Rubber Producers' Research Association, Brickendonbury, Hertford (United Kingdom))
A peroxide prevulcanisation method involving t-butyl hydroperoxide (tBHP) with fructose as an activator has been studied in detail for its suitability for commercial application. The effects of prevulcanisation temperature, concentration of tBHP, fructose/tBHP ratio and intrinsic iron content on the rate and extent of prevulcanisation have been investigated. Addition of the tBHP in several stages throughout the prevulcanisation, instead of one aliquot at the start, improves the overall crosslinking efficiency. Peroxide prevulcanised latex (PPVL) can be used in conventional coagulant dipping and heat-sensitive dipping processes to produce films with similar unaged properties to those of films made from a low modulus sulphur prevulcanisate. Babies' bottle teats which pass the British Standard requirements for physical properties have been made from PPVL. Unleached PPVL film shows good resistance to heat-ageing but leached film requires an added antioxidant. A mixture of Polygard [tris (mixed mono- and di-nonylphenyl) phosphite] and 2246 [2,2'-methylene-bis-(4-ethyl-6-6-t-butylphenol)] confers good ageing resistance on PPVL films and does not introduce nitrosamines or nitrosatable amines
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