Rani, Joseph; Jayamma,Francis; George,K E(Pergamon Press Ltd, December 18, 1991)
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Abstract:
The effects of modifying blends of poly(vinyl chloride) (PVC) with linear low density
polyethylene (LLDPE) by means of acrylic acid, maleic anhydride, phenolic resins and p-phenylene
diamine were investigated. Modification by acrylic acid and maleic anhydride in the presence of dicumyl
peroxide was found to be the most useful procedure for improving the mechanical behaviour and adhesion
properties of the blend. The improvement was found to be due mainly to the grafting of the carboxylic
acid to the polymer chains; grafting was found to be more effective in LLDPE/PVC blends than in pure
LLDPE.
Ethylene-propylene-diene rubber (EPDM) and isobutylene-isoprene rubber (IIR) were
compounded, precured to a low degree, and then were blended with natural rubber (NR).
The compounding ingredients for NR were then added and the final curing was done. NR/
EPDM and NR/IIR blends, prepared using this method, were found to possess much
improved mechanical properties as compared to their conventional counterparts. The optimum
precuring crosslink density that has to be given to the EPDM and IIR phases has
been determined.
Blends of 50/50 natural rubber (NR) and styrene-butadiene rubber (SBR) are vulcanized using
several conventional and semi-EV systems. The cure characteristics and vulcanizate properties
are compared. The quantity and quality of crosslinks in each case are deciphered by chemical
probes to correlate them with the vulcanizate properties.
Rani, Joseph(Gordon and Breach Science Publishers, Inc., August 30, 1985)
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Abstract:
Blends of natural rubber (NR) with styrene-butadiene rubber (SBR), polybutadiene
rubber (BR), ethylene-propylene terpolymer (EPDM) and acrylonitrile-butadiene
rubber (NBR) were vulcanised using an efficient vulcanisation (EV) system and a
semi-EV system. Compatible blends show a definite pattern of curing whereas the
incompatible blends show no such pattern.