Evaluation of coring and physical properties of elastomeric blends

摘要

Natural rubber(NR)posseses good mechanical properties such as high tensile and tear strengths due to its ability to crystallize upon stretching.The elasticity and dynamic properties of NR are also excellent,However,due to the existence of numerous reactive double bonds on the molecular backbone,NR is highly susceptible to degradation by thermal aging and ozone attack.In addition,oil resistance of NR is relatively poor,compared to some polar synthetic rubbers such as chloroprene rubber(CR)or acrylonitrilebutadiene rubber(NBR).To overcome such shortcomings,NR is frequently blended with synthetic rubbers such as NBR or CR.Recently,blends of NR/CR have been extensively studied.Filler plays important role in the performance of blend.In Natural-Neoprene rubber blend silica was selected as reinforcing filler due to its unique characteristics such as good interaction with CR & better filler dispersion and greater cross link density.This paper also investigates the effect of blend ratio along with effect of surface treated filler on the properties of compound.Mechanical properties is increased because surface treated filler are more easily diffused without agglomerate in the polymer network compared to unmodified filler,silica filled CR possesses lower compound viscosity and better mechanical properties,compared to silica filled NR.The presence of more reactive double bond,make it more susceptible to degradation.So attention was also given to the increase the resistance to thermal aging,oil and ozone resistance of the blends.The aging properties i.e oil and ozone resistance of the silica-filled CR are also significantly better than those of the silica-filled NR.The overall properties of natural rubber are modified by presence of CR remains the matrix in the blend.