Interface Characteristics On The Mechanical Behavior Of Silicone Rubber

Composites are made up of matrix,reinforcing filler and interphase.The three parts become one through interphase and this will bring a complex effect,so the structure and property of interphase perform a key function to compostites.Silicone rubber is a kind of special rubber which take on outstanding capabilities,but which can achieve those capabilities only after reinforcement.As a result,interfacial interaction deserves to be studied in silicone rubber in particular.Chemical bond theory and soakage theory are the most mature theories about interphase. On account of that,some experiments were designed.The three kinds of composites were synthesized by means of high speed homogenizer which were pure MWNTs/silicone rubber, carboxylated MWNTs/silicone rubber and hydroxylate MWNTs/silicone rubber.The tensile strength,elongation and modulus of composites were all impoved largely when MWNTs were added in silicone rubber.The pure MWNTs reached the best effect in tensile stength and elongation and the carboxylated MWNTs achieved the better.The carboxylated MWNTs/silicone rubber gained the maximum in tensile modulus and which in hydroxylate MWNTs/silicone rubber was next.IR,XPS and DMA were utilized to research the interfacial interaction in composites, and the results showed that the sequence about interfacial interaction was carboxylated MWNTs/silicone rubber＞hydroxylate MWNTs/silicone rubber＞pure MWNTs/silicone rubber. As a result,the effect of reinforcing physical interfacial interaction was better than that of reinforcing chemical interfacial interaction and both of them were much better than pure sample.It was the same as variety of the tensile modulus.AFM was used in research of interphase morphology in silicone rubber composites. According to results in AFM,the best dispersion was found in pure MWNTs/silicone rubber and that in carboxylated MWNTs/silicone rubber was better than that in hydroxylate MWNTs/silicone rubber.It's the same as variety of the tensile strength and elongation.So we can concluded that the good dispersion results in the good tensile strength and elongation.The study on resistivity in three different silicone rubber showed that the resistivity could applied to scale the volume of interphase in pure MWNTs/silicone rubber and hydroxylate MWNTs/silicone rubber,but not to carboxylated MWNTs/silicone rubber which contains larger electronegative units.The results in carbon fiber/silicon rubber showed that the size of filler was smaller,the interfacial interaction was stronger and reinforcing was better.The results in nanopowder silicone rubber/silicone rubber proved that the dispersion of interphase was not the only crucial factors.Furthermore,experiential expressions were used to explain some phenomena and the conclusion of expressions indicated that the thicker interphase layer would represent the better mechanical property.