Nano Sio <sub> 2 </ Sub> / Pp Composites And Performance Research

Polypropylene owns much advantages such as simple compsite processing, cheap, easy to be shaping, and sythesized mrits. It is a widely utilized foundational resin in the field of modification of material's properity. However, there are disadvantages such as low ductility, easy of aging, and bad weather resisting properity. It is a hot point for researchers to strengthen the Polypropylene and develop its potentials. Recently, research for polypropylene doped with inorganic nanoparticles has been focused, and has been used preliminary. But the present technology is not enough to reach the ideal strengthen effects. In addition, It is not deep enough to study for the mechanism of nanoparticle doped polypropylene. Therefore, it is siginificent to investigate various properties related with inorganic nanoparticles doped polypropylene.In this research topic, surface modified nanosized inorganic nanoparticles of SiO₂ were dispersed into polypropylene matrix, mechanical and crystalline properties of PP/SiO₂ composite materials were analysized, the interface state of composite materials and their strengthen machanism were investigated, some important results were deduced:(1) nanosized SiO₂ particles is in amorphous state, the particle size is large and is exited in a phase of linear aggregate; there are large quantity of —OH.(2) Study of Marai acid anhydried grafted polypropylene indicate that: both of acid anhydried and soft segment are exited in polypropylene, thus the aim of interface consistency is reached.Polypropylene owns much advantages such as simple compsite processing, cheap, easy to be shaping, and sythesized mrits. It is a widely utilized foundational resin in the field of modification of material's properity. However, there are disadvantages such as low ductility, easy of aging, and bad weather resisting properity. It is a hot point for researchers to strengthen the Polypropylene and develop its potentials. Recently, research for polypropylene doped with inorganic nanoparticles has been focused, and has been used preliminary. But the present technology is not enough to reach the ideal strengthen effects. In addition, It is not deep enough to study for the mechanism of nanoparticle doped polypropylene. Therefore, it is siginificent to investigate various properties related with inorganic nanoparticles dopedpolypropylene.In this research topic, surface modified nanosized inorganic nanoparticles of SiCK were dispersed into polypropylene matrix, mechanical and crystalline properties of PP/SiO2 composite materials were analysized, the interface state of composite materials and their strengthen machanism were investigated, some important results were deduced:(1) nanosized SiO2 particles is in amorphous state, the particle size is large and is exited in a phase of linear aggregate; there are large quantity of —OH.(2) Study of Marai acid anhydried grafted polypropylene indicate that: both of acid anhydried and soft segment are exited in polypropylene, thus the aim of interface consistency is reached.(3) Through comparing various mechanical properties related with coupling agent modified nano SiCK particle doped polypropylene, both of two types of coupling agents modified SiCK particle function strengthen to polypropylene. Silane coupling agent modified SiO2 particle doped polypropylene is more effective for material strengthen than ester titanate coupling agent modified SiOu particle doped polypropylene.(4) The melting point of polypropylene is slightly influenced; SiO- particle give founction of heterogenious nucleation. With the increasing of SiO2 particle intent, its crystallizational temperature increase at first and then decrease, but high than that of pure polypropylene. The crystallization occurs at higher temperature, their crystalline rate is large, and the ball-shaped crystallite size is small, which is one of the reason for evalation of ductility of composite materials.(5) By analysis of the tension interface, large area of matrix yield and thin fibre bunch induced by tension are observed. They imply that the evalation of ductility of composite materials is induced by matrix yield and fibrelization. Study of punching interface confirm a triditional ductile rupture.(6) A simple mode of interface function is forwarded. It is concluded that the most promising character is the coations of interfacial grafting materals and nanosized SiO2 particles, as well as the cocrystallization of interfacial grafting materals and matrix resin of polypropylene.