.cpvc / Abs Structure And Performance

Chlorinated polyvinyl chloride (CPVC) is known for its excellent high temperature performance, along with other desirable physical properties. Due to its high glass transition temperature, high heat deflection temperature, outstanding flame and smoke properties and chemical inertness, CPVC has become a valuable engineer thermoplastic. However, the poor impact strength and difficulties in processing limited the use of CPVC.ABS is a common modifier with core-shell structures of which polybutadiene is the core and the poly (styrene-co-acrylonitrile) (SAN) grafted on the polybutadiene is the shell. The core-shell modifiers can regulate the interface interactions between rubber modifiers and the matrix. When blending with CPVC, it can greatly improve the thermal tendency and the impact strength. However, there were no explicit explications were given about the relationship between structure and properties in the modification of CPVC by modifiers. Our work mainly dealt with the relationships between the morphology and mechanical properties and the dynamic mechanical properties of the CPVC/ABS blends.1. The effect of AN content on compatibility of CPVC/SAN blends was a simplified model for the CPVC/ABS system. The AN content to the compatibility were studied. Dynamic mechanical analysis results of CPVC/SAN were in accordance with the morphological properties of CPVC/ABS. The mechanical properties of CPVC/ABS blends in which the PB content was set to 15wt% were studied. Results showed, with the change of AN content, the impact strength followed different way for CPVC/ABS blends with different core-shell ratios of ABS due to the influence of the compatibility. When the core-shell ratio was 40/60, the CPVC/ABS blends were much ductile in more widely AN range than the blends which the core-shell ratio of ABS was 70/30.The differences also showed in the SEM micrographs by the investigation of toughening mechanism.2. The effect of core-shell ratio of ABS on mechanical and structure properties of CPVC/ABS blends were studied. The results showed that the impact strength of the blends expressed first increase and then decrease with the increase of the core-shell ratio of ABS. When the core-shell ratio was 40/60, the blend showed a max value. While the tensile strength showed slightly increase. SEM showed that the blends of CPVC/ABS30-70 were incompatibility apparently. Dynamic mechanical analysis showed that the tan8 peak of SAN rich-phase partly overlapped with CPVC rich-phase as the increase of the core-shell ratio of ABS. As for 30/70 core-shell ratio of ABS, different heat resistant of CPVC with ABS may lead the SAN became viscous below the glass transition temperature of CPVC. One glass transition temperature may attribute to the higher value of tanδof SAN which overlapped with the peak of glass transition temperature of CPVC. However, the blend was immiscibility.3. The effects of TDDM (tert-dodecyl mercaptan) content on ABS in the CPVC/ABS blends were investigated. Mechanical and morphology properties together with the dynamic mechanical analysis of CPVC/ABS blends were studied. The results show that as the increase of the TDDM content, Izod impact strength first increase and then decrease, while the tensile strength and elongations of blends slightly decrease with the amount of TDDM. Studies of dynamic mechanical properties of the CPVC/ABS blends show that the increasing of the TDDM content can enhance the compatibility between CPVC and ABS. SEM shows that the TDDM content t could not obvious effect on the homogeneous dispersion of PB particles. While the lower impact strength of higher TDDM content indicates that compatibility is not the only requirement for maximizing toughness.