| Abstract: | In an effort to improve the utility and processing of PVC, additives like heat distortion modifiers and plasticizers are often added. While the economics of using PVC are highly favorable, they are limited in their dimensional stability at high temperatures. Blending with a component having better dimensional stability at higher temperatures is therefore investigated. In this paper, use of a styrenic copolymer, styrene acrylonitrile (SAN), and a substituted styrenic copolymer, alpha methyl styrene acrylonitrile (αMSAN), is studied. The glass transition-composition behavior is studied through dynamic mechanical measurements. Heat distortion test results of the blend in compositions of 0–100 in 10% increments indicate enhanced DTUL above certain compositions. Rheological characterization is done both in the low strain steady shear and dynamic mode. High shear rate testing was done. In general it was found that while the styrenic copolymer exhibits a plasticization of the PVC glass transition, the substituted styrene, by maximizing the repulsive interaction effects, pushes the system to a limited partial miscibility. |
