The Structure of Gels. IX. Effects of Plasticizers on the Physical Properties of Styrene Butadiene Rubber

Abstract 1. The glass and flow temperatures and the strength and relative extension of rubber depend not only on the concentration of the plasticizer but also on its molecular structure. 2. Styrene butadiene rubber plasticized with nonpolar plasticizers has higher glass and flow transition temperatures than rubber plasticized with polar substances. The same relationships are found for the strength and relative extension of vulcanizates of this rubber. 3. Nonpolar plasticizers also weaken intramolecular interaction to a greater extent than polar plasticizers.