EFFECTS OF TEMPERATURE, STRAIN RATE, AND SWELLING ON THE STRESS-STRAIN PROPERTIES OF STYRENEBUTADIENE GUM VULCANIZATES OF VARYING CROSS-LINK DENSITIES,
Abstract
THE STRESS-STRAIN PROPERTIES AND ULTIMATE PROPER TIES OF SBR gum vulcanizates of varying crosslink density (swollen and unswollen) were determined at two temperatures and two strain rates. The polymer/solvent interaction parameter for the system SBR-benzene at 25 C was determined as a function of cross-link density. The network structural parameters obtained from swollen measurements were 30 to 40% lower than values obtained from unswollen measurements at high temperatures. The Mooney-Rivlin constants were found to depend on temperature, strain rate, and cross-link density. The constant 2C sub 1 could not be used in the statistical theory equation as the network structural parameter to predict the equilibrium behavior of unswollen vulcanizates. Thermoelastic measurements confirmed that SBR undergoes a negative internal energy change on extension due to rotational energy levels within the chains; however, this did not decrease the Mooney-Rivlin C sub 2 term. The ultimate properties (swollen and unswollen), when plotted as log (sigma sub B/G) versus log alpha sub B, described in a single curve that was independent of time and temperature as was found by Landel and Fedors. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 02, 1963
- Accession Number
- AD0414975
Entities
People
- T. J. Dudek
Organizations
- The Aerospace Corporation