Rubber-Solvent Interaction Parameter (X_(1,2)) of NR/SBR Rubber Blend Solution In Determination of Crosslink Concentration for Vulcanized Rubber Blend

摘要

Crosslink concentration is an important property affecting the major characteristic of cured rubber. One of the important parameters to determine the crosslink concentration of a vulcanized rubber by swelling measurement is the rubber-solvent interaction parameter known as 'kai' value denoted as X. For single rubber, the X value is known however, the X_(1, 2) for rubber blends are unknown. This research is concerned with the investigation in determining the X_(1, 2) for rubber blends solution (uncured rubber). Natural rubber (NR) and styrene butadiene rubber (SBR) rubber blends solution were blended at 7 different ratios of 100/0, 80/20, 70/30, 60/40, 50/50, 40/60 and 0/100; and were dissolved in toluene. The X_(1, 2) values of each rubber blend were determined based on the intrinsic viscosity measurement. Crosslink concentrations of vulcanized rubber blends obtained from the swelling measurement were then compared against the value determined from simple extension measurement (stress-relaxation method). This cross-checking was to ensure the accuracy and reliability of X_(1, 2) value for rubber blends solution.