ABSTRACT
The graft copolymerization of crylic acid [AA] onto styrene butadiene rubber [SBR] was carried out in toluene at 80 degree C, using benzoyl peroxide [BPO] as initiator. The synthesized styrene butadiene rubber-g-acrylic acid [SBR-g-AA] was characterized with Raman IR spectroscopy. A study was conducted on the use of SBR-g-AA in the ratio 10 phr for improving the homogeneity of styrene butadiene rubber / chloroprene rubber [SBR/CR] blend. The SBR-g-AA was incorporated into SBR/CR blend with different blend ratios. The homogeneity of such blends was examined with scanning electron microscopy [SEM], differential scanning calorimetry [DSC] and determination of the dielectric properties. The scanning electron micrographs illustrate improvement of the morphology of SBR/CR rubber blend as a result of the incorporation of SBR-g-AA onto that blend. In addition, the dielectric constant [permittivity] and the dielectric loss plots vs. the SBR/CR blend ratio show straight lines upon incorporation SBR-g-AA indicating and confirming the homogeneity of that blend. Physico-mechanical properties of the blend vulcanizates, in presence and absence of SBR-g-AA, were determined and their thermal stability were evaluated after accelerated thermal aging. The results reveal that SBR/CR [25/75] blend possesses the best thermal stability. Swelling behavior in toluene, in motor oil and in brake fluid of the blend vulcanizates was also assessed