Ultrasonic Degradation and Block Copolymerization of Polybutadiene with Acrylic Acid

The ultrasonic degradation of polybutadiene (PB) and block copolymerization of PB with acrylic acid (AA) in cyclohexane solution were studied. The results show that the chain-scission reaction of PB follows the equation M(t)BAR = (M0BAR - M(infinity)BAR)e(-kt) + M(infinity)BAR, where k = 33.33 X 10(-5) s-1. The structure of the copolymer was identified by IR and NMR, and is a block one. The mechanism of the coupling effect of the copolymer (PB-b-AA) prepared in the CaCO3/SBR system was also studied by means of SEM and IR. The surface properties of CaCO3 treated with the copolymer and the morphology of the fracture surface of vulcanized SBR/CaCO3 were examined. The compatibility and mechanical properties of the SBR/CaCO3 system greatly improved.