The Study Of Low Styrene Butadiene And Styrene Copolymer' Synthesize And Microstructure

Organ lithium is an important initiator of diene living polymerization. It synthesize many good performance rubber, such as LCBR,SSBR and SBS. The microstructure of polybutadiene sequence has great effect on the mechanism properties. In this paper, polymerization conversion, molecular weight, microstructure and gel content were studied in the ultrasonic field.The polymerization conversion is little effected by the ultrasonic under high temperature .But under the low temperature, especially in the low conversion case, the effect is more notability. The ultrasonic degrade macro molecule, low the Mooney viscosity of polymer, better process property .The mechanism property testing of cured rubber show that it has the same tensile strength and tear strength, as polymerization without ultrasonic. The effect of ultrasonic on the copolymer's micro structure is lowed the 1,4-PB content and the random polystyrene ,the ratio of cis-PB and trans-PB is increase at first, but decrease at the point that 2G/Li~+=0.8.The gel content is decreased in the ultrasonic field.The acetyl acetone is added to the anionically polymerized polybutadiene .We found it can increase the polymerization rate with a small content (acac/Li~+=0.2). The analyses of polymer's ~1H-NMR show that, the polymer' microstructure is not changed by acetyl acetone adding. The 1, 2-PB content is still 8~9% with the acac/Li~+ rang from 0.01 to 20. The adding of acetyl acetone only increases the polymerization rate, but not good polar compounds.