Preparation And Applications Of Epoxidized Styrene-Butadiene-Styrene Block Polymer (SBS)

The modification of styrene-butadiene-styrene block polymer (SBS) was completed by its epoxidation in situ. Then, the asphalt was modified by epoxidized SBS.It was shown by IR spectroscopy that epoxidized groups were existed in the modified SBS, because the absorption peak of oxirane at about 1250 cm-1 was found. In addition, the absorption peak of carbonyl group at about 1700~1740 cm-1 and that of hydroxyl group at about 3500 cm-1 were found. So the side reaction of epoxidation in this work took place. It is deduced that the extent of side reaction increased with increasing reaction time. The optimal conditions for epoxidation of SBS are as following: reactive temperature 70C, reactive time 3h, concentration of SBS 100g /L, and formic acid/hydrogen peroxide(v/v)l:2.5. The epoxy group content of the product was about 12.7%. Some basic properties of epoxidized SBS were measured, including intrinsic viscosity, tensile property, oil-proofness and heat resistance. Intrinsic viscosity of epoxidized SBS was greater than that of SBS, and it was linearly dependent on the mass fraction of epoxidized SBS. Oil-proofness of epoxidized SBS increased with increasing the mass fraction of epoxidized SBS in the same oil. It was found that the difference between the heat resistance of epoxidized SBS and that of SBS was not obviously distinct.The other fundamental properties (penetration, softening point, ductility) of the modified asphalt and modified mechanism were studied also. The results indicated that the properties of the modified asphalt were influenced bycharacteristics, content and the mass fraction of epoxidized SBS and reactive time. The performance of Kraton epoxidized SBS modified asphalt was better that of Yuehua epoxidized SBS modified asphalt. The mass fraction of epoxidized SBS affected ductility of modified asphalt, i.e. its ductility was rapidly decreased with increasing the mass fraction of epoxidized SBS. It was found that the content of epoxidized SBS was 6% and reactive time was five hours. The viscosity of modified asphalt was increased with increasing the content and the mass fraction of epoxidized SBS, and it was decreased with increasing reactive time.The production process of epoxidized SBS modified asphalt was simple, and its large-scale application to commercial production was probable based on this work.