Pre-irradiation-Induced Grafting Of Acrylic Acid Onto Styrene And Butadiene Block Copolymers Powder

The SBR,SBS and SEBS were used as the major raw materials to graft Acrylic Acid by pre-irradiation-induced grafting, in water or alcohol. The grafted powder with various graft levels were characterized and analyzed. Then, SEBS-g-AA applied in EVA and Al(OH)3blend system as compatilizer.(1) Functional monomer AAc was grafted onto SB powder successfully via pre-irradiation method in aqueous solution. The degree of grafting is considerably affected by temperature, time, concentration, and absorbed dose. Reaction rate tended to decrease, when temperature beyond85℃; The degree of grafting increased with reaction time until3h, and then reached a plateau; Grafting became saturated when the concentration exceeded50v%; Function of absorbed dose indicated that degree of grafting is highest at20kGy. FTIR and SEM results proved that AAc was grafted onto SB powder successfully. AAc grafted onto the SB powder enhances the thermal stability. The crystallinity of grafting products obviously increases with the increase in grafting degree at absorbed dose of10kGy.(2) Acrylic acid was grafted onto SBS powder using pre-irradiation method to produce SBS-g-PAA. The effects of monomer concentration, absorbed dose, reaction time and temperature on degree of grafting were discussed in detail.The optimum conditions in aqueous solution were7h,90℃,50v%,and50kGy.The FTIR Spectra of SBS-g-PAA proved that the polyacrylic acid have been grafted onto SBS powder successfully. Moreover, the thermogravimetry, X-ray diffraction and the scanning electron microscope were also studied. Compared with pristine SBS powder, the SBS-g-PAA powder analysis indicated that the thermal degradation exhibited a two-step degradation pattern, the crystallinity declined and the surface becomed smoother because of the introduction of polyacrylic acid.(3) Acrylic acid was grafted onto SEBS powder using pre-irradiation method to produce SEBS-g-PAA in alcohol. The optimum conditions were5h,80℃,40v%,and60kGy.The FTIR and XPS Spectras of SEBS-g-PAA proved that the polyacrylic acid have been grafted onto SEBS powder successfully. Moreover, the thermogravimetry, microscope were used to analyze pristine SEBS and SBS-g-PAA powder. The morphological analysis indicated that the polar monomer AAc enhanced microphase separation of SEBS.(4)The SEBS-g-AA and SEBS applied in EVA and Al(OH)3blend system as compatilizer. The results show that SEBS-g-AA was superior to SEBS as compatilizer in Tensile Strength, Elongation and Rheological property when low addition.