Abstract: DSC, SALS, SAXS, WAXD and polarizing microscopy were used to study the crystalline structrures, equilibrium melting point and crystallization kineties of LLDPE in LLDPE/SBR blends. Its unit cell parameters, crystallite size, spherulite size and crystallinity remain unchanged when LLDPE content is above 50%. Crystallite and spherulite size dec-rease when LLDPE content is less than 50%. The long period of LLDPE ctystallites in theblends of various compositions is larger than that of pure LLDPE and increases with increasing SBR content. This system does not show melting point depression but gives higher chain folding free energy than pure LLDPE. Based on the above experimental observations it is concluded that in this system LLDPE and SBR are not compatible in general, but show certain extent of molecular chain mixing in the amorphous region of LLDPE.

Key words: Polyethylene, Styrene-butadiene rubber, LLDPE/SBR blend