Abstract: The performance of alkali lignin filling natural rubber was studied. The characteristic of network structure of filler in rubber compound and its influence on dynamic mechanical properties were investigated. The vulcanizate was observed and analyzed by scanning electron microscopy(SEM),mechanical properties and dynamic mechanical properties test. The results showed that there was almost no filler-filler interactions in alkali lignin filled vulcanizate,the rubber-filler interactions was very weak,and the alkali lignin particles agglomerated when the filling amounts of alkali lignin were 10%-50%. The mechanical properties of vulcanizate were not decreased largely after filling alkali lignin. The tensile strength of 10% alkali lignin filled vulcanizate was 30MPa,higher than that of no alkali lignin filled sample(28.7MPa). The filling of alkali lignin partly accelerated the vulcanization of rubber. The crosslinking density was increased with the addition of alkali lignin and it decreased when the filling amount of alkali lignin was 50%,with the tensile strength of 20.1MPa. The aging resistance was improved with the increase of the amount of alkali lignin. And there was no obvious impact on the vulcanizate's wet skid resistance and rolling resistance with the filling of alkali lignin.

Key words: alkali lignin, natural rubber, Payne effect, mechanical properties