Lignin as reinforcing filler in rubber compound

Lignin is a reinforcing filler with properties such as abundantannually renewable, low weight, high biological efficiency, and wide ecological adaptability. These properties are causedincreasing attention from researchers and become an alternative to carbon black in the rubber industry. in this paper, we try to briefly review the lignin. In this regard,initially, the chemical structure of lignin and its structuresareconsidered. it is obvious from the application and process point that this polymer has little tendency to spread in the rubber matrix due to polar functional group and so it will not appear as agglomeration in rubber compoundand thereforewon’t be as reinforcing filler. There have been studies in order to solve this problem and improved the reinforcing properties of lignin. These include modifying the mixing process, increasing the interfacial bonding strength between lignin and the rubber, formation of nano structure with lignin and use of hybrid technologies with other filler.Here some of these methods and the effects of lignin on its curing, mechanical and thermal properties are summarized.