Abstract: Thermal decomposition of PP-g-MAH was studied using a thermogravimetric analyzer and the effects of grafting ratio, βchain scission and maleic anhydride residue on the thermal stability of PP-g-MAH were investigated. The results indicated that the grafting of MAH improved the thermal stability of PP. Compared with the virgin PP, thermal decomposition temperature of PP-g-MAH with an MAH grafting ratio of 0.72 % increased by 28℃and its thermal decomposition rate constant at 420℃ decreased by 57.6%. Theβchain scission and degradation that occurred during the melt grafting process injured thermal stability of the resulting PP-g-MAH. By contrast with minimum degradation of the graft, thermal decomposition temperature of maximum one decreased by 20℃and its thermal decomposition rate constant at 420℃ increased by 115 %. Maleic anhydride remaining in the grafted PP make the initial decomposition temperature 4.3℃ lower.

Key words: polypropylene-graft-maleic anhydride, thermal stability, thermal degradation