Maleic anhydride grafted chemical structure

Due to its non-polar chemical structure, PP interacts poorly with the typically pwlar fillers such as CaC03, and optimum dispersion is normally difficult to achieve. Compatibilisers are frequently used to improve the interfacial adhesion between CaC03 and PP, in order to gain the envisaged enhancement in mechanical properties (Fuad et al, 2010). Bi-functional molecules such as maleic-anhydride grafted PP (PP-g-MAH) are commonly used as compatibilisers for PP and CaC03 (Roberts Constable, 2003). 

Figure 3.8 Chemical structure of maleic anhydride grafted PP (PPgMAH). (From Uniroyal Chemical Co., Inc., literature.)...

Solution or bulk functionalization of PO by unsaturated functional molecules is largely studied. In particular, maleic anhydride (MAH)-grafted polymers are widely used commercial products [4-7]. As in the case of halogenation, the mechanism is not clearly understood. Overall, MAH-grafting reactions are complicated. Reactions in an extruder are particularly difficult to predict. Several schemes of reactions and structures of the grafted polymers have been proposed [7-10]. The insertion of a MAH group into the backbone of PO has also been reported. A commercial product from BP Chemicals, Polybond , has been reported to be maleated selectively at the chain ends. Ionic crosslinked rubber-like polymers were obtained from the reaction of maleic anhydride-grafted PO with some alkali metal compounds [11]. 

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