Controlled reactive modification of polypropylene with maleic anhydride via solvent-free technique

Abstract

The effect of radical scavengers on the control of β-scission of polypropylene (PP) during the free-radical grafting with maleic anhydride (MAH) in melt was investigated. The main interest was the evaluation of the effective concentration of radical scavengers Irganox 1010 (IRN1010) and Irgafos 168 (IRF168) for better control of grafting process. For this purpose, radical grafting of non-stabilized PP was performed in order to describe specifically the effect of proposed additives with no effect of additives in commercial PP grades. For this purpose, the influence of the initial concentration of IRN1010 ([IRN1010]0) on the reaction course was predicted with respect to the change of kinetic parameters, thermal and rheological properties of PP-g-MAH. Obtained results showed that the efficiency of IRN1010 and IRF168 is not proportional to their concentration above critical level as evidenced by rheological properties of PP-g-MAH. Above that point, both the grafting efficiency and grafting rate decrease and thus the determination of effective cIRN1010 is the key for approaching controlled radical grafting of PP.