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

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. •Reactive modification of non-stabilized PP with MAH via solvent-free radical grafting in melt.•Application of primary antioxidant Irganox 1010 to prevent PP degradation during reaction.•Online monitoring of radical grafting of PP using rheology instruments and characterization of PP-g-MAH.•Description of the effect of Irganox 1010 on the controlled PP grafting and prevention of PP against β-scission.•Determination of effective concentration of Irganox 1010.