Free radical mechanism for reactive processing of polymers in the presence of organoclay/peroxide nanoreactors: Grafting maleic anhydride onto polypropylene

[Display omitted] •Real nanoreactor must have o-MMT/DCP mass ratio >4:1.•Succinic groups with different lengths are grafted onto PP-graft-MA.•Succinic groups are grafted preferentially to PP end chains.•The presence of o-MMT induces secondary PP macroradicals recombination.•Presence of o-MMT induces MA hompolymerization. PP-graft-MA is a common PP compatibilizer, produced via reactive extrusion using peroxides as initiator, which causes severe molar mass reduction. To control PP degradation and increase maleic anhydride grafting, Shi and coworkers (2006), proposed the use of nanoreactors. In this paper we propose a complete new reactive mechanism involving nanoreactors during PP-graft-MA reactive processing. The samples were prepared via melt mixing using nanoreactors with different organoclay: peroxide ratios (oMMT:DCP). Organic MMT showed to absorb not more than 16 wt% of DCP, i.e., diffusional controlled release of alkoxy radical will not be observed at o-MMT:DCP ratios