Maleic anhydride grafting of propylene-ethylene copolymers. Effect of molecular structure

VERÓNICA RIECHERT; ANIBAL FERROFINO; MARCELO DANIEL FAILLA; LIDIA MARÍA QUINZANI

Capital Federal

Simposio; XIII Simposio Argentino de Polímeros; 2019

Universidad Tecnológica Nacional

Random propylene-ethylene copolymers with low ethylenecontent (PEC) are of great interest due to their higher impact resistance andlower softening temperature than polypropylene (PP).  In this study, PECs are functionalized withmaleic anhydride (MA) by reactive mixing (PECg), and the effect of ethylenecontent and average molecular weight on the effectiveness of scission andgrafting reactions are investigated. The main result is that the ethylene unitspresent in PECs favor chain-linking reactions and/or hinder molecular scissionduring grafting with MA in the presence of organic peroxide(2,5-dimethyl-2,5-di(tert-butyl peroxy) hexane; DBPH). Moreover, the amount ofAGs grafted per average molecule increases with ethylene content for a givennumber average molecular weight, which means that the presence ofirregularities in the isotactic sequence of propane units of a PP backbonefavor the incorporation of AG.