Original scientific paper

Free Radical Grafting of Methyl Methacrylate onto Ethylene-Propylene Amorphous Copolymer

Ljubica Tomašek ; Faculty of Chemical Engineering and Technology, University of Zagreb Marulićev trg 19, HR-10000 Zagreb, Croatia
Ante Jukić ; Faculty of Chemical Engineering and Technology, University of Zagreb Marulićev trg 19, HR-10000 Zagreb, Croatia
Zvonimir Janović ; Faculty of Chemical Engineering and Technology, University of Zagreb Marulićev trg 19, HR-10000 Zagreb, Croatia

Abstract

This study investigated the free radical graft copolymerization of methyl methacrylate (MMA) onto amorphous poly(ethylene-co-propylene) (EPC) in toluene solution, when using benzoyl peroxide
(BPO) and 2,2´-azobisizobutyronitrile (AIBN) initiators over a wide composition and temperature range. Graft copolymer formation was verified by selective solvent extraction, infrared spectroscopy, and the turbidimetric titration method. Besides graft copolymerization, the homopolymerization reaction of vinyl monomer takes place as well. It was found that grafting is more efficiently induced by BPO, as compared to AIBN. The grafting efficiency (GE) decreased with increasing polymerization temperature and, more significantly, with the increasing MMA concentration. The GE steadily decreased from 90 % to about 30 % over a two hours reaction period at 90 °C reaction temperature, in response to increasing MMA concentration from 0.2 to 1.8 mol dm–3 at a constant EPC concentration of 60 g dm–3. A reaction temperature increase from 70 °C to 95 °C caused a decrease in GE from ~100 % to 75 %. The obtained graft copolymers were characterized for molecular weight distribution and viscometric behavior in dilute xylene solutions and compared with corresponding EPC/PMMA physical mixtures.

Keywords

graft copolymerization; poly(ethylene-co-propylene); methyl methacrylate; solution; viscosity

Hrčak ID:

45629

URI

https://hrcak.srce.hr/45629

Publication date:

20.12.2009.

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