Grafting of glycidyl methacrylate onto polypropylene using supercritical carbon dioxide

• Published in: European polymer journal Vol. 41; no. 9; pp. 2176 - 2182
• Main Authors: Kunita, M.H., Rinaldi, A.W., Girotto, E.M., Radovanovic, E., Muniz, E.C., Rubira, A.F.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2005; Elsevier
• Subjects: Applied sciences; Copolymerization; Exact sciences and technology; Glycidyl methacrylate; Graft copolymers; Organic polymers; Physicochemistry of polymers; Polypropylene (PP); Preparation, kinetics, thermodynamics, mechanism and catalysts; Radical polymerisation; Supercritical carbon dioxide; Glycidyl methacrylate; Radical polymerisation; Graft copolymers; Supercritical carbon dioxide; Polypropylene (PP); Propylene copolymer; Crystal form; Graft copolymer; Film; Pressure impregnating; Propylene polymer; Carbon dioxide; Crystallinity; Surface topography; Experimental study; Grafting; Glycidyl methacrylate copolymer; Preparation; Supercritical solvent; Liquid solid reaction; Chemical reactivity; Heterogeneous reaction
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2005.04.004

Free-radical grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) films has been studied using supercritical carbon dioxide (SC-CO
2) as a solvent and a swelling agent. As the reaction temperature was below the melting point, PP was modified in the solid phase. The PP film was first soaked with the monomer GMA and benzoyl peroxide (BPO) as an initiator using SC-CO
2 at different experimental conditions of pressure, temperature, and thermal treatment time. After releasing CO
2, film GMA molecules were grafted onto PP in different times. Using this method, the degree of grafting and the morphology could be controlled through the combination of pressure, temperature, and soaking time. FTIR spectra confirmed that GMA had been grafted onto PP and that polypropylene-graft-glycidyl methacrylate (PP-g-GMA) presented a high surface reactivity for conductive polyaniline anchoring. DSC measurements and TG analyses showed that the thermal profiles of the graft copolymer and virgin PP are quite similar and that the graft PP does not exhibit changes in terms of thermal degradation profile and melting temperature, respectively. X-ray data showed that a high degree of grafting leads to a lower degree of crystallinity of polypropylene.