Reactive grafting of glycidyl methacrylate onto polypropylene

Abstract

This work explored the melt-phase grafting of glycidyl methacrylate (GMA) onto polypropylene on a closely intermeshing corotating twin-screw extruder (16-mm screws, 40 : 1 length/diameter ratio). The modification of the base polypropylene to produce GMA-grafted polypropylene was achieved via peroxide-induced hydrogen abstraction from the polypropylene followed by the grafting of the GMA monomer or by the grafting of styrene followed by copolymerization with the GMA. In this study, both the position and order of the reactant addition were investigated as a route to improving graft yields and reducing side reactions (degradation). For the peroxide-GMA system, adding GMA to the melt before the peroxide resulted in significant improvements in the graft levels because of the improved dispersion of GMA in the melt. The addition of a comonomer (styrene) was explored as a second route to improving the graft yield. Although the addition of the comonomer led to a considerable rise in the level of grafted GMA, altering the order of the reactant addition was not found to contribute to an increase in the grafted GMA levels. However, variable levels of grafted styrene were achieved, and this may play an important role in the development of grafted polymers to suit specific needs.

An investigation on the role of GMA grafting degree on the efficiency of PET/PP-g-GMA reactive blending: morphology and mechanical properties

“…Among reactive monomers grafted onto polyolefin backbone are maleic anhydride (MAH) [20,21], glycidyl methacrylate (GMA) [22][23][24], oxazolines, and isocyanates [25]. Previous studies elucidated that bifunctional GMA monomer shows more tendency towards PP chains with respect to MAH because of unsaturated groups in GMA, meanwhile an epoxy ring capable of being opened with hydroxyl, carbonyl, and amine functional groups [26,27].…”

“…Previous studies elucidated that bifunctional GMA monomer shows more tendency towards PP chains with respect to MAH because of unsaturated groups in GMA, meanwhile an epoxy ring capable of being opened with hydroxyl, carbonyl, and amine functional groups [26,27]. In other words, epoxy functional groups in the GMA chemical structure cerate bond with other functional groups such as hydroxyls, amines, and anhydrides, and assist in free-radical grafting reaction with their unsaturated groups [22,25]. From this perspective, thermoplastics polymers have widely been modified with GMA via melt free-radical grafting [28][29][30].…”

Multi functionalization of polypropylene with controlled degradation and its structure characterization

“…The grafting of various monomers onto iPP have been reported by a number of groups, including acrylic acid (AA), 1,2 maleic anhydrides (MAH), [3][4][5][6][7][8][9] alkanethiols, 10 BMA, 11 glycidyl methacrylate (GMA). [12][13][14][15][16][17] In recent years, GMA used as a functionalized monomer has been received more and more attention, GMA is a very interesting monomer because of its bifunctional character: a free-radical reactive double bond together with an epoxy group that can react with a number of other functional groups such as carboxyl, hydroxyl, anhydride, and amine end groups. The greatest advantage of grafted polymer based on GMA is due to the presence of epoxy functional group in the grafted side chain, which can serve as an effective adhesion promoter through chemical bonding and charge transfer interaction at the interphase.…”

Kinetic study on free radical grafting of polyethylene with acrylic acid by reactive extrusion

“…The most widespread method of introducing functionality into polyolefins by reactive extrusion involves free radical grafting . A major challenge in conducting grafting modifications is to devise process conditions to minimize or control side reactions while simultaneously maximize grafting yields …”