Grafting of poly (methyl methacrylate) to granular corn starch

Abstract

Graft copolymers were prepared by the radical‐initiated polymerization of methyl methacrylate in aqueous slurries of granular corn starch. High conversions of monomer were realized, giving products which were readily recovered by filtration. The products were free‐flowing, white powders, which by microscopic examination looked much like granular starch. Grafting was demonstrated by extracting the granular products with ethylene dichloride, which in most instances removed only a minor part of the poly(methyl methacrylate). When azoisobutyronitrile was used for initiation, a high conversion of monomer resulted, but about 90% of the polymer was extractable with ethylene dichloride. Further evidence for grafting was obtained by extraction of predissolved product, prepared by dissolving the granular product in dimethyl sulfoxide, to destroy the structure of the starch granules, and precipitating with alcohol. The fractions soluble in ethylene dichloride contained significant amounts of carbohydrate. Similar treatment of product prepared with azoisobutyronitrile initiation or of physical blends of starch and poly(methyl methacrylate) gave much more efficient separation of starch from PMMA. Failure to obtain grafting with AIBN initiation suggests that grafting occurs mainly as a result of attack on starch by radicals generated by the reaction of hydrogen peroxide or organic hydroperoxide with ferrous iron. Acid hydrolysis of the products removed the starch. The PMMA so recovered typically had viscosity‐average molecular weights of the order of 106, which suggests the grafts contained very long branch chains of PMMA attached at very infrequent intervals.

Grafting of 2-(Dimethylamino)ethyl Methacrylate onto Potato Starch Using Potassium Permanganate/Sulfuric Acid Initiation System

“…Nowadays, various monomers have been used to modify the properties of starch by graft copolymerization using radiation [1] or photolysis [2], or in the presence of metallic ions [3][4][5][6][7][8][9][10][11][12][13][14], peroxides [15,16] or persulfate [17]. It was and still is the subject of numerous publications.…”

Polymer/Palyols, a New Class of Polyurethane Intermediates

“…Examples of cellulose graft copolymers are reported by Kulkarni and Mehta (9), Epstein and Ben-Nun ( 10 ) , and by Tim, Zhui, and Rogovin (11). Brockway and Moser observed an &dquo;initiator effect&dquo; when they grafted methyl methacrylate to corn starch (12). Examples of poly (vinyl alcohol) graft copolymers and fibers made therefrom are found in the patent literature (13,14,15,16).…”

Recent progress in chemical modification of starch and its applications

“…68 Starch gra copolymers have great market prospects as occulants but the lower graing efficiency is a big problem, which is badly in need of a solution. 68 Starch gra copolymers have great market prospects as occulants but the lower graing efficiency is a big problem, which is badly in need of a solution.…”

“…The possible mechanism of the graft copolymerization in Fe 2+ / H 2 O 2 redox system 68. The possible mechanism of the graft copolymerization in Fe 2+ / H 2 O 2 redox system 68.…”