Acrylamide Graft Copolymerization

Amylopectins. — The effects of acrylamide graft copolymerization on the solution properties of amylopectin have been discussed. Amylopectin has been dyed with DyAmyl-L and used in this form as a substrate for the assay of a-amylase. Amylopectin has been treated with isocyanate derivatives of 4-amino-( 1,1-dimethyl ethyl)-3-(methylthio)-l,2,4-triazin-5(4/f)-one ( metribuzin ) or acid chloride derivatives of 2,4-dichlorophenoxyacetic acid ( 2,4-D ) and 2,2-dichloropropionic acid ( dalapon ), to produce controlled-release polymeric pesticide systems. The solvent system utilized for these reactions, a lithium chloride or bromide salt in AW-dimethylacetamide, allows dissolution of the reactant salt and facilitates analysis of the polymer product by such techniques as i.r., U.V., and n.m.r. spectroscopies and gel permeation chromatography. Derivatives of other naturally occurring polysaccharides, including amylopectin, cellulose, chitin, and dextran, were also prepared. 

Amylose. — The effects of acrylamide graft copolymerization on the solution properties of amyloses have been discussed. As part of a study of the blue... 

The effects of acrylamide graft copolymerization on the solution properties of dextran have been described. 

Qiu et al. [241 have reported the synthesis of macromolecules having 4-tolylureido pendant groups, such as poly(N-acryloyl-N -4-tolylurea-cvi ethyl acrylate) [po-ly(ATU-co-EA)] 18, and poly(N-methacryloyl-A/ -4-tol-ylurea-co-EA) [poly(MTU-co-EA)] 19, from the copolymerization of ATU and MTU with EA, respectively. Graft copolymerization of acrylamide onto the surface of these two copolymer films took place using the Ce(lV) ion as initiator. The graft copolymerization is proposed as Scheme (12). 

Fig. 5 Fluorescence micrograph of siuface photo-graft-copolymerized with (W-dimethyl-amino) propyl acrylamide methiodide (DMAPAAmMel) by UV irradiation through the stripe-patterned projection mask and the neutral-density filter and subsequently stained with rose bengal, and the three-dimensional image, b of the distribution of the florescence intensity in the area shown in a...

Fig. 11 Visualization of the sequential progress of branching stage by staining with rose bengal. DC-derivatized PST surface (GO) was graft-copolymerized with CMS and dimethylaminoethyl acrylamide (DMAEMA), and subsequent quarternization, while narrowing the irradiation area in each polymerization stage (item, GI item, GI+GII item, GI+GII- -GIII) by the combination of three kinds of masks with linear openings (line widths 2 mm for GI, 1 mm for GII, 0.5 mm for GUI). Bar=0.5 mm...

E.A. Abdel-Razik, Photoinduced graft copolymerization of acrylamide onto styrene-butadiene-acrylonitrile copolymer, J. Photocltem. Photobiol., A, 69(1) 121-124, October 1992. 

E, A. Abdel-Razik, Photoinduced graft copolymerization of acrylamide onto styrene-butadiene-acrylonitrile... 

M Suzuki and C. A. Wilkie, Graft copolymerization of methacrylic acid and acrylamide onto acrylonitrile-... 

T.M. Aminabhavi, H.G. Naik, Synthesis of graft copolymeric membranes of poly(vinyl alcohol) and poly(acrylamide) for the pervaporation separation of water/acetic acid mixtures, J. Appl. Polym. Sci. 83 (2002) 244-258. 

Base polymer Starch—graft copolymerization, carboxymethylation Cellulose—graft copolymerization, carboxymethylation Synthetic polymers—poly(acrylate), poly(vinyl alcohol), poly(acrylamide), poly(oxyethylene), cationic polymer... 

Different types of chemical initiators such as FAS-KPS, benzoyl peroxide, azo-bis-iso-butylnitrile, H O, ascorbic acid-KPS, ammonium persulphate, ceric ammonium persulphate, ceric ammonium nitrate, etc., can be used for the graft copolymerization of various vinyl monomers such as methylacrylate, methyl methacrylate, acrylic acid, methacrylic acid, ethyl methacrylate, vinyl acetate, acrylamide, etc., onto polysaccharides [38-40]. Figure 2.1 shows the proposed mechanism through which the grafting can be explained [39]. 

Microwave-assisted synthesis of a guar-g-polyactylamide (G-g-PAA) has also been reported [80]. The reactions were performed in a domestic microwave oven. Graft copolymerization of the guar gum (GG) with acrylamide (AA) under the action of microwave irradiation in the absence of any radical initiators and catalyst resulted in grafting yields comparable with redox (potassium persulfate-ascorbic acid) initiated by conventional heating but in a very short reaction time. Grafting efficiency up to 20% was further increased when initiators and catalyst were used under microwave irradiation conditions. Maximum grafting efficiency achieved under MW conditions was 66.66% in 0.22 min, compared with 49.12% in 90 min by the conventional method. 

Synthesis and graft copolymerization of poly(diallyl dimethylammonium chloride) with acrylamide [127],... 

Lightly cross-linked polyacrylamide is used to make superabsorbents of water. Astarch-g-polyacryla-mide/clay superabsorbent composite has been synthesized [27] by graft copolymerization reaction of acrylamide, potato starch, and kaolinite micropowder (< 1 pm) followed by hydrolysis with sodium hydroxide. Such a superabsorbent of compositin 20% kaolinite, 20% potato starch, 60% acrylamide, 2% initiator (ceric amonium nitrate), and 0.04% cross-linker (N,N-methylenebisacrylamide) is found to absorb 2250 g H20/g at room temperature at swelling equilibrium. 

---