Acrylamide grafting

Acrylamide graft copolymers such as those with starch (qv)(131), dextran (132), and lignin (qv) (133), have been studied to try to reduce copolymer costs. A general disadvantage of acrylamide copolymers is greater cost compared to partially hydroly2ed polyacrylamides. 

Cotton linters and viscose grade wood pulp were partially xanthated under different conditions to study the effect of the degree of substitution on the acrylamide grafting of these pulps. Sodium hydroxide solutions of 2%, 4%, and 6% were used and the vapor phase xantha-tion process was applied for 0.5, 1.0, 1.5, and 2.0 h for... 

Cotton linters and viscose grade wood pulp were partially acetylated and carboxymethylated. The samples were grafted under the same conditions with acrylamide. Grafting yield and efficiency depend on several factors, such as the kind of pulp, chemical and physical structure, type of the introduced substituent, and degree of substitution (DS). 

Acrylamide-based products, in paper manufacture, 18 115 Acrylamide copolymers, functional monomers used in, 11 628 Acrylamide gels, 1 680 Acrylamide graft copolymers, 18 625 Acrylamide polymers, 1 292, 304-333. 

Sealing tape has 35 to 90 pounds per ream of kraft paper as a substrate, whereas, reinforced sealing tape is based on a bonded laminate of kraft paper, reinforcing fibers, and kraft paper. The adhesives applied to these substrates may be thin-boiling, waxy starches alone, or blended with a soluble dextrin (5). More recently, blends of a soluble dextrin with oxidized potato or a hydrox-ypropyl ether of an oxidized potato starch are being used (9). Also, the acetate or succinate of an oxidized waxy starch may be used (15) as well as specially produced waxy starch acrylamide graft copolymer products (16). 

An alternative to the acrylamide-based composite hydrogel dressing is an acrylamide grafted to a polyurethane film to give a transparent, flexible gel with an equilibrium water content of approximately 50 /o. The hydrated gel has a low modulus of elasticity and a high water permeability that facilitates the adherence of the gel to the wound surface. The permeability... 

Figure 6.3. Acrylamide grafting on the 12-hydroxy stearate previously reacted with the surface of BaS04. ...

The influence of charged acrylamide graft copolymers on the flocculation process of 5% (w/w) kaolin suspensions were investigated by Serita and Murai [17]. The flocculation ability of different copolymers was linked to their structure by measuring the sedimentation potential. An iep of kaolin particles was observed for the concentration of approximately 20 ppm polymer, and they could additionally show that copolymers were more effective for flocculation than typical commercial flocculants. 

Figure 6.11 Proposed mechanism for the HRP-initiated poly(acrylamide)-grafting of starch [39].

Material Preparation and Characterization. The effect of cupric ion on acrylamide graft level, as determined in an experiment separate from the tubing preparation, is shown in Figure 3. Based on this result, a cupric nitrate concentration of 0.01M in the solvent was chosen. 

SEMs were used to compare, in a qualitative sense, the surface texture of the acrvlamide-grafted Silastic and the ungrafted Silastic. Similar surface textures were noted in both cases (Figure 5). Because the acrylamide graft was dehydrated for SEM analysis, the graft also was observed in a hydrated... 

Figure 3. Effect of Cu2 concentration on acrylamide grafting to 10-mil Silastic (0.375 Mrad).

Table I. ESCA Elemental Ratios for Silastic and Acrylamide-Grafted...

Various modified forms of Cassia tora seed gum (e.g. carbamoylethyl Cassia tora gum (CB-CTG), cyanoethyl Cassia tora gum (CE-CTG), carboxymethyl Cassia tora gum (CM-CTG), quatemized Cassia tora gum (Q-CTG), acrylamide grafted Cassia tora gum (CTG-g-AA), and acrylonitrile grafted Cassia tora gum (CTG-g-AN) [79-85] have been tested against kaolin under laboratory conditions vis-a-vis poly(acrylamide) based synthetic flocculants. 

L12 Liu, R., DeLeonardis, P., Cellesi, F., Tirelli, N., and Saunders, B.R., Cationic temperature-responsive poly(A/-isopropyl acrylamide) graft copolymers From triggered association to gelation, Langmuir, 24, 7099,2008. 

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. 

Singh, A.V. Nath, L.K. Evaluation of acrylamide grafted moth bean starch as controlled release excipient. Carbohydr. Polym. 2012, 87 (4), 2677-2682. 

Ultrafine inorganic parti- Acrylic acid, acrylamide, Grafted materials give [104]... 

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