Hydrolyzed graft copolymers

Poly(starch-g-(l-amidoethylene)) copolymer is not a polyelectrolyte and will be a smaller molecule in water than an equal molecular weight, partially hydrolyzed poly(l-amidoethylene). Polyelectrolyte effect should, however, cause the graft copolymer to expand in solution in the same way it causes poly(l -amidoethylene) to expand, so a series of hydrolyzed graft copolymers were prepared from poly(starch-g-(l-amidoethylene))(41-43) and these derivatives were tested to determine the effect of hydrolysis on copolymer properties in solution. 

Weaver et al. [34] disclosed absorbent polymers prepared in a multi step process. First, a graft copolymer was formed from acrylonitrile and starch. The starch was gelatinized in hot water, followed by a complexation step with Ce + Then acrylonitrile was added to form the graft copolymer. The graft copolymer was isolated, and then saponified with a certain concentration of aqueous alkali such that a soluble, hydrolyzed graft copolymer was obtained. No alcohol was used in the hydrolysis step. Drying this polymer yielded a water Insoluble polymer that absorbed hundreds of times its dry weight in water. 

A hydrolyzed cereal soHd, predominately a hexasaccharide, is used in high pH lime muds for reducing the yield point and gel strength (67). This additive has been used in systems treated with both sodium hydroxide and potassium hydroxide in addition to other additives common to lime muds (68). A second viscosity-reducing additive used in lime muds is a graft copolymer of acryflc acid and calcium flgnosulfonate (69). Both of these materials are used at levels of 6—17 kg/m (2—6 lb /bbl). 

When P[(St-NHCOCH3)-g-AAM] was hydrolyzed in the basic solution no PAAM was released. The scanning electron microscopy (SEM) micrograph of the copolymer shows that the hydrolyzed grafted beads are still covered with PAAMs with salient micrographs. The results reveal that AAM graft copolymerization is initiated by the nitrogen radical rather than any other radical. 

Grafting of 2-methyloxazoline onto chloromethylated polystyrene beads in benzonitrile at 110 °C gave graft copolymers, which were hydrolyzed to poly(styrene-g-ethylenimine) and useful as a chelating resin370. ... 

The synthesis of PDMS macromonomers with vinyl silane end-groups and their free-radical copolymerization with vinyl acetate, leading to poly(vinyl acetate)-PDMS graft copolymers, was described 346). The copolymers produced were later hydrolyzed to obtain poly(vinyl alcohol)-PDMS graft copolymers. 

Hydrolysis. The starting material for the hydrolysis reaction is a 2.0 g sample of previously prepared, graft copolymer(41,42). The copolymer is hydrolyzed in a basic, saline, aqueous solution under anaerobic conditions. Sufficient copolymer is dissolved in sufficient sodium chloride brine to form a combined, final reaction mixture of 2 g/dL copolymer in 1.0 M sodium chloride. Sufficient sodium hydroxide is dissolved in water to yield a final concentration in the combined reaction mixture of 0.5 M. The solutions are saturated with nitrogen, warmed to 40°C, combined, and allowed to react with stirring for 10 minutes under a nitrogen blanket. 

Results and Discussion. Of the 12 samples of starch graft copolymer synthesized, half were hydrolyzed to anionic polyelectrolytes. Synthesis data on these 6 samples are given in Table 2. These particular samples were chosen for hydrolysis because the samples can be intercompared to see the effect of synthesis variables on ultimate product properties. Samples 5, 8, and 11 have the same mole ratio of cerium ion to starch backbone, N, in their reaction mixture. Samples 7, 8, and 9 all have the same refctable mass per starch molecule,... 

M, in their reaction mixtures. In general, as the mass fraction of hydrolyzable sidechain in the graft copolymer increases, the... 

ATRP and grafting from methods led to the synthesis of poly(styrene-g-tert-butyl acrylate)-fr-poly(ethylene-co-butylene)-fr-poly(styrene-g-ferf-butyl acrylate) block-graft copolymer [203]. ATRP initiating sites were produced along the PS blocks by chloromethylation as shown in Scheme 112. These sites then served to polymerize the ferf-butyl acrylate. The poly(ferf-butyl acrylate) grafts were hydrolyzed to result in the corresponding poly(acrylic... 

Molecular Weight of Grafted PAN Chains. A homopolymer-free graft copolymer sample was hydrolyzed in 2 M HC1 for 48 h at room temperature to depolymerize the cellulose chains. The residue, mainly polyacrylonitrile (PAN) chains, was washed with water and... 

Hydrolysis of starch graft polymers formed with vinyl acetate was reported to produce polyfvinyl alcohol)-grafted starches using oxidized starches.3021-3027 Hydrolysis of graft copolymer with 72% aqueous sulfuric acid and determination of glucose in the hydrolyzate by the Fehling reagent can be used.3028... 

An alternating copolymer of styrene and vinyl acetate can be turned into a graft copolymer by hydrolyzing it and then adding ethylene oxide. Draw the structure of the graft copolymer. 

---