Crosslinked with epichlorohydrin

Hercosett 125 (Hercules) reactive cationic polymer formed by condensation of adipic acid and diethylenetriamine, then partially crosslinked with epichlorohydrin... 

Breslow et al. (13) have prepared an insolubilized cyclodextrin resin by crosslinking with epichlorohydrin. The resin was used for the chlorination of anisole via a three-step process. The column was loaded with anisole, that is, the available cycloclextrin cavities were filled with anisole. Aqueous HOCl was passed through and the product, 99% / -chloroanisole, was eluted with tetrahydrofuran. 

The authors first mentioned investigated an anion-exchange membrane consisting of polyethylene imine crosslinked with epichlorohydrin in equilibrium with KC1 solutions. The concentration of Cl- ions and K+ ions in the membrane were determined analytically. The mobility of the Cl- ions in the membrane was determined according to the principle of the moving boundary. Thus in a membrane strip a sharp boundary is formed between the OH- and Cl- ions. This boundary will move under the influence of an electric field. This may be made visible with the aid of an indicator. The speed of the boundary is determined by the slowest ion, by consequence the Cl- ion in this instance. 

Crosslinked resins of polyethylene imine structure have been prepared by various methods, including the reactions of polyethylene imine with epichlorohydrine 14), with allyl chloride 15), with ethylene dibromide, 6) or dichloride 17), and with toluene diisocyanate l8>. 

The water-absorption rate of the polymers can be increased by use of capillary action. It is reported that fibrous carboxymethyl celluloses, which were crosslinked with epichlorohydrin and had the carboxymethylation degree of 0.2-0.4, had high water-absorption rate of 20-40 ml/ g-polymer/min. 

Hydantoin epoxy resins having glycidyl groups in the 1- and 3-positions and one or two alkyl groups in the 5-position were prepared by the Bucherer reaction, followed by treatment with epichlorohydrin. These resins were crosslinked with hexahydrophthalic anhydride to examine the effect of alkyl substituents on the glass transition temperatures of the cured systems. 

Borax has frequently been used in conjunction with such reagents as (3-chloro-2-hydroxypropyl)trimethylammonium salts,1853 epichlorohydrin or formaldehyde,1401185318541855 melamine-formaldehyde resins,1856 (carboxymethyl) starch, oxidized (carboxymethyl)starch, (carboxymethyl)starch-acrylamide copolymer,1857 and oxidized starch.1858 Boric acid was also used jointly with formaldehyde,1859 and starch dialdehyde has been crosslinked with boric acid.526... 

Acylated starch can be copolymerized to yield materials for films, lacquers, and fibers.2111 Starch acetate copolymerized with epichlorohydrin was extruded to give cold-water swelling products with a high degree of friability.2112 Epichlorohydrin-crosslinked starch has been acylated with 2,3-di-O-benzoyl-L-threaric anhydride.2113 The reaction proceeded either in /V,/V-dimethy 11 ormam ide or in toluene, and the non-crosslinked product has also been reported.2114... 

Aminated starches have been further converted. For example, dimethyl-aminoethyl starch could be converted into glycosides by alcoholysis,2442 phosphorylated with sodium dihydrogenphosphate, and oxidized with hydrogen peroxide to carboxyl derivatives.520 Additional information on this subject can be found in Section VII. 2-Hydroxypropyltrimethylammonium chloride starch has been crosslinked with epichlorohydrin.2443 In contrast to animation, which requires basic solutions, phosphorylation occurs at pH 6.2444... 

The treatment of (cyanoethyl)starch with hydroxylamine2478 and its salts gave a cationic amidoxime which was used as a paper strengthener,2479 and it was also useful in the removal of heavy metal cations from wine.2480 An amidoxime was also prepared from epichlorohydrin-crosslinked (cyanoethyl)starch.2481 There are reports on cationic graft polymers, and these are detailed separately in Section XVI, together with other graft polymers. 

Reaction of starch dialdehyde with urea gave a condensation product.442,2633 Carboxyamides,2624 including acrylamide,524,585 were also allowed to react with starch dialdehyde. Condensation can occur between starch dialdehyde and macromolecules containing amido groups, for instance, epichlorohydrin-crosslinked polyamide resin,598 ammonia-diethylamine-epichlorohydrin copolymer,588 dicyanamide-formaldehyde resins,565,566 quaternary alkylam-monium compounds,596,610,611 amino acids,2634,2635 protein,626,2636-2639 and aminoalkylated starch.2515 The reactions are favored by low pH. The guanidino moieties of proteins entered the condensation the most readily. 

Poly(amino acids)2892 and polypeptides2893 can also be grafted onto starch. Starch was first alkylated in the presence of lithium naphthalene, and then the alkoxy derivatives were reacted with /V-carboxy anhydrides. Poly(amide amines) were produced by reacting amines with dioic acids on starch and then crosslinking with epichlorohydrin or 1,2-dichloroethane 2894 Grafting of starch with a synthetic polymer chain, for instance, polystyryl carboxylate anions prepared by an anionic polymerization, can be carried out on a blend of starch and cellulose functionalized by sulfonation, mesylation, or tosylation. In this manner, cellulose-starch graft copolymers were prepared.2895... 

Silica can be coated with polyethylene imine. The strongly adsorbed imine can then be permanently attached through crosslinking with an appropriate leagent, such as epichlorohydrine. PEI-silica has found many applications, especially as an anion exchanger for proteins and peptides. 

Biologically active agents can be covalently linked to a pol5maer. The polymer is biodegradable, such as is poly(hydroxymethylethylene hydrox miethylacetal) (81). The polymer can be crosslinked with epibromohydrin or epichlorohydrin to form a gel. Other suitable polymers are listed in Table 8.13. 

Sreedhar, B., Chattopadhyay, D.K., Karunakar, M.S.H., and Sastry, A.R.K. 2006. Thermal and surface characterization of plasticized starch polyvinyl alcohol blends crosslinked with epichlorohydrin. J. Appl. Polym. Sci. 101 25-34. 

A recent patent describes the use of poly(diallylamine)-epichlorohydrin, which is a cationic resin, for crosslinking of nonionic or anionic polymers. This cationic resin has been successfully used to crosslink anionic polymers of cellulose and guar, xanthan gum, and partially hydrolyzed polyacrylamides The nonionic polymers which can be crosslinked with this cationic resin include polyacrylamide,... 

Dextran mixed with PVP and poly(vinyl acetate) was crosslinked with epichlorohydrin to fonn beads containing herbicides. Controlled release of herbicnles. Rehab et at., 1991... 

Figure 3.9 Scanning electron micrograph of surface morphology of hydrogels prepared with pachyman (A), CMP (B) and HMP (C) crosslinked with epichlorohydrin (A and C reproduced with permission from [77] and B reproduced with permission from [213]).

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