Crosslinked cellulose

The advanced applications for nitrocellulose plastisol propellants require that they be integrally bonded to the motor case. Successful case bonding for the multiyear storage life of a rocket calls for special adhesives and liners which are completely compatible with these highly plasticized propellants. Best results have been obtained with a combination of an impervious rubber liner and a crosslinked adhesive system with a limited affinity for the plasticizers used in the propellants. Examples of effective liners are silica-filled butyl rubber and chlorinated synthetic rubber. Epoxy polyamides, isocyanate-crosslinked cellulose esters, and combinations of crosslinked phenol-formaldehyde and polyvinyl formal varnishes have proved to be effective adhesives between propellant and impervious liners. Pressure curing of the propellants helps... 

Picard, et al, Fabric Reinforced Crosslinked Cellulose Nitrate Propellants for Recoilless Weapons , PATM 2057 (1973)... 

The preparation of cellulose copolymers with vinyl monomers, which have functional groups that are hydrophilic in nature, has given textile products with improved soil release properties. For example, as shown in Figure 5, crosslinked cellulose-poly (methacrylic acid) copolymer fabrics exhibited both increased oily and aqueous soil release during washing compared with the crosslinked control fabrics. However, for oily soil, when softeners were added to the wash water, this improvement in soil release decreased. Crosslinked cellulose-poly (hydroxyethyl methacrylate) copolymer fabrics exhibited no improvement in oily soil release and only slight improvement in aqueous soil release compared... 

Preparation of Cellulose-Polystyrene Graft Copolymers. The polystyr-yl mono- and di-carbanions were prepared in THF at -78 °C by using n-butyl lithium and sodium naphthalene as the initiators, respectively. The carban-ions were reacted with dry carbon dioxide. The products were precipitated in methanol, filtered, washed with water and methanol, and dried. Size exclusion chromatography (SEC) established that the molecular weight of the polystyryl monocarboxylate was 6,200 and that of the polystyryl di-carboxylate 10,2000. The mono- and di-carboxylates were reacted with mesylated cellulose acetate in dimethylformamide at 75 °C for 20 h to give the cellulose-polystyrene graft copolymer (GP 1) and crosslinked cellulose-polystyrene graft copolymer (GP 2), respectively. 

Metal chelating amino acid derivatives of cellulose were recently obtained via modification of cellulose with 2,4-toluenediisocyanate, followed by treatment with amino acid ester derivatives [58,59]. Diisocyanates are able to crosslink cellulose chains and/or to yield reactive cellulose isocyanate, depending on the reaction conditions. Sato and his coworkers [60] examined the optimum conditions for the reaction between cellulose and 2,4-toluenediisocyanate and succeeded in introducing 0.30 mol of free isocyanate group per glucose unit. Cellulose isocyanate was further converted into isothiocyanate [61]. This derivative has also been synthesized by condensation of cellulose with 2,4-diisocyanototoluene, followed by hydrolysis and thiophosgene treatment [61]. 

Duval [2] prepared three-dimensional chromatographic polysaccharide supports for use in asymmetric synthesis by crosslinking cellulose-g-(4-alloxy-phenyl-carbamate), (II), with mercaptopropyl silica, (III). 

Fixation of dyestuffs and pigments by incorporation in the crosslinked cellulose and in the finish network, also providing better wet fastness for conventional dyeings and printings Cellulosics mainly with direct and acid dyes, cotton/polyester blends with reactive dyes, preparation for dry heat transfer printing of cellulosics ... 

As far as biopolymers other than plain cellulose are concerned, grafting has been reported for crosslinked cellulose, oxidized cellulose, carboxymethylated cellulose, cellulose acetate and even for crosslinked derivatives. The grafted material content is usually given as the ratio of the increase in weight to the initial cellulose weight. 

Conventionally produced cellulose powders (microcrystalline cellulose) consist of irregularly shaped fibrous particles of limited use for column chromatography. Beaded cellulose is prepared by dissolution of cellulose powder in a suitable solvent, followed by droplet formation in a suspension medium, and subsequent solvent extraction or crosslinking. Cellulose triacetate and tricarbamate derivatives are useful as low-cost sorbents for the process-scale separation of enantiomers (section 10.4.2). 

Wang, C. Chen, C. Physical properties of the crosslinked cellulose catalyzed with nanotitanium dioxide under UV irradiation and electronic Held. Appl. Catal. A 2005, 293 (2B), 171-179. 

Castro, C., Vesterinen, A., Zuluaga, R., Caro, G., Filpponen, 1., Rojas, 0. J., Kortaberria, G., and Ganan, P. (2014). In situ production of nanocomposites of poly(vinyl alcohol) and cellulose nanofibrils from Gluconacetobacter bacteria Effect of chemical crosslinking. Cellulose, in Press. 

Synonyms Croscarmellose (INCI) Crosslinked carboxymethyl cellulose Crosslinked cellulose gum Crosslinked CMC Crosslinked NaCMC Crosslinked sodium carboxymethylcellulose Crosslinked sodium CMC Sodium salt of crosslinked carboxymethyl ether cellulose Definition Sodium salt of thermally crosslinked carboxymethylated cellulose Properties Wh. to off-wh. free-flowing powd. odorless partly sol. in water insol. in ether, alcohol, org. soivs. pH 5-7 (1% disp.)... 

Crossential SA-14. See Vipers bugloss (Echium plantagineum) oil Crosslink PS 505. See Polyethylene Crosslink WA 405. See Dodecylbenzenesulfonic acid Crosslinked carboxymethyl cellulose Crosslinked cellulose gum Crosslinked CMC Crosslinked NaCMC. See Croscarmellose sodium... 

Reactions of cellulose with diisocyanates have been used to crosslink cellulose. 

Cotton and other cellulosic fabrics, and blends, usually require reactive cross-linking finishes to provide improved bending properties (i.e., crease behavior) and shrinkage. The products of choice for crosslinking cellulose are N-methylol compounds, which are made by reacting urea with formaldehyde and other additives. In application, storage, and use, these reactive A-methylol crosslinkers release formaldehyde to the air. 

Pierre-Antoine F, Francois B, Rachida Z. Crosslinked cellulose developed by CuAAC, a route to new materials. Carbohydr Res. 2012 356 247-51. 

Poly(iV-vinyl pyrrolidone-co-2-hydroxyethyl methacrylate-co-itaconic acid)-Grafted on Trisodium Citrate Crosslinked Cellulose Acetate-coated chitosan [p-g-CT-NagCit-CAc],... 

Step 1. Synthesis of Trisodium Citrate-Crosslinked Cellulose Acetate-coated chitosan (CT-Na Cit-CAc) Heavy and tight liquid paraflms (1 1 ratio) with 0.4 ml Tween 80 were added to 500ml beaker at ambient temperature with continuous stirring. CT (2%, w/v) dissolved in acetic acid solution was added in drops to the above solution... 

Figure 8 A polysaccharide based nanofoam, based on a crosslinked cellulose ester made controlled SC-CO2 drying of the gel in acetone. A field-emission-gun-SEMphotograph shows the nanoporous structure. The inset is a photograph of the dried product (0.5 cm large piece).

Many new materials have been developed for transporting water effectively and separately [6-9], including crosslinked cellulose called curly fibers, thermally fused PE/PP fibers, and a special nonwoven rayon cloth. These new materials absorb a liquid quickly and distribute it to the superabsorbent polymer. In addition, these new materials show good integrity to moisture. In particular, there is no corruption of the structure even after wetting, allowing the maintenance of chaimels through which the liquid ean be transferred. 

Finally, with regard to revolutionary design, many systems adopt an acquisition layer or a combination of an acquisition layer and transport layers between the absorption core (Fig. 2) and the top sheet [9]. For the acquisition layer or the transport layer, either a crosslinked cellulose with a density of 0.04-0.1 g/cm, thermally fused PE/PP fibers, or a nonwoven cloth is used. The absorption core consists of surface-crosslinked superabsorbent polymer and pulp. In general, the concentration of the superabsorbent polymer is 40 to 60 wt %, and the weight of the polymer used per diaper is approximately 10 to 12 g [9,10]. 

Zhang, W., Zhang, Y., Lu, C. et al. (2012) Aerogels from crosslinked cellulose nano/micro-fibrils and their fast shape recovery property in water. /, Mater. Chem, 22 (23), 11642-11650. 

Water swollen gels produced from several different polymers have been tested with this apparatus, including crosslinked cellulose ethers, poly(N-isopropylacrylamide), and poly(2-hydroxyethylmethacrylate). Typical plots of stress vs. are shown in... 

Cheng, J., Parl M., and Hyun, J. (2014). Thermoresponsive hybrid hydrogel of oxidized nanocellulose using a polypeptide crosslinker. Cellulose, 21,1699-1708. 

Upon crosslinking cellulose becomes essentially inert toward benzoyl chloride or phenyl isocyanate. ... 

---