Nonionic cellulosics

Properties. Hydroxypropylcellulose [9004-64-2] (HPC) is a thermoplastic, nonionic cellulose ether that is soluble in water and in many organic solvents. HPC combines organic solvent solubiUty, thermoplasticity, and surface activity with the aqueous thickening and stabilising properties characteristic of other water-soluble ceUulosic polymers described herein. Like the methylceUuloses, HPC exhibits a low critical solution temperature in water. 

Nonionic cellulose ethers, hydroxyethyl(HE) and hydroxypropy1 (HP) cellulose, of variable molar substitution (M.S.) levels, were adsorbed on peptized sodium montmorillonite surfaces from fresh and saline (NaCl) aqueous solutions. The amounts adsorbed for 2 M.S. HEC and HPC and 4 M.S. HEC were insensitive to electrolyte concentration the 4 M.S. 

With increasing electrolyte (sodium chloride) concentration there appears to be a slight increase (within experimental error) in adsorption among the lower M.S. nonionic cellulose... 

Figure 4 Adsorption (g/g) dependence of nonionic cellulose ethers (2500 ppm) on salinity (N, NaCl) of aqueous solution.

Figure 9 Adsorption (rag/g) dependence of nonionic cellulose ethers (2500 ppm) on salinity (N, NaCl) of aqueous solution. Substrate Berea sand (85 wt.%) blended with montraorillonite (15 wt.%). W-SP symbols ...

Hydroxypropylcellulose (HPC) is a thermoplastic nonionic cellulose ester that is soluble in both water and a number of organic liquids. It is synthesized through reaction of the basic cellulose slurried with propylene oxide. 

The nonionic cellulose ethers have been found suitable for use with synthetic fibers [3, 4]. 

Hydroxyethyl cellulose (O Fig. 24) is a nonflocculating, nonionic cellulose ether that has side chain extensions expressed in MS/DS-ratios of about 1.5 to 3.5. HECs are used in latex paints owing to their excellent interaction ability with solids. 

If nondeionized water is used, product viscosity remains low and a thickener must be incorporated. Excellent thickening effects have been obtained with nonionic cellulose derivatives, cationic guar gum, or crosslinked cationic polyacrylates. 

The adsorption of nonionic cellulose derivatives (HPMC 2910, HEC, and HPC) and their stabilizing effect on suspensions of polystyrene latices and of the antirheumatismal ibuprofen have been examined by Law and Kayes [117, 118]. Adsorption isotherms (see Fig. 20 for HPMC and ibuprofen) are of a sigmoidal type rapid initial adsorption, then a plateau corresponding to monolayer adsorption and finally a further increase in adsorption. At the same time, a gradual reduction in the sedimentation volume (decreased flocculation) is observable, while the redispersibility tends to be optimum (minimum number of revolutions necessary) at values of HPMC corresponding to a monolayer surface coverage. 

Hydrophobically modified nonionic cellulose ethers or poly(ethylene oxide) (HMPEO) act as unique stabilizers in suspension polymerization of vinyl and acrylic monomers (IS). The use of HMHEC as a stabilizer in emulsion polymerization of vinyl and allylic monomers has also recently been reported (16). 

Momcilovic et al. were able to significantly enhance sensitivity by labeling partially depolymerized nonionic cellulose ethers with dimethylamine. It is also possible to introduce a permanent charge directly, as reported for oligosaccharides, for... 

C. Alvarez-Lorenzo, R. A. Lorenzo-Ferreira, J. L. Gomez-Amoza, R. Martinez-Pacheco, C. Souto, and A. Concheiro, A comparison of gas-liquid chromatography, NMR spectroscopy and Raman spectroscopy for determination of the substituent content of general nonionic cellulose ethers, J. Pharmaceut. Biomed. Anal, 20 (1999) 373-383. 

Although the membrane used for reverse osmosis may be ionic and ion-exchange can occur, there is, however, no overall transmission of salt because of Dorman exclusion (and unlike electrodialysis no electric current is applied). Thus, while an essential requirement of a membrane for reverse osmosis is hydrophilicity, it need not be ionic. In fact, the most successfiil reverse osmosis membranes developed are made of nonionic cellulose acetate. Certain ionic polymers, such as the sufonated polyaromatics, has been used because of their greater chemical stability and resistance to biological degradation. 

This nonionic cellulose ether is soluble in cold water, ethanol, and mixtures of ethanol and water. 

The flocculant based on cellulose can be generally classified into four major groups [i] cationic cellulose-based-flocculant, (ii) anionic cellulose-based flocculant [41], (Hi) amphoteric cellulose-based flocculant, (iv) nonionic cellulose-based flocculant [42] as follows ... 

Carlsson, A., Karlstrom, G. and Lindman, B., Thermal gelation of nonionic cellulose ethers and ionic surfactants in water. Colloids Surf., 47, 147-165 (1990). 

Scherlund, M., Malmsten, M. and Brodin, A., Nonionic cellulose ethers as potential drug delivery systems for periodontal anaesthesia, J. Colloid Interface Sci., 229, 365-374 (2000). 

Figure 20.33. The extension of an adsorbed polymer layer can be strongly modified on the association of an ionic surfactant due to electrostatic interactions. On addition of an ionic surfactant (sodium dodecyl sulfate) (SDS) to an adsorbed layer of a nonionic cellulose ether (ethylhydroxyethyl cellulose) (EHEC) there is a dramatic increase in the thickness of the adsorbed layer (filled circles) while there is little change in the total adsorbed amount (open circles). (By courtesy of Fredrik Joabsson)...

The raw materials are cotton linters, soft wood pulp or dissolving pulp. They must be high in alpha - cellulose content, free of metals and uniformly absorb water and the NaOH solution. The other starting materials include alkylene oxides and alkyl chlorides for the preparation of nonionic cellulose ethers and sodium monochloroacetate for anionic types such as sodium carboxymethyl cellulose. 

Hutter JM, Clarke MT, Just EK, Lichtin JL, Sakr A. The influence of nonionic cellulosic polymers on uptake of polyquaternium-10 by bleached hair. J Soc Cosmet Chem 1992 43 229-235. 

Thuresson K, Nilsson S, Lindman B. Influence of cosolutes on phase behavior and viscosity of a nonionic cellulose ether. The effect of hydrophobic modification. Langmuir 1996 12 2412-2417. 

In a second publication Hutter et al. (70) examined the individual effects of adding various nonionic cellulosic polymers on the uptake of Polymer JR 400 by bleached hair. The effects observed were generally not major. Competitive effects may well have been stronger on virgin hair, which is more hydrophobic, and where hydrophobic effects with... 

SA1 Samii, A. A., Karlstidm, G., and Lindman, B., Phase behavior of a nonionic cellulose ether in nonaqueous solution, Langmuir, 1,653, 1991. 

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