Cellulose ethers polymerization

In evaluation of polymeric cationic cellulose ether derivatives to be used as ingredients for hair shampoos, developed specifically to improve performance... 

DC Harsh, SH Gehrke. Modeling swelling behavior of cellulose ether hydrogels. In M El-Nokaly, D Piatt, B Charpentier, eds. Polymeric Delivery Systems. ACS Symp Ser 520. Washington, DC American Chemical Society, 1993, pp 105-134. 

For an erosion-induced drug delivery system compactable cellulose ethers are suitable polymers [103]. Drug release, which is controlled by the erosion/dissolution of these polymeric layers, may be pH-dependent if an acid or basic polymer is used. 

A number of after-treatments with polyester copolymers carried out after sodium hydroxide processing are reported to produce a more hydrophilic polyester fabric (197). Likewise, the addition of a modified cellulose ether has improved water absorbency (198). Other treatments used on cotton and blends are also effective on 100% polyester fabrics (166—169). In this case, polymerization is used between an agent such as DMDHEU and a polyol to produce a hydrophilic network in the synthetic matrix (166—169). 

Examples of aqueous coating solutions include water-soluble low molecular weight cellulose ethers, emulsion polymerization latexes of polymethacrylates, and dispersions of water-insoluble polymers such as ethyl-cellulose in the form of pseudolatex. These solvent-free coating solutions provide a range of different coatings... 

Cellulose ethers, more particularly methyl cellulose (MQ, methylhydroxypro-pyl cellulose (MHPC) and hydroxypropyl cellulose (HPC) are used as protective colloids also called primary suspending agents in suspension polymerization for the manufacturing of S-PVC. Their role is maintaining the particle size of the resin. Hydroxyethyl cellulose (HEC) is preferred for manufacturing of vinyl acetate emulsion polymers and as a thickening agent in dispersimi paints. 

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). 

Incorporation of long-chain hydrocarbon hydrophobes into a cellulose ether backbone leads to an interesting new class of polymeric surfactants. Their enhanced solution viscosity can be explained in terms of intermolecular associations via the hydrophobe moieties. Entropic forces cause the polymer hydrophobes to cluster to minimize the disruption of water structure. The same thermodynamic principles that are used to explain the micellization of surfactants can be applied to explain the solution behavior of HMHEC. HMHECs interact with surfactants that modify their solution viscosities. The chemical nature and the concentration of the surfactant dictate its effect on HMHEC solution behavior. The unique rheological properties of HMHEC can be exploited to meet industrial demands for specific formulations and applications. 

Auxiliaries. Dispersants ensure that the individual particles in the emulsion paint do not combine to form agglomerates. Protective colloids and emulsifiers are used during emulsion polymerization to ensure that small polymer spheres are formed in the aqueous phase but do not fuse together. They influence film formation of the emulsion paint and can cause foaming. Protective colloids include polyfvinyl alcohols) and cellulose ethers. Emulsifiers include anionic and nonionic surfactants. 

Similar to all other auxiliaries, thickeners influence the water retention and open time, water resistance, washfastness, abrasion resistance, weather resistance, and gloss. The most important thickeners are methyl cellulose and hydroxyethyl cellulose. The viscosity rises with increasing polymerization of the cellulose ether. Synthetic thickeners based on poly(meth)acrylates, polyvinylpyrrolidone, and polyurethanes are also important. Inorganic thickeners include layer silicates of the montmorillonite type (e.g., aluminum silicate and magnesium silicate). They confer a better washfastness and abrasion resistance than the cellulose ethers and polyacrylates. However, they develop a lower water retention capacity (open time). 

The effect of the amount of surfactant SDS, hydrophobe hexadecane, iron oxide magnetic particles, MAA and non-ionic cellulose ether, hydroxyethylcellulose, on the magnetic latex morphology, surface quality and size distribution was studied by Forcada et al. for the encapsulation of magnetic particles by miniemulsion polymerization of St. Optimal conditions were 2-3% of SDS, 9-12% of hexadecane, 10% of iron oxide and 2% of HEC, relative to the total amount of St and iron oxide [177]. 

NFPA Health 1, Flammability 2, Reactivity 0 Uses Fragrance in cosmetics, perfumes, detergents, tech, prods. solvent for cellulose ethers and esters intennediatefor pharmaceuticals, resins, paints, etc. synthetic flavoring agent in foods and pharmaceuticals polymerization catalyst organic synthesis drug (to induce sleep) Features Sweet flavor... 

Water-soluble substituted celluloses are another class of stabilizers used in the suspension polymerization, mainly in the manufacture of PVC. These stabilizers are soluble in both the vinyl chloride and the aqueous phase [20]. Ckjnsequently, the stabilizer can also affect the stabihty of the primary particles inside the polymerizing monomer droplets and, thus, the final porosity of the PVC particles. Hydroxypropyl methylcellulose (HPMC) is a cellulose ether, produced byreacting cellulose with propylene oxide and methyl chlorine in an alkaline medium. As a result, a fraction of the hydroxyl groups (hydrophilic groups) of the cellulose... 

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