Solvent ingress

Otero and co-workers208,212 have visually observed nuclei of oxidized polymer in thin polypyrrole films on electrodes. They attribute these to sites of counter-ion and solvent ingress. A nucleation model based on the growth of ionically conductive zones provides good agreement with experimental chronoamperometric responses. 

If the penetrant enters the glassy matrix faster than the polymer can adapt itself by volume relaxation, the solvent front advances linearly with time. This behaviour is called case-II diffusion or relaxation-controlled diffusion. It is a special case of anomalous diffusion, where the mean square particle displacement is proportional to t. It commonly applies to polymers in the glassy state [Wei2]. Here the system 1,4-dioxane/PVC is an example (Fig. 10.1.8(b)). Due to the softening of the material behind the diffusion front, the polymer relaxation in the already swollen matrix is fast enough to adapt to a new situation created by further solvent uptake. Therefore, solvent ingress as well as swelling behind the diffusion front is Fickian. 

The rubbery-solvent interface S moves due to the swelling of the polymer due to solvent ingress and by subsequent chain disentanglement. This was expressed as... 

As with moisture absorption, solvent ingress will occur through diffusion processes which are driven by thermodynamic considerations. Thus in agreement with Flory-Rehner considerations, the degree of swelling will be a function of the Flory interaction parameter and the crosslink density [29]. For this discussion, the most important consideration is the relative polarity... 

Mass change plotted against charge for a cycle in monomer-free electrolyte provides information about mobile species during oxidation and reduction. Information about rate of solvent ingress/ egress in the film can be obtained. Details on this and other applications of the EQCM can be found at www.gamry.com. 

The techniques developed for biomedical applications to study the liquid state have also been used in materials science. Such applications include the study of solvents ingressed into polymers, liquids absorbed onto porous media, and polymerization reactions [51], all of which can be studied as a function of space and time. 

The quality of various products is frequently determined by transport phenomena. In many polymeric products, resistance to solvent ingress (solvent resistance) is one of the most important properties. In some other products, such as, for example, in gloves or packaging materials, polymeric material should prevent solvent migration from one side to the other side of a barrier. In still other products, such as membranes, steady and fast flow of solvent throngh a membrane is a virtue. 

ABALYN. Hetbyl esters of abietic acid. A non-solvent ingr ient in nitrocellnlose lacquerB. Boiling range, 350 370°. Ktssh point (open), 100°, [Pg.246]

Ut or Vol Used Dec. V. Purity Ut or Vol. Active Ingred. Solvent ID Vol. Solv. Used Concentration... 

Chem. Descrip. N,N-Dimethyl caprylamide ramide Uses Mutual solvent for polar and nonpolar ingreds. in cosmetics, cleaners, corrosion inhibitor polar solvent for nat. and n. resins arid elastomers modifier for polymer coati ... 

Uses Mfg. of benzoquanamine intermediate for mbber chemicals solvent for nitrile rubter, specialty lacquers, resins and polymers, anhydrous metallic salts cosmetics ingred. 

Uses Prod, of chlorodifluoromethane (a refrigerant and propellant), fluorocarbon plastics extraction solvent for pharmaceuticals, nat. oils solvent for perfume analytical chemistry intermediate in prep, of dyes, drugs, pesticides fumigant insecticides ingred. in drugs and cosmetics preservative, solvent, flavor in pharmaceuticals in food-pkg. adhesives adjuvant for PC food-pkg. resins Features Sweet pleasant flavor... 

Uses Prod, of polyurethane and unsat. polyester resins, triethylene glycol, morpholine, paints textile softener, lubricant solvent for nitrocellulose, dyes, oils, printing inks extraction solvent dehydration of natural gas, plasticizers, surfactants humectant for tobacco, casein, and syn. sponge cork compositions bookbinding adhesives dyeing assistant cosmetics antifreeze ingred. PU chain extender processing aid ac-... 

Uses Flavors medicine organic synthesis solvent for paints cosmetics ingred. 

Uses Solvent and raw material for prod, of cellulose acetate, acetophenone, diethyl benzene, anthraquinones chem. intermediate in mfg. of styrene, other plastics, syn. rubber, styrene latexes minor component of gasoline and aviation fuels reagent cosmetics ingred. 

Uses Solvent for nitrocellulose, resins, lacquers, baking finishes, waxes, oils in fragrances cosmetics ingred. 

Uses Solvent for coatings, nilrocellulose, and other lacquers cosmetics ingred. 

Uses Crude oil demulsifier ingred. defoamer emulsifier for oils, solvents, waxes, pesticides emulsifier, protective colloid in emulsion polymerization spermicides surfactant for dishwashing detergents, cosmetics surfactant, wetting agent, dispersant for household/industrial cleaners textile scouring agent solubilizer emulsifier in mfg. of food-con-tact articles... 

Uses Disinfectant solvent for wire enamels pharmaceuticals insecticides fungicides herbicides plasticizers mbber chemicals paints additives to lubricants and gasoline mfg. of polyphenylene oxide wetting agents dyestuff synthetic resin comonomer for alkali-resist, phenolic resins froth flotation agent engine cleaner ingred. 

Uses Solubilizer solvent for many org. and inorg. compds., plastic films dye solvent, dye assistant for textiles mfg. of methylamine denaturing alcohol In organic synthesis drug intermediate in mfg. of ampicillin, cephaclor, etc. solder flux ingred. plasticizer in leather, cloth films, coatings stabilizer humectant in paper accelerator buffer in lacquers, explosives, cosmetics prep, of hypnotics photochemicals biocides cryoscopy vehicle in pharmaceuticals antidote... 

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