Resins polyvinyl alcohol

We subject envelope and stamp adhesives to stringent safety requirements. Since we re likely to swallow traces of the stuff, we have to regulate it as a food. Gum arable from the acacia tree, dextrin from corn starch, and the water soluble resin polyvinyl alcohol are the adhesives we use most often. We also... 

Urethane Resins, Polyolefin Fibers, Polyvinil Acetate Resins, Polyvinyl Alcohol Resins,Polyester Fibers... 

A weak cation-exchange resin is obtained by reaction of glyoxylic acid and a cross-linked polyvinyl alcohol. The polyvinyl alcohol is cross-linked with glutaraldehyde in the presence of hydrochloric acid. The cation-exchange resin has an exchange capacity of 3 meq/g or greater and a swelling volume of 10 ml/g or smaller (37-38). 

The packed columns of Shodex Asahipak GF/GS HQ series are made of an especially modified polyvinyl alcohol based resin (Table 6.11, page 202). 

The heat exchanger fins from aluminum or its alloy are coated with aqueous solution containing a water-soluble cellulose resin or polyvinyl alcohol and a surfactant to form a hydrophilic film. Phosphoric acid ester was used as anionic surfactant (0.05-4.5%) in aqueous solution to form a hydrophilic film showing contact angle with water of 5-32° [288]. 

A number of photopolymer printing plates are already known. Their basic structures are to combine one of the general purpose resins such as cellulose (1), polyamide (2J, polyester, poly urethane (3j, polyvinyl alcohol (4), synthetic rubber (5) and the like with photopolymerizing vinyl monomer, photopolymerization initiator and so on. Any one of the plates of such structures can be used as a press plate, but they can not be used as an original plate for duplicate plate owing to their insufficient hardness, toughness and the similar negative properties. 

Vinyl chloride polymers and copolymers are often referred to as vinyl resins. PVC is the most important member of the vinyl resin family, which includes polyvinyl acetate (PVAC), polyvinyl alcohol (PVA), polyvinylidene chloride (PVdC) and polyvinyl acetal. Almost always the term PVC includes polymers of VCM as well as copolymers that are mostly VCM. 

Uses Manufacture of polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride-acetate resins used particularly in latex paint paper coatings adhesives textile finishing safety glass interlayers. 

Materials that have been used in pyrotechnic mixtures include nitrocellulose, polyvinyl alcohol, stearic acid, hexamethylenetetra mine, kerosene, epoxy resins, and unsaturated polyester resins such as Laminae. The properties of most of these fuels can be... 

Beckman et al. (3) prepared an oil drilling surfactant composition consisting of a resin blend of two 98% hydrolyzed polyvinyl alcohols where the viscosity of one of the resin components was at least 50% greater than the other. 

Elvanol. DuPont Co trademark for polyvinyl alcohol, PVA, white to creamy-white, odorless, synthetic resin, sol in water. Used as an adhesive and binder (Ref 1) and desensitizing LA by coating it. (See Ref 2, p A558-R)... 

Polyvinyl alcohol content - 16tol9wt% calcd on a dry basis using a turbidimetric procedure consisting of sample aliquot addn to a series of std w-acet solns (differing in the proportions of w to acet) until a clear soln is formed (not turbid) indicating the appropriate wt % of the dry resin... 

Vacuum-Bag Molding. After hand lay-up, the assembly is covered with an air-tight film, typically polyvinyl alcohol, occasionally nylon or other material. Then a vacuum is pulled on the underside of the film, to let atmospheric pressure squeeze out air and excess resin. Use of a hand-held paddle may help. The assembly is allowed to stand until cured. Products are void-free, and quality is better than simple hand lay-up. 

Polymeric carbohydrates of an undetermined degree of polymerization have also been used to modify synthetic adhesive resins. In particular, cellulosic papermill sludges have been used to modify PF and UF resins (127). A carbohydrate polymer was reported to be an excellent extender and modifier for polyvinyl alcohol adhesives (128). 

It should also be mentioned that stearic acid or graphite is some times added in small amounts as an additive to smoke compositions. These materials serve as a lubricant, which really helps reduce sensitivities (especially to friction and impact) of smoke mixes. As for pyrotechnic binders in smokes, vinyl alcohol acetate resin (VAAR) has been used in the past. The most commonly used binder system now in smokes is polyvinyl alcohol (PVA), and it is applied wet. 

A direct relation between the polymer foams density (respectively, the expansion ratio) and the oligomer content in it has been established [114], Addition of water soluble polymers (polyvinyl alcohol, carboxymethyl cellulose, etc.) led to a reduction in resin consumption without deteriorating the quality of the solid foam obtained. Polymer foams of density 5-7 kg m3 were produced when the oligomer consumption was not more than 15-20% with respect to the solution volume. 

The chemicals used for coating and laminating are polymeric materials, either naturally occurring or produced synthetically. These include natural and synthetic rubbers, polyvinyl chloride, polyvinyl alcohol, acrylic, phenohc resins, polyurethanes, silicones, fluorochemicals, epoxy resins and polyesters." Coating formulations typically include auxiliaries such as plasticizers, adhesion promoters, viscosity regulators, pigments, fillers, flame retardants, catalysts and the like. ... 

BURCO FINISH 55 is used primarily in finishing baths for fabric stiffening. It is a very efficient and economical hand builder. It tends to produce a stiff, full leathery hand as opposed to the thin, crisp hand produced by polyvinyl alcohol and starch derivatives. Being nonionic in nature, it is highly compatible with a wide variety of resins, softeners, catalysts and other finishing bath components. 

PERMAFRESH MEL resin reacts with starches and synthetic polymers such as polyvinyl alcohol and acrylates. Alone, PERMAFRESH MEL resin provides a firm hand on polyester and nylon fabrics and reacts with cellulosic fabrics to provide shrinkage control. PERMAFRESH MEL resin also aids in obtaining and maintaining satisfactory results when used with water and/or oil repellent products. 

SEQUAPEL ND provides excellent spray ratings--even when applied with high levels of handbuilders such as polyvinyl acetate, polyvinyl alcohols, or starch ether. SEQUAPEL ND can also be used with thermosetting resins. 

The use of imprinted polymer ion separation and photometric detection has been demonstrated for Pb [19] and for U02 [35]. In the case of Pb ", the imprinted Pb " resin described above was packed into columns and used to remove Pb " from tap and seawater at a variety of pH values [8], The extraction efficiency of the imprinted resin was compared to the efficiency of an imidodiacetate resin (Chelex-100), a thiol-functionalised resin (Duolite G-73) and a high-capacity polyacrylic acid/polyvinyl alcohol resin (a proprietary NASA resin). The imprinted polymer s extraction efficiency was equal or better than the other resins and the effluents from the imprinted polymer resin were shown to be virtually free of contamination by other metal ions (Fig. 19.13). The purity of the effluent allowed the determination of Pb using a very non-specific colorimetric reagent, dithizone. The method is suitable for automation as an FIA technique. 

Recently [43] Gao et al. applied a zeolite-fiOlled polyvinyl alcohol (PVA) membrane in esterification and acetalization reactions. Zeolites NaA, KA and CaA as well as NaX were loaded into PVA up to 27 wt% and the composites tested in selective water removal during reaction. A pervaporation cell with a membrane area of 22.9 cm was coimected to a collection system kept at a vacuum of 0.1 mm Hg. A sulfonated resin was used as Bronsted acid catalyst in the esterification mixture (120 ml). Figure 28 shows the progress of the esterification of salicylic acid and methanol at 60°C. The reaction is accelerated considerably as a result of the water removal. 

The materials employed for making hollow microspheres include inorganic materials such as glass and silica, and polymeric materials such as epoxy resin, unsaturated polyester resin, silicone resin, phenolics, polyvinyl alcohol, polyvinyl chloride, polyjM-opylene and polystyrene, among others, commercial jx oducts available are glass, silica, phenolics, epoxy resin, silicones, etc. Table 36 shows low-density hollow spheres. Table 37 shows physical properties of glass microspheres, and Table 38 shows comparison of some fillers on the physical properties of resulting foams (10). 

The raw materials for making hollow microspheres include glass, phenolic resin, epoxy resin, polystyrene, silicone rubber, polyvinyl chloride, polyvinyl alcohol. SOHIO Chemical Co. developed two methods, as shown below. 

Madders. Phenolic polymers are known to have high rigidity, and this property extends to phenolic foams, which are highly friable. In order to reduce friabUity and permit some flexibUity and toughness, various kinds of modifiers are sometimes used. Reactive modifiers are used in the course of resol-resin preparation, and they become integral parts of the polymer structure. Examples include PVA (polyvinyl alcohol), PVA-PVC (polyvinyl alcohol-polyvinyl chloride-copolymer), resorcinol, o-cresol, furfuryl alcohol, and other various types of polyols. 

Properties Somewhat viscous liquid. Bp 143C (2.5 mm Hg), fp approximately -72C, d 1.170 (25/4C), flash p 347F (175C). Miscible with water, alcohol, and glycerol. Compatible with polyvinyl alcohol, many cellulosic and natural resins. Combustible. 

Properties Liquid. Solidification point 71-74C. Formaldehyde condensation products are permanently thermoplastic and water soluble. As increasing amounts of simple urea are mixed with ethanolurea, the condensation products gradually change from pliable film-forming resins into the brittle types. Thus, almost any degree of water solubility and flexibility may be obtained in the final resin. The modified resins formed with ethanolurea are compatible with polyvinyl alcohol, methyl cellulose, cooked starch, and other water-dispersible materials. 

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