Poly -based resins

The in situ process is simpler because it requires less material handling (35) however, this process has been used only for resole resins. When phenol is used, the reaction system is initially one-phase alkylated phenols and bisphenol A present special problems. As the reaction with formaldehyde progresses at 80—100°C, the resin becomes water-insoluble and phase separation takes place. Catalysts such as hexa produce an early phase separation, whereas NaOH-based resins retain water solubiUty to a higher molecular weight. If the reaction medium contains a protective coUoid at phase separation, a resin-in-water dispersion forms. Alternatively, the protective coUoid can be added later in the reaction sequence, in which case the reaction mass may temporarily be a water-in-resin dispersion. The protective coUoid serves to assist particle formation and stabUizes the final particles against coalescence. Some examples of protective coUoids are poly(vinyl alcohol), gum arabic, and hydroxyethjlceUulose. 

Table 10. Properties of Poly(phenylene ether)-based Resins ...

Polyesters [2] find use in fibers [poly(ethylene terephthalate), poly(ethylene oxybenzoate), poly(ester ethers), poly(ester amides), etc.] [1], coatings (especially unsaturated polyesters) [4], plasticizers, adhesives, polyurethane base resins, films, etc. Cross-linked polyesters prepared from glycerol and phthalic anhydride (alkyd resins) have been reviewed [20], High-melting poly aryl esters have been investigated for high-temperature applications. 

Chemical methods used for the determination of hydroxyl groups or alcoholic constituents in polymers are based on acetylation [16-18], phthalation [18], and reaction with phenyl isocyanate [18,19] or, when two adjacent hydroxy groups are present in the polymers, by reaction with potassium periodate [9,17]. Alcoholic hydroxyl groups may be found in the following polymers (1) poly(ethylene terephthalate) (PET) [20], (2) poly(methyl acrylate), [21], (3) poly(methyl methacrylate) [21], and (4) polyhydric alcohols in hydrolysates of poly(ester) resins [22]. 

Transparent resins are used as the materials for molded products, such as automobile components, illumination equipment, and electrical components. Transparent resins, which can be applied to such applications, include poly(carbonate) (PC)-based resins and acrylic-based resins. 

However, the most important furan resins are those produced with 2-furfuryl alcohol, for example, the 2-furfuryl alcohol-formaldehyde-based resins, which are normally synthesized by a condensation reaction catalyzed by acidic sites and promoted by heat [224] or the poly(furfuryl alcohol) thermosetting resin that is usually synthesized by the cationic condensation of its monomer 2-furfuryl alcohol, which polymerizes exothermically in the presence of a catalyst such as acid and iodine in methylene chloride, producing black, amorphous, and branched and/or cross-linked structures [225],... 

F. 8. Rate of salt uptake from 0.02 N salt solution by thermally r nerable plum pudding resins containing the same De-Acidite G and Zeo-K.arb 226 plums, and 30% matrix by weight, as a function of the nature of matrix. Particle size 14-52 mesh, BSS, base resin to acid resin ratio 2 5. (1) ethyl cellulose (2) polysalt (3) crosslinked poly (vinyl alcohol) (4) normal De-Acidite G and Zeo-I b 226 mixed bed... 

The first 15-20 years of the marine uranium projects were involved with the development of hydrous titanium oxide-based sorbents. During the last 10-15 years, directions of this study have changed and the preparation mainly of poly(acrylamidoxime) resins and their modifications has been sought. 

Recently, Schuhmann et al. reported ethanol biosensors by entrapping quinohemoprotein alcohol dehydrogenase and Os-complex-modified poly(vinyl imidazole) during the electrochemically induced deposition of the poly(acrylate)-based resin [80]. The sensor exhibited its efficiency and also sufficient stability for practical applications. Author claims that the reported sensor preparation process is simple, easy to control, oxygen insensitive and can be applicable to other enzyme sensors. 

Also in 2000, attachment of the Jacobsen catalyst to polymeric supports such as poly(ethylene glycol) and different polystyrene-based resins through a glutarate spacer was described [28]. Soluble as well as insoluble polymer-bound complexes were employed as catalysts in the epoxidation of styrene, cfs-2-methylstyrene, and dihydronaphthalene with wx-CPBA/NMO. Results were similar to those achieved with the nonsupported catalyst. Catalyst recycling was shown to be possible either by filtration or by precipitation and one catalyst system could be used for three cycles without significant loss of activity and enantioselectivity. 

The water based poly(ester-imide) wire enamel from Table 3 has the same resin composition as the cresol free solvent based resin 2. It can be seen that the mechanical and thermal properties of the water based varnish are inferior to the noncresylic product. It was also found that minor amounts of drawing agent residues from copper wire manufacturing were highly detrimental to the surface quality of the enameled wires. 

There is experimental evidence to support the estimate that t/H = t/Na in this system. In the research of Travers and one of the present authors (2), a study of the complexation of divalent metal ions by poly-methacrylic acid (PMA) showed that deviation from ideality with a of the divalent ions exposed to the same potential as the H+ ion was described exactly by the deviation term deduced from the potentiometric properties of the PMA. Additional evidence for this estimate is available in the ion-exchange literature (3,4,5). At a relatively low cross-linking percentage (2 wt % divinyl benzene) j/h is about equal to t/Na> as evidenced by the ion-exchange distribution of Na+ and H+ between a polystyrene sulfonate-based resin and a simple dilute electrolyte mixture of Na+ and H+ (Na H+, X"). The selectivity coefficient measured over the complete composition range of the resin deviates very little from unity to demonstrate this as an experimental fact (KHNa = 1.02 zt 0.02... 

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