Resin matrices alkali

When the macroporous resin column was used with the same acidic eluent in 100 % methanol, the chromatographic separation was improved considerably. Now the alkali-metal ions are solvated with methanol and the resin matrix is probably coated with a thin layer of methanol, which makes the ions and the resin surface more compatible with one another. 

Ray D, Sarkar BK, Das S, Rana AK (2002) Dynamic mechanical and thermal analysis of vinylester resin matrix composites reinforced with untreated and alkali-treated jute fibers. Compos Sci Technol 62 911-917... 

Ray, D., Sarkar, B.K., Rana, A.K., and Bose, N.R. (2001) The mechanical properties of vinylester resin matrix composites reinforced with alkali-treated jute fibers. Composites Part A, 32, 119-127. 

Starting from the corresponding hydroxymethyl-benzocrown, it has been possible to generate the immobilized system (186) by reacting the above precursor with chloromethylated polystyrene (which is available commercially as Merrifield s resin). Typically, systems of this type contain a polystyrene matrix which has been cross-linked with approximately 1-4% p-divinylbenzene. In one study involving (186), a clean resolution of the alkali metal halides was achieved by HPLC using (186) as the solid phase and methanol as eluent (Blasius etal., 1980). In other studies, the divalent alkaline earths were also separated. 

The most widely used positive resists are those that operate on the basis of a dissolution inhibition mechanism. Such resists are generally two-component materials consisting of an alkali soluble matrix resin that is rendered insoluble in aqueous alkaline solutions through addition of a hydrophobic, radiation-sensitive material. Upon irradiation, the hydrophobic moiety may be either removed or converted to an alkali soluble species, allowing selective removal of the irradiated portions of the resist by an alkaline developer. 

The chelating ion-exchange resins Chelex-100 and Permutit S 1005 completely retain vanadium [Sc, Ni, Cu, Zn, Y, Mo, Ag, Cd, In, rare earths, W, Re (90%), Pb, Bi, and Th] from sea water. Manganese is retained quantitatively only by the Chelex resin. Vanadium (Mo, W, Re) is removed from the resins with 4N ammonia, the other metals with 2 N mineral acids 56). Both resins consist of a cross-linked polystyrene matrix with iminodiacetic acid [—CH2—N(CH2COOH)2] functional groups. Alkali and alkaline earth metals do not form chelates with iminodiacetic acid except at very high pH, whereas many transition metal ions form 1 1 complexes. 

Effect of fiber treatments Alkali treatment on OPFs significantly improved its interfacial shear strength in polyester matrix [14]. Alkali treatment washed out the outer skin, better exposing fiber to the polyester matrix, leading to proper interaction between their surfaces. In addition, the fine holes created on alkali treatment allowed the polyester to penetrate into the fiber bundles in a better way. Acetylation treatment to the fibers improved impact strength of OPF-polyester composites due to improved fiber wettability and resulting fewer void spaces [71]. The tensile stress of OPF-polyester composites increased slightly upon both acetylation and silane treatments on fibers and decreased upon titanate treatment [14]. The flexural modulus of OPF-PP composites also increased considerably upon acetylation treatment on fibers. Similarly the abrasion resistance of OPF-polyester composites was enhanced upon alkali treatment to fibers [13]. Treated fibers enhanced the adhesion resistance of polyester resin by 75-85%, while untreated fibers enhanced the abrasion resistance only by 50-60%. 

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