Alkaline resistant

Poor alkaline resistance (e.g. not suitable for application to concrete) ... 

Phenolic coatings Phenolic is reacted with formaldehyde under heat to form a completely insoluble material. They are usually applied in an alcohol solution by spray, dip or roller. During their curing, they release water, which must be removed. They have maximum chemical and solvent resistance but poor alkaline resistance. 

At strong alkaline conditions mono- and oligosaccharides are weak anions. So it is possible to separate them on alkaline-resistant HPLC columns. Whereas spectrophotometric monitoring is not possible, pulsed amperometric detection allows sensitive identification in the nanomolar range. 

Portland cement brick is being manufactured and used to line some pulp and paper mill vessels. These bricks are composed of Portland cement and a highly alkali resistant aggregate. The Portland cement brick presently available measures 19.37 cm (7.625 inches) by 22.86 cm (9 inches) by 6.35 cm (2.5 inches). The aggregate is specially selected for its alkaline resistance and is sized to produce a brick of optimum density. The density achieved in the currently available brick is 2.2-2.3 g/cc (138-145 Ib/ft ). The compressive strength of these brick is approximately 4,220-5,625 kg/cm (6,000-8,000 psi) with a cold water absorption of 4-6 weight percent. 

Kobayashi, K. Chiba, K. Sohn, D.-R. Kato, Y. Ishizaki, T. Simultaneous determination of omeprazole and its metabolites in plasma and urine by reversed-phase high-performance liquid chromatography with an alkaline-resistant polymer-coated C18 column, J.Chromatogr., 1992, 579, 299-305... 

Alkaline resistance An important chemical property of the phosphate layers is their ability to resist attack by hydroxide ion when exposed to alkaline electrolytes [36, 39]. Such an exposure may occur during (1) the cationic deposition of paint (by imposition of a cathodic current) (2) during subsequent alkaline degreasing operations (in particular for prephosphated steel products) and (3) under the paint layer during cathodic delamination. The destruction of the phosphate layer by the alkaline... 

Copolymers were prepared by the melt condensation method using dimethyl 2,6-naphthalate. The crystallinity and the density of annealed films decrease with increasing content of comonomer and length of alkyl side chain in the comonomer. The alkaline resistance is considerably increased by the incorporation of a comonomer having an alkyl side chain. 

PROPERTIES OF SPECIAL INTEREST Polyurea fibres have high melting points, low specific gravity, excellent dyeabiHly, and good acid and alkaline resistance. Polyurea coatings have lower solvent and better water resistance compared to polyurethanes. They have good blood compatibility. 

Features Nonsilicone exc. foam knockdown and persistence good alkaline resist. 

The following are the properties required for a geosynthetic to be used in pavement rehabilitation or new pavement asphalt works tensile strength and elongation (in both directions), bitumen retention, durability, alkaline resistance (in case a geogrid or a geocomposite is used over concrete surface) and melting point, to name a few. Property requirements and other characteristics are specified in CEN EN 15381 (2008), ASTM D 7239 (2013) or other relevant standards. 

Chitin and chitosan have high organic solvent resistance, which is advantageous for separation membranes used with organic solvents, where chemical resistance is typical. Specifically, chitin is highly acid resistant and chitosan is highly alkaline resistant. These characteristics make it possible for chitin and chitosan to be used as separation membranes for a variety of uses in response to specific requirements. 

The investigations mentioned above, are focused principally on the processing and mechanical response of polymers reinforced with natural fibers, without considering that their mechanical properties decrease after exposition to alkaline environmental of cement materials or weather. Natural fibers reduce their mechanical properties after exposition to alkaline environment of the cement matrix, nevertheless the use of polymeric matrix as a binder aroimd the natural fibers provides protection for them. However, if the interface of composites is not good, and/or matrix is not alkaline resistant, hydration products like calcium hydroxide will migrate to interface, and polymer composite will deteriorate. Several studies have demonstrated that the mechanical properties of natural fibers decrease after exposure to alkaline environment of the cement matrix due to three different mechanisms [30-39] ... 

Processing techniques used for basalt fibers are similar to the traditional techniques used for glass fibers (fabric, filament, staples, glass fiber-reinforced polymer [GFRP]). Thanks to their excellent properties, basalt fibers are employable in heat-resistant as weU as alkaline-resistant products (containers, pipes, GFRP, materials for thermal insulation). 

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