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Polyurethane synthesis, wherein the urethane groups −NH−(C=O)−O− link the molecular units A kitchen sponge made of polyurethane foam . Polyurethane (/ ˌ p ɒ l i ˈ jʊər ə ˌ θ eɪ n,-j ʊəˈr ɛ θ eɪ n /; [1] often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links.
Moisture cure polyurethanes have been widely used in the adhesive and coating industries. Thermal, mechanical, and surface properties of hyperbranched polyurethane-urea (HBPU) moisture cured coatings have been studied in relationship to chemical structure. [3]
Spray foam insulation or spray polyurethane foam (SPF) is an alternative to traditional building insulation such as fiberglass. A two-component mixture composed of isocyanate and polyol resin comes together at the tip of a gun, and forms an expanding foam that is sprayed onto roof tiles, concrete slabs, into wall cavities, or through holes ...
A defoamer or an anti-foaming agent is a chemical additive that reduces and hinders the formation of foam in industrial process liquids. The terms anti-foam agent and defoamer are often used interchangeably. Strictly speaking, defoamers eliminate existing foam and anti-foamers prevent the formation of further foam.
The organic foam impregnating method is one of the more widely used in industry, creating the ceramic foam with a 3D mesh skeleton structure and coat a ceramic slurry on a polyurethane organic foam mesh body. The ceramic foam is obtained by allowing the body to dry at room temperature and burn the mesh body to retrieve the ceramic foam.
Therefore, water-filled bubblets will absorb more heat than the air-filled foam bubbles (which are more effective for vapor suppression). When gel is applied to a surface such as an exterior wall, the water-filled bubblets can absorb much of the heat given off by the fire, thereby slowing the fire from reaching the wall.
A seal is a device or material that helps join systems, mechanisms or other materials together by preventing leakage (e.g. in a pumping system), containing pressure, or excluding contamination. The effectiveness of a seal is dependent on adhesion in the case of sealants and compression in the case of gaskets .
They require a dry, clean surface during application to gain adhesion. Topical sealers may alter the coefficient of friction which can make substrates slick when wet – a condition that can be remedied by adding anti-skid materials. Life span is generally 1-5 years, although high-end epoxy/urethane systems can last significantly longer.