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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.
Polyurethane dispersion, or PUD, is understood to be a polyurethane polymer resin dispersed in water, rather than a solvent, although some cosolvent may be used.Its manufacture involves the synthesis of polyurethanes having carboxylic acid functionality or nonionic hydrophiles like PEG (polyethylene glycol) incorporated into, or pendant from, the polymer backbone. [1]
After the mold has been made, a synthetic resin - such as polyurethane or epoxy - mixed with a curing agent, is poured into each mold cavity. Mixing the two liquid parts causes an exothermic reaction which generates heat and within minutes causes the material to harden, yielding castings or copies in the shape of the mold into which it has been ...
An assortment of polyurethane foam products for cushioning and insulation. Polyurethane foam is a solid polymeric foam based on polyurethane chemistry. As a specialist synthetic material with highly diverse applications, polyurethane foams are primarily used for thermal insulation and as a cushioning material in mattresses, upholstered furniture or as seating in vehicles.
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 ...
The most common RIM processable material is polyurethane (known generally as PU-RIM), [2] but others include polyureas, polyisocyanurates, polyesters, polyphenols, polyepoxides, and nylon 6. For polyurethane one component of the mixture is polyisocyanate and the other component is a blend of polyol , surfactant , catalyst , and blowing agent .
Robert A. Volz is credited with discovering the first process for making reticulated polyurethane foam in 1956 while working for the Scott Paper Company. [6] Production of reticulated polyurethane foam is a two-step process that begins with the creation of conventional (closed-cell) polyurethane foam, after which cell faces (or "windows") are removed.
Thermoplastic polyurethane (TPU) is any of a class of polyurethane plastics with many properties, including elasticity, transparency, and resistance to oil, grease, and abrasion. Technically, they are thermoplastic elastomers consisting of linear segmented block copolymers composed of hard and soft segments.