Wednesday, July 10, 2013

polyurethane

A polyurethane (PUR and PU) is any polymer composed of a chain of organic units joined by carbamate (urethane) links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer (with at least two isocyanate functional groups) with another monomer (with at least two hydroxyl or alcohol groups) in the presence of a catalyst.

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Dobro

  Dobro is an American brand of resonator guitars owned by Gibson and manufactured by its subsidiary Epiphone . The term "dobro&quo...