Degradation thermal, heat-resistant polyurethanes from

Polyurethane materials exist in a variety of forms including flexible or rigid foams, chemical resistant coatings, specialty adhesives and sealants, and elastomers. Most polyurethanes are thermoset materials they cannot be melted and reshaped as thermoplastic materials. Once the reactions have ceased the thermoset polyurethanes are cured and cannot be heat shaped without degradation. The thermal stability results from the croslinking degree of polymer chains (the crosslink density) and from the nature and frequency of repeating units within the polymer chains. 

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