Kinetic and Viscosity Relations for Thermosetting Polyurethanes

Autor:	A J Rojas, R. J. J. Williams, M M Reboredo
Rok vydání:	1983
Předmět:	Materials science Polymers and Plastics Kinetics Thermosetting polymer Thermodynamics Activation energy Isocyanate Viscosity chemistry.chemical_compound chemistry Polymerization Polymer chemistry Materials Chemistry Molar mass distribution Polyurethane
Zdroj:	Polymer Journal. 15:9-14
ISSN:	1349-0540 0032-3896
DOI:	10.1295/polymj.15.9
Popis:	Kinetic and viscosity relations for polyurethane network polymerization were analyzed. A rigid foam formulation consisting of a polymeric isocyanate (functionality ca. 2.7) and a polyether polyol (functionality ca. 4.5), was selected. The kinetics were studied with adiabatic temperature rise and chemical techniques. An overall second-order reaction and an activation energy, E=51.2 kJ mol−1, were obtained. The viscosity rise was correlated with the reaction extent and the weight average molecular weight. The dependence of viscosity on the latter was of mth order, with m greater than 3.4. This high parametric sensitivity is associated with the formation of branched structures from the beginning of the reaction.
Databáze:	OpenAIRE
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