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✦   LIBER   ✦

Process monitoring and kinetics of rigid poly(urethane–isocyanurate) foams

✍ Scribed by S. Peng; P. Jackson; V. Sendijarevic; K. C. Frisch; G. A. Prentice; A. Fuchs


Publisher
John Wiley and Sons
Year
2000
Tongue
English
Weight
164 KB
Volume
77
Category
Article
ISSN
0021-8995

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✦ Synopsis


Process temperature profiles of a two-component rigid poly(urethane-isocyanurate) foam system were studied and compared with the predictions of a onedimensional numerical simulation. This model is based on experimentally determined thermophysical properties including thermal diffusivity, enthalpy of reaction, and rate of reaction. Temperature profiles were measured at three positions within the foam and at the foam surface for mold temperatures of 25°C and 55°C. A high rate of reaction and heat of reaction, along with low thermal diffusivity, cause temperatures near the foam center to be insensitive to mold temperatures for thick samples. Thermal analysis was used for determination of thermophysical properties. Temperature-dependent heat capacity, reaction kinetics, and heat of reaction were evaluated using temperaturescanning DSC. Thermal conductivity was analyzed from steady-state heat profiles. The system reaction kinetics indicated much faster kinetics than reflected by process cure temperature profiles made using thermocouples. The simulations accurately predict experimental results, allowing determination of demold time dependence on process conditions, including feed temperature, mold temperature programming, and sample thickness.