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Chemorheology of poly(urethane/isocyanurate) formation
Author(s) -
Sun Xiudong,
Toth James,
James Lee L.
Publication year - 1997
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11655
Subject(s) - isocyanate , materials science , differential scanning calorimetry , viscosity , diffusion , polymer , polymer chemistry , intrinsic viscosity , kinetics , polyol , polyurethane , chemical engineering , volume (thermodynamics) , composite material , thermodynamics , physics , quantum mechanics , engineering
Poly(urethane/isocyanurate) is a major resin used in the structural reaction injection molding (SRIM) process. In this study, the kinetics and viscosity changes of a poly(urethane/isocyanurate) resin were investigated by the adiabatic temperature/viscosity rise method and differential scanning calorimetry. The effect of the catalyst concentration and the volume ratio of isocyanate to polyol was investigated. It is found that isocyanate trimerization depends on the diffusion effect resulted from the urethane formation. A kinetic model including the diffusion effect is developed, which is able to predict the experimental results. The reaction induced viscosity rise depends on the concentration and the molecular weight of the formed polymer. The measured adiabatic viscosity rise correlates well with the calculated molecular weight growth using the recursive method.