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Rheological changes during the polymerization of polyurethane based interpenetrating polymer network(IPN)
Author(s) -
Lee Y. M.,
Yang Y. S.,
Lee L. J.
Publication year - 1987
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.760271004
Subject(s) - polyurethane , materials science , polyester , rheology , viscosity , polymerization , polymer , gel point , styrene , intrinsic viscosity , polymer chemistry , interpenetrating polymer network , chemical engineering , copolymer , composite material , engineering
Experimental results on reactions forming polyurethanes and polyurethane‐polyester Interpenetrating polymer network (IPN) are discussed with particular interest in rheological and kinetic changes before the gel point. In the IPN formation, viscosity rise is affected by the amount of styrene and polyester in the reaction system. Plots of reduced viscosity vs. conversion do not fall into a single curve. The results may be explained by the concept of having intra‐molecular reaction or ring formation. The existence of hydroxyl group at the end of polyester molecule causes the graft reaction between the polyurethane phase and the polyester phase, which may speed up the viscosity rise of the reactive system. A simple method which based on rheological measurements only is proposed. This method of plotting reduced viscosity vs. reduced reaction time provides similar results as in the plots of reduced viscosity vs. conversion.