Evolution of Nonlinear Rheology during Polyurethane Polymerization

Evolution of Nonlinear Rheology during Polyurethane Polymerization 

The gel point and network formation are also identified from the frequency independence of the loss angle (tan S = G jG) at a critical reaction time or conversion [38]. Finally, it should also be mentioned that rheological properties of TPUs 

Basic Reactions and Phase Separation Kinetics in Synthesis of Poiyurethanes and Their Reiationship to the Evoiution of Noniinear Rheoiogy 

The kinetics of reactions between the monomers is a dominant parameter that impacts the rheological properties. For example, faster reactions lead to faster gelation and creation of a continuous polymer network. Another dominant parameter is the extent of phase separation. On one hand, it retards the rate of reactions and, on the other, promotes the formation of the polymer network and hence leads to an increase of viscosity. Accordingly, one may anticipate an intricate interplay between the reaction kinetics, phase separation, and network formation. 

Evolution of Nonlinear Rheology and Network Formation during Thermoplastic Polyurethane Polymerization Effects of Mixer Design, Mixing Protocol, Catalyst Concentration, and Timescales 

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