Rheological Properties of Composite Polymer Liner Based on Hydroxyl‐Terminated Polybutadiene

ABSTRACT: An experimental study to determine the dependence of the viscosity and shear stress of hydroxyl-terminated polybutadiene (HTPB) and dimeryl diisocyanate (DII) liner on curing time is presented. Viscosity and shear-stress were measured by HAAKE RheoStress 600 rheometer with parallel disks configuration at a constant temperature of 65 °C. The viscosity and shear-stress change were monitored for 8 h. Analysis of data showed that the liner viscosity and shear-stress dependency on time matched to pseudoplastic fluid model. For low shear-rates, the viscosity build-up is highest, with the logarithm of the viscosity being practically linear with time and the viscosity increases by more than two orders of magnitude for these cases. When the shear rates increase, the viscosity build-up slows down considerably with time and the viscosity is increased only by one order of magnitude.