investigating the effect of molecular weight on chemorheology of hydroxyl terminated polybutadiene gum stock

Long pot life for the htpb-based gum stock (binder system) is essential to simplify the processing and manufacturing of non-defect grains, especially large size grains# the htpb microstructural parameters such as mn, mw, pdi, functionality distribution and the type and relative concentration of cis/trans/vinyl affect the kinetics of step polymerization of htpb gum stock# chemorheological behavior of binder systems based on three different number-averaged molecular weight htpb samples (htpb-a, htpb-j, and htpb-aj), dos plasticizer and tdi curing agent, is investigated using a rotational viscometer at a constant temperature of 40 ºc# in this paper, the influence of the number-averaged molecular weight of htpb on high-filled composite htpb-based binder system pot life is investigated and the possibility of controlling pot life by microstructure tailoring has been investigated# the viscosity of the curing system at any given time can be changed with respect to time as an exponential function# viscosity build-up results showed a linear relationship between number-averaged molecular weight (mn) and pot life (t) of htpb-based binder system, [t = - an mn + b] therefore, it can be said that when the mn of the htpb sample increases, the viscosity increases, resulting in a decrease in the pot life of the htpb-based binder system due to increasing of hydroxyl content#