Hydroxyl-Terminated Polybutadiene-Based Polyurethane Networks as Solid Propellant Binder-State of the Art

摘要

The following is the summary of the paper: 1) The network parameters of HTPB -based polyurethane networks can be modeled using functionality distribution and the extent of the cure reaction arrived at using certain judicious assumptions. Close agreement between the calculated and experimental parameters endorses the correctness of the present approach. 2) The α-model approach developed for unfilled urethane networks can be satisfactorily extended to prediction of HTPB-based solid propellant characteristics. 3) From CLDs derived from various methods, all three types of crosslink concentrations (viz., true chemical, permanently entangled, and temporarily entangled types) can be individually estimated. 4) Rheokinetic parameters can be deduced from viscosity buildup data during the cure reaction. The rheokinetic parameters can be correlated to structural characteristics of the base polymer and reactivity of the functional groups. Such correlations can be adopted to predict the viscosity buildup and pot life of the curing binder mixture. 5) A bicurative system comprising fast- and slow-reacting isocyanates can be adopted to achieve a convenient pot life with favorable propellant liner interface properties.