Premium
Kinetic studies on curing of hydroxy‐terminated polybutadiene prepolymer‐based polyurethane networks
Author(s) -
Singh Manohar,
Kanungo B. K.,
Bansal T. K.
Publication year - 2002
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.10719
Subject(s) - prepolymer , polybutadiene , polyurethane , activation energy , reaction rate constant , curing (chemistry) , hydroxyl terminated polybutadiene , materials science , polymer chemistry , viscosity , stoichiometry , toluene diisocyanate , composite material , chemistry , kinetics , polymer , copolymer , physics , quantum mechanics
Hydroxy‐terminated polybutadiene (HTPB) prepolymer prepared by free‐radical mechanism at Chemical Engineering Complex, Vikram Sarabhai Space Center, Thiruvananthapuram was reacted with toluene diisocyanate (TDI), a curative at varying stoichiometric ratios ( r = [NCO]/ [OH]) equal to 0.7, 0.8, 0.9, 1.0, and 1.1 at a constant temperature of 70°C. The increased rate of viscosity of polyurethane networks formed was used to calculate the rate constant. Similarly, the rate of change of viscosity of curing networks at different r values (0.7–1.1) and temperature intervals (30–70°C) was used to calculate activation energy. The results of the curing networks showed that the rate constant at r > 0.9 is constant and the rate of decrease of activation energy is lower at r ≤ 1; thereafter, it becomes quite significant. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 842–846, 2002