ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Hydroxy-terminated polybutadiene (HTPB) liquid prepolymers (I-IX), with closely similar OH values, M̄n, viscosity, and microstructure, were synthesized by H2O2-initiated free-radical polymerization of butadiene in an isopropanol-water solvent system. However, binders obtained by curing HTPB polymers showed wide variations in their sol content, cross-link density, and mechanical properties. These variations were atributed to the differences in functionality-type distribution (FTD) and molecular weight distribution (MWD) of the polymers. FTD was interpreted in terms of -type primary hydroxyls. [V/G] showed excellent linear correlation with the elongation at break (E) of the binders. The polymers exhibited bimodal MWD and this behavior was discussed in relation to two different initiation processes occurring. The high molecular weight fraction (Fh) of the various polymers was determined by reverse-phase HPLC and showed good correlation with E. The sol content and cross-link density of the binders also showed good correlation with the parameter V/GFh. The parameters [V/G] and Fh provide acceptance criteria for blending different batches of polymers for propellant formulations. © 1993 John Wiley & Sons, Inc.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1993.070490308
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