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Synthesis of GAP‐PB‐GAP Triblock Copolymer and Application as Modifier in AP/HTPB Composite Propellant
Author(s) -
Vasudevan V.,
Sundararajan G.
Publication year - 1999
Publication title -
propellants, explosives, pyrotechnics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.56
H-Index - 65
eISSN - 1521-4087
pISSN - 0721-3115
DOI - 10.1002/(sici)1521-4087(199910)24:5<295::aid-prep295>3.0.co;2-8
Subject(s) - copolymer , polybutadiene , ammonium perchlorate , materials science , polymer chemistry , propellant , epichlorohydrin , divinylbenzene , hydroxyl terminated polybutadiene , telechelic polymer , polymerization , composite number , composite material , polymer , chemistry , styrene , end group , organic chemistry
A new triblock copolymer polyglycidylazide‐ block ‐polybutadiene‐ block ‐polyglycidylazide (GAP‐PB‐GAP) has been synthesized. The synthesis was done by cationic ring opening polymerization of epichlorohydrin (ECH) with HTPB as the alcohol and boron trifluoride etherate as the catalyst followed by the conversion of the ‐CH 2 Cl group into ‐CH 2 N 3 group. The presence of the azido groups in the GAP polymer chain makes it more energetic and the triblock copolymer can be used as an energetic binder/additive for propellant energy modification. Since the triblock copolymer has polybutadiene (PB) as the central block, which is from HTPB itself, it can be used as an additive in HTPB based polymeric formulations to improve their properties. In the present work, a part of HTPB, the propellant binder in ammonium perchlorate (AP)/HTPB propellant was removed and replaced with the GAP‐PB‐GAP copolymer. Burn rate, mechanical properties, and heat of combustion properties of these propellants were measured and compared with the unmodified HTPB/AP propellant. The results show that the burn rate of the HTPB/AP solid propellant could be enhanced by the addition of the triblock copolymer.