SYNTHESIS AND CHARACTERIZATION OF GLYCIDYL AZIDE POLYMERS USING ISOTATIC AND CHIRAL POLY(EPICHLOROHYDRIN)S

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Authors
  1. Brochu, S.
  2. Ampleman, G.
Corporate Authors
Defence Research Establishment Valcartier, Valcartier QUE (CAN)
Abstract
Isotatic and chiral glycidyl azide polymers (GAPs) have been synthesized by the reaction of isotatic and chiral poly(epichlorohydrin)s (PECHs) with sodium azide in dimethylformamide at 95C. The azidation does not affect the isotaticity of the cains, but the polymer backbone is degraded in the process; a GAP of high molecular weight (100 kg/mol) is nevertheless obtained. Despite the high isotacticity of the polymer chains, the GAPs are not crystalline. Long reaction times favor the branching and/or the cross-linking of the polymer. The isotatic and chiral PECHs used as starting materials for the GAP synthese have been prepared by the Vandenberg process using racemic or chiral monomers, leading thus to partially ((RS)-PECH) or completely ((R)- or (S)-PECH) isotatic polymers, respectively. They have been split into a soluble and an insoluble fraction by acetone extraction. The fractionation of chiral PECH withdraws from the polymer the incompletely isotatic chains coming from the presence of monomers of opposite configuration in the chiral epichlorohydrin or from a defective polymerization process. The population of crystals remaining in the insoluble chiral PECH fraction is thus more homogeneous, leading to an improved crystallinity and a higher melting temperature.
Keywords
GAP (Glycidyl Azide Polymer) propellants;Insensitive munitions
Date of publication
03 May 1996
Number of Pages
7
Reprinted from
Macromolecules, vol 29, no 17, 1996, p 5539-5545
DSTKIM No
96-02956
CANDIS No
499487
Format(s):
Hardcopy;Document Image stored on Optical Disk

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