Synthesis and Characterization of Glycidyl Azide Polymers Using Isotactic and Chiral Poly(epichlorohydrin)s

Abstract

Isotactic and chiral glycidyl azide polymers (GAPs) have been synthesized by the reaction of isotactic and chiral poly(epichlorohydrin)s (PECHs) with sodium azide in dimethylformamide at 95 °C. The azidation does not affect the isotacticity of the chains, 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 isotactic and chiral PECHs used as starting materials for the GAP syntheses have been prepared by the Vandenberg process using racemic or chiral monomers, leading thus to partially ((RS)-PECH) or completely ((R)- or (S)-PECH) isotactic 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 isotactic 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.

Copper‐Free Synthesis of Glycidyl Triazolyl Polymers

“…The peaks of the glycidyl carbons (a, b, and c) were assigned based on our previous study . The carbon (a) showed multiple peaks because GTP was synthesized from an atactic polyepichlorohydrin b).…”

Synthesis and characterization of [60]fullerene-poly(3-azidomethyl-3-methyl oxetane) and its thermal decomposition

“…As C 60 has good features such as thermal stability, antioxidation, etching resistance, good compatibility with propellant components, and beneficial for preventing aging. [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Usually, azide energetic material has higher thermal stability [27][28][29][30][31][32][33] and the thermal decomposition of azido group was ahead of the main chain and independent, which can help increase the energy and accelerate the decomposition of the propellant. [6][7][8][9][10][11] If some energetic groups, such as nitro group (-NO 2 ) and azido group (-N 3 ), were incorporated in the [60]fullerene cage, then a better fuel additive may be obtained.…”

A Facile Strategy for the Preparation of Azide Polymers via Room Temperature RAFT Polymerization by Redox Initiation

“…According to the literatures, azide polymers are commonly prepared by chemical modification of polymers in biphase using sodium azide and chlorinated polymers, [3,9,[20][21][22] and some are obtained by living cationic ring-opening polymerization of cyclic ether azides. [5][6][7][8][9][10][11] However, it is well known that azido content in the polymer produced by chemical modification could not be controlled very well, and ionic polymerization requires stringent reaction conditions such as high purity of monomers and high vacuum techniques.…”