Method of producing thermoplastic elastomers having alternative crystalline structure for use as binders in high-engergy compositions

Abstract From the Canadian patent

A method is provided for synthesizing block polymers which are thermoplastic elastomers. The thermoplastic elastomers are useful as binders in high-energy compositions such as propellants, explosives, gasifiers or the like. The block polymers have both (A) and (B) blocks; the A blocks being crystalline at temperatures below 60°C and the B blocks being amorphous at temperatures above -20°C. Both the A and B blocks are polyethers formed from monomers of oxetanes and/or tetrahydrofuran. To prepare the block polymers the (A) and (B) blocks are, separately prepared and separately end-capped by reacting each block with a diisocyanate in which one of the isocyanate moieties is substantially more …