Acetylenic polyacetals

Curing of the acetylenic polyacetals to rubbery polyurethanes could be achieved with any of a number of commercially available diisocyanates, including 2,4-toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), dianisidine diisocyanate (DADI), and 4,4 -diisocyanatodiphenyl-methane (MDI). The first two diisocyanates were studied most extensively. The reactions were carried out in solution in benzene, toluene, and ethylene bromide, and in bulk. The bulk reaction, which is the only... 

The objectives of this study were to extend these synthetic methods to the preparation of low molecular weight, hydroxy-terminated polymers containing acetylenic bonds and evaluating these prepolymers in castable solid propellant formulations. Since 2-butyne-l,4-diol was commercially available, the formation of polyacetals from this glycol seemed to be an attractive route to the desired polymers. It was believed that the rigid triple bond would inhibit the cyclic acetal formation observed by the earlier workers with the lower members of the saturated glycol series. Thus, in an acetal interchange reaction a linear polymer (I) should be favored over the cyclic acetal (II) ... 

Another common method for the synthesis of polyacetals involves trans-acetalation reactions of diols with acetylenic compounds [14] or vinyl ethers [15], The reaction of bis(chloromethyl) ether with diols in the presence of pyridine to give polyacetals is not recommended since bis(chloromethyl) ether is considered highly carcinogenic [16]. 

Poly-/J-isopropyl styrene 279, 281 Poly-p-methylstyrene 279, 281 Polyacetals 279 Poly acetylenes 272 Polyacrylamide 279, 281 Polyacrylonitrile 279 Polyacrylonitrile-styrene-butadiene copolymer 279 Polyamides 144,279 Polyamide-11 271... 

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