posted on 2016-06-07, 00:00authored byGaetano Francis D'Alelio
The compounds disclosed herein are acetylenic methacrylates having the formula\u000a\u000aCH2 = C(CH3)COO-Z-C=CH\u000a\u000awherein Z represents a divalent hydrocarbon radical having at least 2 carbon atoms. Because of their terminal acetylenic radical these compounds are very reactive and capable of producing various acetylenic derivatives. Moreover, the methyl group in the methacrylate portion of the ester gives this compound much greater stability than possessed by the corresponding acrylates. This stability is particularly useful when it is desirable to produce reaction on the acetylenic group but not on the ethylenic. Moreover, the terminal acetylenic makes possible certain reactions which cannot be effected with compounds in which the acetylenic group is not a terminal group. Furthermore the presence of the methyl group in the methacrylate portion of the ester gives sufficient greater polymerization tendency, as compared with the acrylate, that the ethylenic group can be polymerized with less stringent conditions and thereby reduces the tendency for reaction of the anionic initiator with the ester group; the molecular weights and conversions are thereby higher. This increased selectivity of ethylenic polymerization over acetylenic makes it possible to prepare linear homopolymers and thereby to avoid the necessity to resort to copoly-meriaztions with monoethylenic compounds such as styrene, and monounsaturated acrylates and methacrylates.