The Structure of the Polymers of α-Haloacrylates

Abstract

placed next to the flask as a source of illumination. The reaction proceeded rapidly at room temperature. After the addition was complete, the reaction mixture was washed with sodium bisulfite followed by water, dried and rectified to give principally the tetrabromo addition product along with some of the dibromo compound.Bromination of 2,7-Dimethyl-3,3,4,4,5,5,6,6-octafluoro-1 ,'l-octadiene.-This olefin was brominated in a similar manner with the exception that the reaction temperature was maintained a t the reflux temperature of the mixture. Only the tetrabromo addition product was isolated.Bromination of 5,5,6,6,7,7,7-Heptafluoro-3-heptene.-A solution of 150 g. of the olefin in 100 ml. of carbon tetrachloride was cooled to 12" and a solution of 120 g. of bromine in 100 ml. of carbon tetrachloride was added dropwise. The reaction was illuminated by a 150-watt light bulb placed next to the flask. After one-half the bromine was added, the temperature rose to 22" and hydrogen bromide was liberated. The temperature was lowered to 10' and the remaining bromine added. After standing for 12 hours a t room temperature, the reaction mixture was refluxed for two hours causing further liberation of hydrogen bromide. The solution was then washed with sodium bicarbonate followed by water, dried and rectified. Both the dibromo addition product and an olefin resulting from its dehydrobromination were obtained.Bromination of 2-Methyl-4,4,5,5,6,6,6-heptafluoro-2-hexene.-A solution of 160 g. of the olefin in 150 ml. of chloroform was placed in the flask and a mixture of 125 g. of bromine in 100 ml. of chloroform was added dropwise. No cooling was employed and the reaction temperature rose rapidly to reflux with the liberation of hydrogen bromide. After the addition was complete, the mixture was refluxed for 48 hours. The solution was then washed with sodium bicarbonate followed by water, dried and rectified. The dibromo addition product was obtained as well as two bromine substituted derivatives of the starting material.Acknowledgment.-The authors wish to express their appreciation to the Petroleum Branch, Materials Laboratory, Wright Air Development Center, Dayton, Ohio, for supporting this work. LAFAYETTE, IND.The latter material was not identified. ~~The present investigation shows that the earlier assignment of a "head-to-head'' arrangement of the monomer units it1These polymers have beeii polyalkyl a-haloacrylates was based on a misinterpretation of the reactions of these polymers. proved to have predominantly the "head-to-tail" structure.

Reductive dehalogenation of β-haloacrylic ester derivatives mediated by ene-reductases

“…Polymerization of substrates (in the presence or absence of enzymes) occurred to various extents, which is not surprising given the tendency of (a-halo)acrylates to polymerize. 33 Interestingly, polymerization was predominant with 1a in the presence of 3.5 equiv. of NADH and OYE1 or OYE2 (Table 1, entry 1).…”

Structure of synthetic high polymers

“…Proof of structure of the polymers from a-haloacrylic esters proved more difficult. Evidence originally believed (25) to support the head-to-head, tail-to-tail attachment was later shown (26) to be explainable on the basis of head-to-tail structure.…”

Cooligomerization of Sulfur Dioxide with Octene-1

“…The problem in head-to-tail structures of polysulfone has already been discussed by Kharasch 14 and Marvel. 17 The oligosulfone may give further information about this problem and be discussed in a subsequent report.…”