摘要:

The polymer literature now includes more than 500 papers dealing with cyclopolymerization and cyclopolymers, the first having appeared in 1957. A wide variety of dienes have been shown to undergo cyclopolymerization. In fact, almost all of the 1,6-dienes corresponding to the well-known vinyl monomers have now been synthesized and studied. Many of the corresponding 1,5-dienes which lead to five-membered rings on cyclopolymerization have also been synthesized and studied. In addition, both homopoly-mers of 1,4-dienes, which lead to bicyclic structures, and copolymers of 1,4-dienes with monoolefins have been synthesized and studied. Essentially all known methods of initiation of vinyl polymerization have now been used in conjunction with specific dienes in cyclopolymerization. In fact, one monomer, 2,6-diphenyl-l, 6-hexadiene, has been shown to undergo cyclopolymerization to form essentially the same polymer by anionic, radical, cationic, and coordination initiation.

ISSN:0022-233X    

DOI:10.1080/00222337108061021

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The synthesis of cis- and trans-1,3-diisocyanatocyclohexane is described. With water the cis-diisocyanate gave a bicyclic urea and a polyurea, which decomposed on heating to the bicyclic urea, and the trans-diisocyanate formed a polyurea. cis-1,3-Diisocyanatocyclohexane was polymerized using sodium cyanide as initiator to give soluble polymers which contained little or no residual isocyanato groups and hence cyclopolymerization had occurred. The polymers were thermally unstable and depolymerized quantitatively to monomer in the temperature range 270-370°. Two different structural units are possible for the cyclopolymer and the proportions of each unit were estimated by a quantitative aminolysis using di-n-butylamine. trans-1,3-Di-isocyanatocyclohexane did not polymerize under similar conditions.

ISSN:0022-233X    

DOI:10.1080/00222337108061022

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The synthesis of cis-1,3-diformylcyclohexane by a hydride reduction of the dimethyl ester of cyclohexane-cis-1,3-dicarboxylic acid is described. An inversion of configuration occurred during an attempt to prepare trans-l,3-diformylcyclohexane by a similar route, cis-1,3-Divinylcyclohexane was prepared by a Wittig reaction on the corresponding dialdehyde. Polymerization of cis-1,3-diformylcyclohexane using a cationic catalyst gave high yields of thermally unstable polymers. Soluble fractions of the polymers contained some residual aldehyde groups. Spectroscopic data confirmed that these polymers contained 3-oxabicyclo[3,3,1] nonane rings formed through a cyclopolymerization mechanism. Polymerization of cis-1,3-divinylcyclohexane using a Ziegler catalyst resulted in soluble polymers containing little residual unsaturation. This soluble polymer, from the evidence, is a cyclopolymer containing bicyclo[3,3,1] nonane units.

ISSN:0022-233X    

DOI:10.1080/00222337108061023

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The preparation of cis- and trans-1,3,5-triisocyanatocyclohexane is described. The coupling constantsJAB,JAX> andJBX were obtained from the NMR spectrum of the cis-isomer. Both isomers were polymerized using sodium cyanide in N,N-dimethylformamide as initiator. The evidence indicated that cyclopolymerization had occurred and, in both cases, predominantly bicyclic structures obtained.

ISSN:0022-233X    

DOI:10.1080/00222337108061024

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A new synthetic route to N, N'-disubstituted-N, N'-divinylureas is described. The method involves the preparation of the disodium salts of N, N'-disub-stituted ureas, their conversion to the corresponding di-(β-dimethylaminoethyl) derivatives and the application of the Cope or the Hofmann reaction to these. 1,3-Divinylimidazolid-2-one (Va), l,3-divinylhexahydropyrimid-2-one (Vb), and N, N'-diphenyl-N, N'-diviflyIurea (Vc) have been prepared by this route. The two cyclic N, N'-divinylureas (Va and Vb) were polymerized, using a radical initiator, to heavily cross-linked polymers containing a significant proportion of residual N-vinyl groups. There is no apparent evidence from IR spectra for the bicyclic units which would be present if any cyclopolymer-ization had occurred. The diphenyl compound (Vc) could not be polymerized under a variety of conditions and initiators. An explanation is suggested for the inability of Va and Vb to cyclopolymerize.

ISSN:0022-233X    

DOI:10.1080/00222337108061025

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Allyl allyl sulfonate (AAS) has been polymerized under the influence of azobisisobutyronitrile to low molecular weight polymers containing cyclic structures. This is in contrast to the behavior of allyl ethane sulfonate (AES) and of propyl allyl sulfonate (PAS) which did not polymerize under the same conditions. AAS has been copolymerized with styrene, methyl acrylate, and vinyl acetate. The following copolymerization reactivity factors have been found:

ISSN:0022-233X    

DOI:10.1080/00222337108061026

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Telomerization of allyl ethene sulfonate (AES) in the presence of butyl mercaptan yielded a mixture of two products: the first was a five-membered ring sultone containing a sulfide group and the second a five-membered ring sulfonium salt formed by reactionofthe sultone of theJustproduct with its own sulfide function. If cyclotelomerizations and cyclopolymerizations give the same ring structures, these results indicate that the cyclic units in poly-AES are five-membered rings. Telomerization of allyl allyl sulfonate (AAS) in the presence of butyl mercaptan yielded a mixture of two products formed by addition of butyl mercaptan to one of the two allyl functions. Telomerization of AAS in bromotrichloromethane yielded a small amount of 1,5-hexachIoro-3-bromopentane formed via fission of an oxygen-carbon bond, and a rearranged adduct. The rearrangement of the allyl group to a propenyl group in the case of AAS was not observed when allyl ethane sulfonate or propyl allyl sulfonate were telomerized under the same conditions. Therefore a mechanism is proposed in which the rearrangement of the allyl double bond in AAS is due to the presence of a second double bond in the same molecule. This observation also indicates that poly-AAS might have a more complicated structure than expected from a simple cyclopolymerization mechanism.

ISSN:0022-233X    

DOI:10.1080/00222337108061027

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A method based on the analytical evaluation of residual unsaturations and on the knowledge of the cyclization ratios is presented for the determination of the cyclopolymer composition in terms of structural units. The application of this method to the products of the free radical polymerization of vinyl-transcrotonate and of divinyl ether is described.

ISSN:0022-233X    

DOI:10.1080/00222337108061028

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The purpose of this investigation was to prepare suitable solid 1,6-dienes and the corresponding monoenes and to compare their UV and NMR spectra. A comparison of their polymerization characteristics will be reported in the succeeding paper of this series. The compounds chosen for this study were dimethacrylamide, N-isobutyrylmethacrylamide, and their N-methyl and N-phenyl derivatives. Since the dimethacryl derivatives are solids at room temperature, they are suitable monomers for solid-state polymerization studies, the results of which could lead to significant conclusions regarding the fundamental basis for cyclopolymerization. A previously postulated electronic interaction between the neighboring double bonds of the dienes should be detectable when their UV spectra are compared with their monoene counterparts. The UV spectra of the N-isobutyrylmethacrylamides and dimethacrylamides were compared with the spectra of the related di-isobutyramides, methacrylamides, and isobutyramides. The spectra of the diacylamides were much more complicated than predicted, and it seems that interaction of the carbonyls through the nitrogen is the major factor affecting the observed spectral transitions. This is different from the corresponding anhydrides in which the carbonyl groups appear to behave as isolated chromophores. The NMR spectra of the compounds were determined since a comparison of chemical shifts and variations of chemical

ISSN:0022-233X    

DOI:10.1080/00222337108061029

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The purpose of this investigation was to study the solid-state polymerization of suitable 1,6-diene monomers, to compare the structure of the polymers with those obtained by free radical initiated solution polymerization, and to use this information in postulating the most probable conformation of the monomer in the crystal. An additional purpose was to compare the polymerization characteristics of these dienes with suitable monoolefinic counterparts. The compounds studied were dimethacrylamide, N-isobutyryl-methacrylamide, and their N-methyl and N-phenyl derivatives. Solution polymerization of all monomers and solid-state polymerization of solid monomers (N-methyl- and N-phenyl-N-isobutyrylmethacrylamide were liquids which did not polymerize) led to polymers of comparable structure in each case. Dimethacrylamide yielded a polymer consisting primarily of six-membered rings. N-Methyldimethacrylamide gave a polymer consisting predominantly of five-membered rings but up to 30= six-membered rings. N-Phenyldimethacrylamide gave a polymer containing almost exclusively five-membered rings. The formation of comparable cyclic polymers by both methods is interpreted to mean that the 1,6-diene molecules are present in the crystal in a conformation favorable for cyclopolymerization.

ISSN:0022-233X    

DOI:10.1080/00222337108061030

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor