摘要:

Abstract2‐(2‐Hydroxy‐5‐vinylphenyl)‐2H‐benzotriazole (9) was prepared by a seven step synthesis in about a 25% overall yield starting fromo‐nitroaniline. Diazotization in aqueous HCl gave a diazonium salt which was coupled withp‐ethylphenol to an azo‐dye which was reduced with zinc powder in sodium hydroxide solution to 2‐(2‐hydroxy‐5‐ethylphenyl)‐2H‐benzotriazole (4). This compound was acetylated and then brominated withN‐bromosuccinimide to 2‐[2‐acetoxy‐5‐(1‐bromoethyl)phenyl]‐2H‐benzotriazole (6) which was dehydrobrominated with triethylamine in acetonitrile or tributylamine in dimethylacetamide to the vinyl compound which was hydrolyzed to9. This monomer was readily homopolymerized and copolymerized with styrene and methyl methacrylate using 2,

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830201

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe photodecomposition of α‐methoxydeoxybenzoin (1) and α,α‐dimethoxydeoxybenzoin (2) was investigated both in the absence and in the presence of 1,1‐diphenylethylene. The resulting products indicate that benzoyl radicals add to the olefinic double bond (initiation of polymerization), whereas the α‐methoxybenzyl radicals generated from1do not add to the olefinic double bond (no initiation), but preferentially combine with other radicals (termination of polymerization). This reaction is largely suppressed in the case of α,α‐dimethoxybenzyl radicals generated from2owing to sequential fragmentation into inactive methylbenzoate and highly reactive methyl radicals which add to the olefinic double bond and thus contribute to

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830202

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractNew poly[(amino)amide]s (4) deriving from 1,2,4,5‐benzenetetraamine and terephthalic, isophathalic, or 2,5‐furandicarboxylic acid (2a–c) were indirectly prepared by detosylation of the corresponding new poly[(tosylamino)amide]s3, which were obtained by low‐temperature solution polymerization of 4,6‐ditosylamino‐1, 3‐phenylenediamine (1) with the dicarboxylic acid dichlorides2a–c. In a subsequent step the poly[(amino)amide]s were converted by polydehydrocyclocondensation into the heat‐resistant aromatic poly(imidazo[4,5‐f]benzimidazole)s (5) by heating in a high vacuum. The results of elemental analysis, IR and UV spectroscopy, inherent viscosity measurements, molecular weight determination (osmometry), and thermal analysis (DSC, TG) of the prepared polymers are com

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830203

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractButadiene polymerization with hydrogen peroxide resulted in the simultaneous formation of oligomers, polymers, and high polymers. Analyses of their microstructures showed that oligomers have a higher content of 1,2‐structures (28%) than the polymers (22%). The nature of the chain ends was determined with low molecular weight compounds. The content of 1,2‐units is distinctly higher in the oligomers, which shows that initiation takes place preferably in 1,2‐ and propagation in 1,4‐position. Besides hydroxyl end groups, other functional groups were detected in small quantities in the low molecular weight products: aldehydes, ketones, acids, hydroperoxides, and epoxides. These functions result from secondary reactions such as transfer, initiation, or termination reactions with alcohol releasing r

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830204

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe addition of hydroxyl groups on double bonds during the synthesis of unsaturated polyesters is studied with the help of model molecules. These are diesters of unsaturated diacids (maleic and fumaric acids) or monoesters of unsaturated monoacids (crotonic, cinnamic andp‐cyanocinnamic acids) with 1,2‐propanediol. The addition reaction take place to appreciable extents only with bis(hydroxypropyl) maleate and fumarate. The reaction is catalyzed by strong acids such asp‐toluenesulfonic acid; it is reversible and favoured by high temperatures. A mechanism is disc

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830205

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractBy means of a Wittig condensation polymerization starting from 4,4′‐azodibenzaldehyde (1) and bifunctional Wittig salts of the benzene and thiophene series (2a–c) poly(azo‐1, 4‐pheny‐leneivnylenearylene)s (3a–c) were synthesized. Analogously the model compounds6a–c, 8a–d, and10a–cwere prepared. The structures of the intensive red to brown polymers and the orange to red model compounds were proved by elemental analyses, IR‐ and electronic spectra, respectively mass spectral data for the model compounds. The thermooxidative degradation of the polymers and the electrical conductivity of the polymers and model c

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830206

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractCondensation of 4‐aminoazobenzene (1), respectively 4, 4′‐diaminoazobenzene (2), with mono‐ and dialdehydes of the benzene and thiophene series yields intensive coloured polymeric azomethines (polymeric Schiff bases) with azobenzene units, respectively model compounds. The structure of these polymers and model compounds were confirmed by elemental analyses, IR‐and electronic spectra and — in the case of the model compounds — by MS and1H NMR spectra. The electrical conductivities of the polymers and model compounds and the thermo oxidative degradations of the polymers

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830207

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe reaction of 6,6‐dimethylfulvene (1) with small amounts of sodium cyclopentadienide (Na‐CPD) gives a mixture of oligomeric products, from which 1‐cyclopentadienyl‐1,3,3,‐trimethyltetrahydropentalene (7) was isolated with 67% yield. The structure of the main product7was proved by combination of spectrosopic methods as well as by NMR spectroscopy of its dianion. A reasonable reaction mechanism is presented and supported by isolation of other dimers9and12and trimers10as well as of side products11and13. The product distribution is severely influenced by increasing the amount of Na‐CPD (favouring oligomers of type11and13) as well as by addition of

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830208

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA few unsaturated polysters prepared by melt polycondensation of maleic anhydride, phthalic anhydride, and aliphatic glycols in different proportions have been characterized. The salient features of the1H and13C NMR spectra of the polyesters and of model compounds are compared. It appears that from 15 to 20% of maleic acid residues have reacted with excess glycol to yield branching points while the remaining free olefinic double bonds have undergonecis→transisomerization almost quantitatively along the oligomeric chain

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830209

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractSolution properties of poly(A) and poly(I) solution at a mole ratio of poly(A) to poly(I) of 1/2 were studied by means of calorimetry and a modified differential scanning calorimetry (DSC) with the help of circular dichroism (CD) and ultraviolet (UV) spectral methods. It was found that the heat of mixing, ΔHM, depends sharply on the ionic strength. At [NaCl]<10−2mol · dm−3ΔHMis nearly zero. At higher ionic strength ΔHMdecreases and reaches a minimum value at [NaCl] ≈︁ 2 · 10−2mol − dm−3. Above this ionic strength ΔHMincreases again. This behavior is explained on the basis of the formation of a triplex poly(A) · poly(2I) and the transition of poly(I) from a disordered to an ordered structure with increasing ionic strength. The heat of formation, ΔH, of the poly(A) · poly(21) triplex was estimated to be ca −41 kJ per mole of base triplet. Above an NaCl concentration of 2 · 10−1mol · dm−3the triplex formation may be represented by the following scheme:\documentclass{article}\pagestyle{empty}\begin{document} $$\begin{array}{*{20}c} {{\rm Poly}({\rm A}) + 2{\rm poly}({\rm I})\ ({\rm order})} \hfill \\ {{2\Delta {\rm H}_{\rm t}\atop{-\hskip-1.5pt-\hskip-1.5pt\longrightarrow}} \quad {\rm poly}({\rm A}) + 2{\rm poly}({\rm I})\ ({\rm disorder})} \hfill \\ {{\Delta {\rm H}\atop{-\hskip-1.5pt-\hskip-1.5pt\longrightarrow}} \quad {\rm poly}({\rm A}) \cdot {\rm poly}(2{\rm I}){\rm\ triplex}} \hfill

ISSN:0025-116X    

DOI:10.1002/macp.1982.021830210

出版商:Hüthig&Wepf Verlag    

年代:1982

数据来源: WILEY