摘要:

AbstractThe electron absorption spectra and the electrical conductivity of two systems: 1.1‐diphenylalkyllithium/tetrahydrofuran and the dilithium compound of 9.10‐dialkyl‐9.10‐dihydroanthracene/tetrahydrofuran were studied. The investigations were carried out over a wide range of concentrations of the organolithium compounds, covering both the region of predominant ion pairs and that of high relative free ion content, according to conductometric data. It is shown for both systems studied that the electron absorption spectrum remains practically unchanged when passing from ion pair to fr

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520101

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractMagnetic bond anisotropy effects on the chemical shifts of linear hydrocarbons were calculated for the terminal methyl and the methylene protons of planar zigzag chains with a number of carbon atoms from 3 to 22. It was found that the methylene protons near the chain end appear at a slightly higher field than these at the middle of the chain, and approach an asymptotic value at lower carbon numbers comparing with those of the middle point. It may be proposed that the tendencies of the observed chemical shifts of some linear hydrocarbons in α‐chloronaphthalene may be interpreted by the existence of some extended conformations of the chains in this solve

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520102

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe proton decoupled natural abundance13C (designated as13C‐{1H}) high resolution nuclear magnetic resonance spectra were measured for polypropylene at 25.1 MHz. The samples used were 4 polymers of different tacticity. The spectra of methylene carbon split corresponding to diad and partially tetrad placements. The spectra of methyl carbon of stereoblock type polymer clearly split corresponding to pentad placements. These splittings were tentatively assigned. The relation between the relative intensities of pentad placements, namely,\documentclass{article}\pagestyle{empty}\begin{document}$$ 2\left( {mrrm} \right) + \left( {mrrr} \right) = \left( {rmrr} \right) + \left( {mmrr} \right) $$\end{document}was not satisfied. As the causes of this inequality, several possibilities were pointed out.The triad microtacticity of highly isotactic polymers determined from13C‐{1H} spectra were compared with the results ofn‐heptane extraction and good correspondence within experimental error were obtained. The discrimination of configurational sequences of polypropylene by13C‐{1H} spectra at 25.1 MHz is equal or superior to that possible in1H spectra at 220 MHz. However, the two peaks assigned to methine carbon showed abnormal inte

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520103

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe acid‐catalyzed condensation of formaldehyde and diphenyl sulfide was carried out in benzene in the presence ofp‐toluene sulfonic acid. From the products, four poly(methylene diphenyl sulfides) of the following structures were isola

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520104

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractKinetic studies on the acid‐catalyzed reaction of formaldehyde with diphenyl sulfide (DPS) were carried out in acetic acid in the presence of sulfuric acid. The rate of the initial stage of the reaction was found to be in agreement with the following equation.\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm v } = \frac{{ - {\rm d}\left[ {{\rm CH}_2 {\rm O}} \right]}}{{{\rm dt}}} = {\rm k}\left[ {{\rm H}^ \oplus } \right]\left[ {{\rm DPS}} \right]\left[ {{\rm CH}_2 {\rm O}} \right] $$\end{document}The relative rates of diphenyl sulfide and its homologous compounds in the reaction with formaldehyde gave a good correlation with BROWN‐OKAMOTO's σ⊕values and a large ρ value. The polar effects of substituents of the substituted diphenyl sulfides on the rates were found to be considerably large. From these results a plausible mechanism of the reaction has been

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520105

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractPoly(acrylonitrile) was modified to give products of the form below via reaction with hydroxylamine and subsequently with group IV organometallic reactants:The products obtained with Cl2MR2are crosslinked. Properties of the new polymers are briefly characterized.

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520106

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe synthesis of cross‐linked polyesters from the condensation of poly(acrylic acid) with Group IV B dicyclopentadiene dichloridesviathe interfacial and solution techniques is described. The polyesters are believed to contain the following repeating units:Thermal properties of the polyesters were studied by Differential Scanning Calorimetry and Thermal Gravimetric Analysi

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520107

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractPolymers of the below form are synthesizedviathe interfacial polycondensation route.A study has been made of the influence of the nature of the solvents employed and base and reactant concentration. New interfacial solvent systems are presented.

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520108

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractPoly[alkylene(arylene)oxystannanes] of the form below have been synthesized from dichlorostannanes and diols using a modified nonaqueous interfacial system consisting of acetonitrile and hydrocarbons.The products are preferentially capped with alcohol end‐group

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520109

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY

摘要:

Abstracthave been prepared and their structure confirmed by elemental, infrared and mass spectrometric analysis. In view of their proposed use as antioxidants, solubilities in toluene were measured, and all the compounds were subjected to thermogravimetric analysis in atmospheres of air and nitrogen. The higher mol. wt. novolak materials undergo some form of condensation reaction at moderately elevated temperatures. This reaction could have some relevance to their properties as antioxidants and is also of interest with respect to the behaviour of novolak materials in the hardening of phenolic resins.

ISSN:0025-116X    

DOI:10.1002/macp.1972.021520110

出版商:Hüthig&Wepf Verlag    

年代:1972

数据来源: WILEY