ISSN:0022-233X    

DOI:10.1080/10601326708053976

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The Lewis acid-catalyzed polycondensation of ferrocene with phenyldi-chlorophosphine is described. Under a variety of conditions, using melt and solution condensation conditions, followed by a mild postoxidation treatment, polymers composed of ferrocenylene units interconnected by phenylphosphoryl groups are obtained. The soluble, but largely infusible, products possess number-average molecular weights up to 3500 (6000 upon subfractionation). Elemental compositions vary with reaction conditions; optimal consistency with the ideal ferrocenylene(phenyl)phosphoryl recurring unit results from use of a moderate ferrocene excess and smallest possible solvent concentrations at temperatures not exceeding 105°. Much as in previously described polyacylations of ferrocene, a minor side reaction is observed which involves rupture of the metal-to-ring bond in ferrocene with subsequent incorporation of cyclopentylene groups into the polymer. This departure, however insignificant, from the purely aromatic poly-phosphine oxide composition results in thermal and oxidative stabilities not markedly superior to those of earlier ferrocenylene-methylene polymers.

ISSN:0022-233X    

DOI:10.1080/10601326708053977

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The results of some investigations into the synthesis and characterization of a new class of oligomers and polymers, the polyselenoacetals, are described.

ISSN:0022-233X    

DOI:10.1080/10601326708053978

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The vacuum or inert-atmosphere condensation of diphenyl isophthalate and 2,2′,3,3′-tetraaminobiphenyl to poly-2,2′-(m-phenylene)-5,5′-bibenzimidazole has been investigated. Evidence from polymer and model compound (diphenylbibenzimidazole) spectral studies, elemental analysis, and analysis of volatile effluent indicates that the prepolymer formed at 260 to 300°C contains both benzimidazole and hydroxybenzimidazoline but is essentially free from phenoxybenzimidazole structures. A mechanism involving loss of phenol initially, followed by evolution of water to give benzimidazole structures, is established from experimental evidence. Polymerization in vacuum to 400°C gives the polybenzimidazole.

ISSN:0022-233X    

DOI:10.1080/10601326708053979

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The thermal decomposition of poly-2,2′-(m-phenylene)-5,5′-bibenzimidazole has been investigated at temperatures to 916°C. Mass-spectrometric thermal analysis (MTA), supported by elemental analysis of residues at various stages of a thermogravimetric analysis, was used to determine product distribution as a function of temperature. Below 550°C, the major product is water. Above 550°C, degradation of the heterocyclic structure to hydrogen cyanide, ammonia, carbon monoxide, and water begins. Hydrogen and methane probably are formed from decomposition and condensation of the carbocyclic structure. Activation energies for the formation of each major product were derived from the MTA data. The average of these is somewhat temperature-dependent but agrees within experimental error with the value of 44 ± 11 kcal obtained from isothermal kinetics. A mechanism involving initial hydrolysis of the polymer to an amine-substituted polyamide is postulated. Subsequent homolytic reactions account for formation of the major products.

ISSN:0022-233X    

DOI:10.1080/10601326708053980

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The thermal degradation of polytetrafluoroethylene oxide has been examined by the isothermal and thermogravimetric methods in the temperature range 450 to 650°C. The main components of the volatile gas are trifluoro-acetyl fluoride, carbonyl fluoride, and tetrafluoroethylene. The thermogravimetric decompositions of polytetrafluoroethylene oxide and of polytetrafluoroethylene have been compared.

ISSN:0022-233X    

DOI:10.1080/10601326708053981

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The reaction of polymerization of methylphenyldisilazanes and alkyl-phenyl-N-phenylaminosilanes under the action of alkalis at high temperature was studied. It was demonstrated that polymerization of the above compounds is accompanied by the evolution of benzene as a result of splitting off of phenyl groups from silicon atoms and of hydrogens from nitrogen atoms. When hydrogen atoms bound with nitrogen were exhausted, in the case of polymerization of symmetrical tetramethylphenyl-and dimethyl-tetraphenyldisilazanes, 1,1,3-trimethyl-1,3,3-triphenyldisilazane, and methyldiphenylphenylaminosilane, the reaction was kept going by the interaction of phenyls with the protons of the methyl groups. Polymers of a complex structure were obtained as a result.

ISSN:0022-233X    

DOI:10.1080/10601326708053982

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The authors have studied certain regularities in the three-dimensional polycondensation of oligomeric ether acids with the common formula C[CH2OC(O)(CH2)nCOOH]4, wheren= 2, 4, 8, with tri-and tetratomic silicoorganic alcohols, various glycols, and diamines. Problems have been considered relating to gel formation in systems containing oligomeric and monomeric branching units. The parameters obtained, which characterize gel formation in oligomeric systems, were compared with the values calculated in conformity with Flory's theory. Research was also carried out on the kinetic regularities of three-dimensional condensations of oligomers, and constants were calculated for the rates of esterifications and the rates of formation of the gel fraction. The thermomechanical properties of polymers were investigated during the condensation processes.

ISSN:0022-233X    

DOI:10.1080/10601326708053983

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The oligomerization of substituted phenyl glycidyl ethers was studied kinetically in the presence of dimethylbenzylamine using toluene or dioxane as a solvent. The infrared spectra of the resultant oligomers suggest that the reaction products have the internal carbon-carbon double-bond un-saturation, which is confirmed by the catalytic hydrogenation. The molecular weights of the oligomers also suggest that γ-phenoxy allyl alcohol produced by the initial reaction step, in which the γ-proton of phenyl glycidyl ether is attracted by a base, amine, reacts with other phenyl glycidyl ether and thus proceeds further, yielding the oligomer. The value of the reaction constant ρ is obtained positive for this reaction, which indicates that electron-withdrawing substituents of phenyl gylcidyl ethers increase the rate of oligomerization. A kinetic analysis shows that the proposed reaction sequence accounts for all the characteristics of the polymerization including sigmoidal shapes of monomer consumption curves, reaction rates, and induction periods.

ISSN:0022-233X    

DOI:10.1080/10601326708053984

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Radiation-induced polymerization of styrene oxide in the liquid and solid states was carried out by initiating with γ-rays from60Co and electrons from a Van de Graaff accelerator.

ISSN:0022-233X    

DOI:10.1080/10601326708053985

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor