ISSN:0022-233X    

DOI:10.1080/10601326708053766

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Various azomethine monomers, including some new Schiff bases, azines, and ketanils have been prepared in high yields by a simple, continuous azeotropic method.

ISSN:0022-233X    

DOI:10.1080/10601326708053767

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The amine moiety in Schiff bases can be exchanged quantitatively by another amine to yield new Schiff bases if the volatility of the replacing amine is lower than the derived amine, thereby allowing the latter to distilled from the reaction mass. This amine exchange was shown to be quantitative also for diamines and di-Schiff bases. Similarly, quantitative conversions were found for aldehydes and acetal exchanges with Schiff bases for both monofunctional and difunctional reactants. The bis exchange, involving two complementary Schiff bases, was quantitative also when the reactants were so selected that one of the new derived Schiff bases could be removed by distillation. The bis exchange was demonstrated with mono and di-Schiff bases.

ISSN:0022-233X    

DOI:10.1080/10601326708053768

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The acetals of aryl aldehydes react with aryl amines to produce Schiff bases in quantitative yields. This reaction was also facile with diamines and diacetals. It involves a two-step elimination of alcohol; kinetic data indicate thatk2is equal to or greater thank1and this complicates the isolation of any intermediate compound.

ISSN:0022-233X    

DOI:10.1080/10601326708053769

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The four isomeric Schiff base polymers, poly(p-xylylidene-p-phenylenedi-amine), poly(p-xylylidene-m-phenylenediamine), poly(m-xylylidene-p-phenylenediamine), and poly(m-xylylidene-m-phenylenediamine) were synthesized by the bis-Schiff base exchange reaction from the appropriate pairs selected from the four monomers, N, N'-bisbenzylidene-p-phenyl-enediamine, N, N'-bisbenzylidene-m-phenylenediamine,p-xylylidenedianil, andm-xylylidenedianil. The differences in the thermal stabilities in nitrogen and in air of these four isomeric polymers prepared by condensation to temperatures of 400 and 600°C are minor.

ISSN:0022-233X    

DOI:10.1080/10601326708053770

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The synthesis of black, high molecular weight polymeric Schiff bases directly from aryldiamines and aryldialdehydes by two methods is described. The first method utilizes benzylideneaniline as the reaction medium. The second method is a direct one-step synthesis involving the reaction of the aryldiamine, aryldialdehyde, aniline, and benzaldehyde. The thermogravimetric analyses of the polymers thus prepared compared favorably with similar polymers prepared by the bis-Schiff base exchange method.

ISSN:0022-233X    

DOI:10.1080/10601326708053771

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Thermogravimetric analyses of poly(p-xylylidene-p-phenylenediamine) in nitrogen, helium, and air yield stability values substantially identical to values obtained from tests in vacuo. The respective thermal stability values in nitrogen and in air are unchanged over a fourfold change in gas flow rates. Slightly lower values are found at heating rates of 5–15°C/min than at 30°C/min. Thermal stabilities are lower in oxygen than in air, but the values are still relatively high. Higher apparent thermal stability values are observed when a powder sample of 10 mg is evaluated as a single mass rather than as a fine powder. Calorimetric measurements indicate that Schiff base polymers which have been heated in nitrogen to 1000–1200°C have not been converted to graphite-type polymers. The Schiff base polymers are resistant to radiation; their stability is shown to be independent of dose rate and of the nature of the ionizing radiation.

ISSN:0022-233X    

DOI:10.1080/10601326708053772

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0022-233X    

DOI:10.1080/10601326708053773

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0022-233X    

DOI:10.1080/10601326708053774

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0022-233X    

DOI:10.1080/10601326708053775

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor