摘要:

AbstractA series of soluble aromatic polyesters (polyarylates) containing arylene sulfone ether linkages and having inherent viscosities of 0.36–1.10 dl/g were prepared by the two‐phase low temperature polycondensation of 4,4′‐[sulfonyl‐bis(p‐phenyleneoxy)]dibenzoyl chloride and 3,3′‐[sulfonylbis(p‐phenyleneoxy)]‐dibenzoyl chloride with various bisphenols in an organic solvent‐aqueous alkaline solution system in the presence of a phase transfer catalyst. Bisphenols 4,4′‐[sulfonylbis(p‐phenyleneoxy)]diphenol and 3,3′‐[sulfonylbis(p‐phenyleneoxy)]‐diphenol were synthesized in quantitative yields by an improved procedure. The aromatic polyesters prepared were characterized by infrared spectroscopy, elemental analysis, solution viscosity, thermogravimetric analysis, differential scanning calorimetry and X‐ray diffraction. The polyesters prepared had glass transition temperatures in the range 150–230°C and initial decomposition temperatures of 397–491°C. They gave transparent, tough and flexi

ISSN:0959-8103    

DOI:10.1002/pi.4990290402

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractHigh density poly(ethylene) was grafted with butyl acrylate using benzoyl peroxide as free radical initiator in an inert atmosphere and toluene as solvent. Reaction time, temperature, initiator concentration and ratio of monomer to polymer were varied to study their effects on percentage grafting and grafting efficiency of butyl acrylate on to HDPE. The graft copolymers were characterized by IR spectroscopy and thermal analysis.

ISSN:0959-8103    

DOI:10.1002/pi.4990290403

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractPolyesters were synthesized from the following acid dichlorides: terephthaloyl (I),p‐phenylenediacetyl (II), andp‐phenylenedi(oxyacetyl) (III) and bisphenol A as diphenol under phase transfer conditions. Quaternary ammonium and phosphonium salts were used as phase transfer catalysts in a 1,1,2,2‐tetrachloroethane/NaOH system. Polyesters were characterized by IR and1H NMR spectroscopy, and elemental analysis. The influence of the catalysts and the reaction time were evaluated by the yields and ηinh values. The influence of the nature of the acid dichloride was higher than that of the catalysts due principally to the aliphatic character of the acid dichloridesII

ISSN:0959-8103    

DOI:10.1002/pi.4990290404

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractChlorinated polyesters were synthesized from the following acid di‐chlorides: 2,3,5,6‐tetrachloro‐1,4‐terephthaloyl (I), 2,3,5,6‐tetrachloro‐1,4‐phenylenediacetyl (II), and 2,3,5,6‐tetrachloro‐1,4‐phenylenedi(oxyacetyl) (III), and bisphenol A, under phase transfer conditions, using several ammonium and phosphonium salts as catalysts and a biphasic CH2Cl2/NaOH system. The influence of the nature of the catalysts and the reaction times were evaluated by the yields and ηinh of the polyesters. The reactivity of the monomers wasI

ISSN:0959-8103    

DOI:10.1002/pi.4990290405

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractSeveral polyamideimides have been synthesised by the interaction of a number of aromatic diamines with an imidedicarboxylic acid. Since these polymers incorporated a preformed imide group, they did not pose the common problems encountered in imidisation of polyamic acids. They were synthesised by low temperature (<5°C) polycondensation, in 75–92% yields and had viscosities in the range 0.18–0.39 dl/g. They were characterised by IR spectra, elemental analysis, X‐ray and thermal methods, and possessed very high solubility in polar aprotic so

ISSN:0959-8103    

DOI:10.1002/pi.4990290406

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractThe degradation behaviour of Kodar [poly(1,4‐cyclohexylene dimethyl‐eneterephthalate)] was investigated in air using thermogravimetry, differential thermal analysis and wide angle X‐ray diffraction studies. The rates of crystallization and degradation were influenced by thermal exposure and polychromatic irradiation (Λ>290 nm) for different time intervals. The crystallinity changes (Xc%) and activation energies (ΔE) for the systems have been det

ISSN:0959-8103    

DOI:10.1002/pi.4990290407

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractSemi‐interpenetrating polymer networks (semi‐IPNs) were prepared by crosslinking castor oil in the presence of chlorinated rubber. Crosslinking in toluene solution was effected with 2,4‐toluene diisocyanate or hexamethylene diisocyanate at various NCO/OH ratios. The semi‐IPNs were obtained as tough films and were characterized by their mechanical, thermal, morphological and electrical pro

ISSN:0959-8103    

DOI:10.1002/pi.4990290408

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractLow reaction rates and distinct transition phenomena from the solid to the melt state restrain solid state polymerisation (SSP) reactions of nylon salts for industrial application. To alleviate these problems, catalysts containing nylon salts are employed. In this study, hexamethylenediammonium adipate (HMA) particles were used containing a strictly controlled amount of catalyst, either phosphoric acid, sulphuric acid or boric acid. The results show considerable acceleration of the reaction rate, especially in the presence of boric acid, while the solid state character of the process is maintained throughout the total course of the reaction. Comparative polymerisation runs were monitored both by end‐group and quantitative water determinations of the reacting material to exclude any accumulation of the water of polycondensation within the reacting particles. The results obtained support further the mechanism proposed for the transition solid‐melt in SSP runs of nylon salts in the absence of catalysts. In the latter case extended water accumulation is the r

ISSN:0959-8103    

DOI:10.1002/pi.4990290409

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractA new method for characterizing conducting polymers, based on thin layer chromatography, is evaluated. Polypyrrole and polyaniline were used as the stationary phase and molecular probes were used to characterize favourable interactions on the polymers. Amino acids were chosen as the molecular probes because of the range of properties they exhibit and because there are numerous methods for their detection. Some difficulties were experienced in preparing stationary phases with suitable physical properties. However, once this was overcome, useful information was obtained with inverse TLC. Polypyrrole and polyaniline were both found to behave predominantly as anion‐exchange material

ISSN:0959-8103    

DOI:10.1002/pi.4990290410

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY

摘要:

AbstractSamples of divinylbenzene (DVB)‐styrene copolymer were prepared by free radical polymerization using benzoyl peroxide as initiator. The samples were fractionated and characterized using a light‐scattering technique. The expansion and branching factors were calculated from the light‐scattering data for the branched copolymer and standard linear samples of the same total molecular weight and were found to be comparable with literature

ISSN:0959-8103    

DOI:10.1002/pi.4990290411

出版商:John Wiley&Sons, Ltd    

年代:1992

数据来源: WILEY