摘要:

AbstractLow molecular weight amine‐terminated monomaleimide prepolymers containing 1,3,5‐triazine groups as well as ether linkages were synthesized by reacting benzophenone tetracarboxylic dianhydride, diamines having 1,3,5‐triazine group and maleic anhydride. These reactive prepolymers are soluble in low boiling solvents such as chloroform, tetrahydrofuran etc. They were characterized by elemental analyses, IR and NMR spectroscopy, vapour pressure osmometry, and viscosity. On heating at 180–190°C these prepolymers undergo simultaneous chain extension by Michael addition reaction and crosslinking by mutual reaction between their amine‐terminated and maleimide‐terminated ends. The cured polymers are thermostable and the thermal behaviour was studied by TGA, DTA, and isothermal aging. Laminates fabricated using these prepolymers and carbon fiber as reinforcing agent were evaluated by their flexural strength and interlaminar sh

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900101

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractAniline/benzylamine‐modified epoxy resins with different molecular weights, which contain tertiary amines in the middle of the polymer chain, were synthesized by the reaction of aniline/benzylamine with epoxy resin at various molar ratios. The resulting aniline/benzylamine‐modified epoxy resins were reacted with diethylamine and subsequently reacted with 2‐ethylhexanol‐blocked toluene diisocyanate to obtain thermally crosslinkable resins which contain tertiary amines at the end and in the middle of the polymer chain. These resins were partially neutralixed with acetic acid to give thermally crosslinkable cationic resins. The resulting cationic resins were dissolved in suitable solvents and mixed with deionized water to form various emulsions. The emulsion and electrodeposition properties of these resins were studied in some detail to compare the properties of these cationic resins. The results show that the deposition yields and throwing power of the emulsions prepared from benzylaminemodified epoxy resins are higher than those of the emulsions prepared from anilinemodified epoxy resins. The emulsion having proper pH values can give a high throwing power. High throwing power is the characteristic property of these modified cationic resins. Factors determining the throwing power and deposition yield of the emulsions were also inves

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900102

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractAryl acrylic acids, e. g. furyl acrylic acid or thienyl acrylic acid are readily formed by the Knoevenagel condensation reaction of arylcarbaldehydes and malonic acid in pyridine. Esterification of these acids with methanol/sulfuric acid gives the corresponding aryl acrylic acid methyl esters in good yields. In methanolic solution these methyl esters isomerize upon irradiation (λ 280 nm). No photodimerization was observed. Kinetic data are given

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900103

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractIn connection with the study of the mechanism of antioxidant action of 6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline (ethoxyquin,I) and of its ecological responses in stabilized polymers we studied its oxidation with some selected agents and the properties of products thus obtained. The oxidation ofIwith silver oxide or lead dioxide proceeds by two main routes. One of them leads to 8‐(6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydro‐1‐quinolinyl)‐6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline (IV), which is further oxidized to the blue compound 8‐(6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydro‐1‐quinolinyl)‐2,2,4‐trimethyl‐6‐quinolone (IX). In the second route position 6 is attacked and 2,2,4‐trimethyl‐6‐quinolone (VII) is formed, which is stable under the conditions used, but is oxidized further with m‐chloroperbenzoic acid, giving rise to 2,2,4‐trimethyl‐6‐quinolone‐N‐oxide (VIII). The oxidation of ethoxyquin with potassium permanganate also gives rise to dimerIVand not to 1,1′‐bis(6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline) (III) reported in the literature. Potassium nitrosodisulfonate oxidizesIwith formation of 6‐ethoxy‐2,2,4‐trimethyl‐8‐quinolone (X). The oxidation of ethoxyquin with m‐chloroperbenzoic acid gives rise to 6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline‐N‐oxide (V) and dimerIV. NitroxideVwas obtained in the crystalline state. In the presence of acids, and particularly on the surface of silica gel it decomposes to ethoxyquin and nitroneVIII. NitroxideVis readily reduced to the starting ethoxyquin. Th

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900104

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractDivers matériaux composites à base de peuplier rétifié ou naturel et de résine polyester insaturée ont été préparés par moulage. L'influence de la granulométrie de la charge a été étudiée sur quelques propriétés physico‐chimiques (densité, reprise d'humidité, dureté) ou mécaniques des matériaux obtenus. La densité et la reprise de masse en milieu humide sont toujours plus faibles si la charge est traitée thermiquement sous atmosphère inerte. Par contre, la dureté des composites issus du peuplier naturel est plus importante. Les propriétés mécaniques sont inférieures si la charge est rétifitée.Si la charge lignocellulosique est traitée thermiquement, il est possible d'optimiser les trois paramètres: densité, reprise d'eau et propriétés mécaniques; la granulométrie optimale du peuplier est ainsi comprise entre 0,75 et 1,5 mm.Les résultats obtenus sont expliqués en tenant compte des propriétés physico‐chimiques des charges et des interactio

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900105

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractThermolabile microcapsules are formed by interfacial polycondensation in which one of the wall‐forming reactants contains azo functions. These reactants are compounds of the general structure XRNNRX (X = OH, NH2, NCO, COCl). Their properties are described in detail.Experimental details of the microencapsulation such as particle size, dependence from stirrer speed and stability of the capsules are given. An ink ribbon containing a carrier covered with dye filled microcapsules is applied for thermal

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900106

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractThe phosphination of styrene‐bromostyrene‐divinylbenzene terpolymers as a function of their textural and chemical characteristics has been studied. A small decrease of both specific area and porous volume with phosphination was observed. Chemical analysis showed the presence of side reactions like reduction of the halogen, addition on the double bond, and crosslinking reaction involving the different functional groups. The phosphorous distribution was inhomogeneous; this was attributed to a difference of crosslinking density in the beads due to the particular morphology of this type of supp

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900107

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractThere is still controversy over the relative efficiency and stabilization mechanisms of secondary and tertiary HALS. In this study the performance of secondary HALS is compared with that of corresponding hindered amines bearing various substitutents at the sterically hindered nitrogen atom. The bulk of the stabilization data concerns unpigmented polypropylene and the comparison of N‐H and N‐methyl derivatives. It is found that in PP films, PP multifilaments, PP tapes and injection molded PP plates the secondary HALS and the corresponding N‐methyl derivatives give the same performance within experimental error. The results available, so far, with PE‐HD films, PE‐HD tapes and PE‐LD films lead to the same conclusion. Saturated alkyl groups other than methyl show also comparable performance. The effect of unsaturated groups such as allyl and benzyl and of oxygen atoms (nitroxyl radicals) varies. Depending on the particular polypropylene batch used, the performance can be comparable, superior or inferior to that of the corresponding NH/N‐met

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900108

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractEthylene‐vinyl alcohol (EVAL) copolymers and ethylene‐vinyl alcohol‐vinyl acetate (EVALVA) terpolymers with different VA content were achieved by hydrolysis of ethylene‐vinyl acetate (EVA) copolymers of low vinyl acetate content. Several experimental techniques (elemental analysis, thermogravimetry, NMR and IR spectroscopy) were used for the analysis of the composition of copolymers and terpolymers. The results have been critically discussed. Kinetic aspects of the acetoxy‐hydroxide transformation of the EVA copolymers have been analysed, such as the influence of steric and neighbouring group effects on the rate of this transformation. The kinetics can be expressed by a second order kinetic equation and the acetoxy groups joined to hydroxy groups are rapidly transformed. The reaction rate depends on the vinyl acetate content; the higher the vinyl acetate content of the EVA copolymer, the higher is the rate of the transformation process. Another important conclusion is related with the dependence of the rate constant on the concentration of the EVA copolymer in the reaction, on the base of equivalent ester group conc

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900109

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractCasein was grafted with a binary mixture of acrylonitrile and n‐butyl methacrylate and cast into films. The creep behaviour of the films was studied at different temperatures and at various applied stress levels. The extension increases with the increase of applied stress at all temperatur

ISSN:0003-3146    

DOI:10.1002/apmc.1991.051900110

出版商:Hüthig&Wepf Verlag    

年代:1991

数据来源: WILEY