摘要:

AbstractAnhand von Modellreaktionen von teilweise blockierten Melamin‐ und Harnstoff‐derivaten mit Formaldehyd wurde die gemeinsame Kondensation von Harnstoff, Melamin und Formaldehyd studiert. An den Modellsystemem Harnstoff/Benzoguanamin/Formaldehyd und Dimethylharnstoff/2‐Amino‐4,6‐di‐(N‐methylanilin)‐1,3,5‐triazin/Formaldehyd konnten mit Hilfe der Gelchromatographie, IR‐Spektroskopie und Thermogravimetrie chemische Brücken zwischen den Triazin‐ und Harnstoffkomponenten, also Cokondensate, festgestellt werden.Auch beim System Harnstoff/Melamin/Formaldehyd konnten durch Pikratfällung der Triazinkomponenten und Urease‐Spaltung dieses Niederschlages Cokonde

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560101

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractChlorendic anhydride based polyester (I,) tetrachlorophthalic anhydride based polyester (II), dibromoneopentyl glycol based polyester (III,) general purpose polyester (IV,) blend of dibromoneopentyl glycol based polyester with general purpose polyester (V,) chlorendic anhydride and dibromoneopentyl glycol based polyester (VI), and a blend of chlorendic anhydride based polyester and dibromoneopentyl glycol based polyester (VII) were prepared and their chemical resistance and moisture absorption studied in various reagents, acid, alkali, and water, at 25 and 65°C. It is found that the polyester (III) is the least affected in the presence of the acids. In 20% NaOH, there was a decrease in weight for all polyesters at both the temperatures compared to the control except the polyester (VII). Increase in weight of all the polyesters was observed during the absorption of moisture both at 25 and 65°C. The increase was higher at higher temperature. Polyester (III) thus shows the least absorption of moistur

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560102

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractPolymers containing urethane units were synthesized by solution polymerization of bisphenols A, C, and F with diisocyanates viz. toluene‐2,4‐diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate, respectively. Thus obtained polymers were pale yellow amorphous powders. These polymers were characterized by infrared spectral studies and nitrogen content. The number‐average molecular weights (M̄n) were estimated from conductometric titration and limiting viscosity number [η] in dimethyl formamide. From thermogravimetric analyses, the thermal behaviour was studied. Kinetic parameters for their degradation were c

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560103

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractNew diglycidyl esters coming from the corresponding diacids and epichlorohydrin were synthetized using a quaternary ammonium salt as a catalyst. The new asymmetric compounds were characterized by spectroscopic methods and employed as starting monomers in a crosslinking process. The course of the reactions was followed by IR spectroscopy. Some intermediate species were identified in the onset of the reactions by recording13C‐NMR spectra until the products became insoluble in the usual deuterated solvents. The thermal behaviour of these cured epoxy resins was also studie

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560104

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractThe reactions of cyclohexanone‐formaldehyde‐resin via its hydroxy and carbonyl functional groups with a number of different reagents such as acetic anhydride, benzoyl chloride, hydroxylamine, semicarbazide, and phenyl hydrazine were studied. Melting points, IR spectrums, and solubilities in various solvents of the products were determi

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560105

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractThe room‐temperature grafting of polyacrylonitrile (PAN) onto guaran (guar gum) in 2.5 × 10−3M aqueous sols or aqueous‐methanolic suspensions, initiated by (NH4)4Ce(NO3)6in 1M HNO3, leads to PAN‐branched polysaccharides with graft contents of 11 – 53%. Main chain degradation by treatment with boiling aqueous HCl results in detachment of the PAN side chains, for which number‐average molecular masses of ca. 15000 – 48000 are determined viscometrically with the aid of the known Mark‐Houwink relationship (K = 3.92 × 10−4, a = 0.75). Grafting frequencies are in the range of 0.004 – 0.012, equivalent to an average of 80 – 250 non‐grafted repeat units for every singly grafted unit in the guaran main chain. The graft copolymers are of interest as precursors of carboxyl‐functionalized, water‐soluble polysaccharides to serve as polymeric micronutrient and dr

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560106

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractThe separation of phases in defined multiblock (b‐styrene‐bisphenol A carbonate) copolymers was analyzed by small‐angle X‐ray scattering. It was found that these copolymers form typical microdomain structures. For copolymers containing 0.34 and 0.47 wt.‐parts polycarbonate (PC) the microdomains are arranged in the face‐centred cubic macronetwork. The distance between domains decreases with increasing concentration of polycarbonate. The copolymer containing 0.767 PC has lamellar structure. The thickness of the domain‐boundary interphase was quantitatively estimated by analyzing a systematic deviation of the scattering curves at large angle tail from the Porod's law. The thickness of the transition layer decreases with increasing concentration of

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560107

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractCarboxymethyl cellulose (CMC) was treated with HCl at 80°C for different time periods (15 – 60 min). The hydrolyzed CMC samples as well as the original sample were graft copolymerized with acrylamide using K2S2O8as initiator. It was disclosed that the increasing duration of acid hydrolysis is accompanied by a progressive increment in the copper number of CMC, meanwhile its carboxyl content decreases. Acid hydrolysis enhances significantly the susceptibility of the CMC toward grafting. The latter reduces the copper number of the hydrolyzed CMC samples most probably via conversion of the aldehydic to carboxylic groups under the action of K2S2O8during grafting. Grafting also reduces the carboxyl content of the original CMC sample while increasing those of the hydrolyzed CMC samples. Methylolation of the polyacrylamide‐CMC graft copolymers results in reactive finishes. When the latter were applied to cotton fabric according to the conventional pad‐dry‐cure method followed by a thorough washing, the fabric retained ca. 86% of the finish derived from the copolymer of CMC and 92% of finishes derived from the copolymers of hydrol

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560108

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractThe reaction of N‐phenyl‐1,4‐benzoquinoneimine(I)Decoding of abbreviations see p. 103/104.and 4‐hydroxydiphenylamine(II)with the carbon centred 1‐cyano‐1‐methylethyl radical (R·) was studied in connection with an investigation of the action mechanism of industrial antidegradants, such as N‐phenyl‐N′‐sec‐alkyl‐1,4‐phenylenediamines. The mixture ofIandIIreacts very readily with R·, giving rise toIII,VI, andVIII.Ialone reacts much slowlier, and the reaction mixture contains more products.IVandVIIwere identified along withIII. Under the conditions used,IIalone does not react at all.IVexists in two isomeric forms, syn and anti.VIIIis very labile;XIwas isolated from its transformation products. Reduction ofIVgivesV, whic

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560109

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY

摘要:

AbstractThe influence of the removal of various diluents, pore forming agents from the porous styrene‐ethylstyrene‐acrylonitrile‐divinylbenzene copolymers on the structure of the matrix was investigated by several methods. The most advantageous pathway to preserve the initial structural edifice of the porous networks performed in the presence of solvating diluents consisted in the removal of the inert media with methanol as it was noticed from the experimental data. If the steam treatment is applied, the collapse effect takes place and the anion exchangers prepared from such matrices exchange/adsorb less dye stuff by comparison with ones formed from beads treated with methanol, because the pore size was changed. It was also noticed that the porous copolymers performed in the presence of the solvating diluents (mixtures of solvatings and precipitants) swell very well in methanol though it is a precipitating medium for the polystyrenic macromolecular c

ISSN:0003-3146    

DOI:10.1002/apmc.1988.051560110

出版商:Hüthig&Wepf Verlag    

年代:1988

数据来源: WILEY