摘要:

AbstractThe snythesis of low molecular weight epoxy resins from various alkali metal diphenolates and 1‐halo‐2,3‐epoxyalkanes in dipolar, aprotic solvents is described. The resulting epoxy resins have no oxy‐(2‐hydroxytrimethylene)oxy groups as a consequence of a lack of mobile protons in the reaction system. The effect of various factors on the reaction course was determined by kinetic mea

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790701

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe polymerization of methyl methacrylate initiated by the system diaminomaleonitrile (DAMN)/copper ion/carbon tetrachloride was investigated. The polymerization requires the presence of these three components, and both the cupric and the cuprous ion are suitable. The initial rate of polymerization with the cuprous ion is greater than that with the cupric ion. The cuprous ion was detected in both systems. It is considered that the cupric ion is reduced to the cuprous ion by DAMN, and the cuprous ion takes part in the initiation of the polymerization.

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790702

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe formation of cyclic oligomers in the cationic polymerization of 3,3‐dimethyloxetane (1) was investigated. By means of gas chromatography coupled with mass spectroscopy, cyclic oligomers from tetramer up to nonamer (2a–f) were detected in decreasing concentration. The oligomer/polymer ratio at complete monomer consumption changes with the initiating system used. This ratio is not influenced by the initiator concentration but it increases with decreasing monomer concentration. It is proposed that the cyclic oligomers are formed by reaction of the monomer with macrocyclic oxonium ions of type5which in turn are formed by an intramolecular (temporary) termination reaction. The high preference to form cyclic tetramer is discussed in terms of the preferred polymer backbone conformation. In the polymerization of oxetane, cyclic tetramer is the most important oligomer, but, contrarily with previous reports, higher oligomers were also found to be pres

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790703

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractIntroduction of small amounts of sulfonium ions in poly(thiopropylene) (poly(propylene sulfide)) by means of triethyloxonium tetrafluoroborate was found to result in a rapid degradation reaction, first leading to low molecular weight polymers and ultimately to a mixture of low molecular weight cyclic products and propene. The reaction mixtures were analyzed by gas liquid chromatography, mass spectroscopy and, when the compounds could be isolated in sufficient amounts, by1H NMR spectroscopy. The composition of the end product mixture was shown to depend on the concentration of sulfonium ions introduced at the beginning. With low initiator concentrations (≈ 10−3mol.l−1) the main degradation product was found to be cyclic tetramer accompanied by decreasing amounts of cyclic pentamer, hexamer etc., and with high initiator concentrations (>10−2mol.l−1) the main degradation products are a mixture of dimethyl‐1,2,5‐trithiepane

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790704

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractQuinine was linked to 2‐chlorocarbonyloxyethyl methacrylate (6) by a carbonate bound. This monomer7was characterized by usual spectroscopic methods and polymerized by a radical process. The resultant polymer4was biologically tested by toxicity and immunology studies on rabbit. Polymer4was analyzed by IR and NMR spectroscopy and compared with the polymer obtained by chemical modification of poly(2‐hydroxyethyl methacrylate)

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790705

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe reactions of six substituted chlorobenzenes with sulfur were investigated, and the results were compared with the results of earlier investigations in which sodium carbonate also took part in the reactions. The effect of the amount of chlorine and of the different substituents on the reaction mechanism is discussed. The approximate structures of the cross‐linked substituted poly(phenylene sulfide)s are also give

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790706

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractSynthesis and characterization of polymeric derivatives of the folic acid antagonist, Methotrexate,N‐[4‐(N‐methyl‐2,4‐diamino‐6‐pteridinylmethylamino)benzoyl] glutamic acid (1a), a widely used antitumor agent, are described. Derivatives of poly(L‐lysine), poly(iminoethylene), poly(vinyl alcohol), and carboxymethylcellulose with various contents (3–15 mole‐%) of substituted repeating units were prepared by polymer‐analogous amidation and transesterification of the dimethyl ester of1aand withN‐[2‐(N‐methylmorpholinio)ethyl]carbodiimidep‐toluenesulfonate as coupling reagent. By nucleophilic addition reactions of the pteridinyl amino groups under mild conditions,1awas bound without cross‐linking to divinyl ether‐maleic anhydride (DIVEMA) copolymers of various molecular weights. This copolymer appeared to be of particular interest as carrier because of its established antitumor and immune‐stimulating activity.—With the exception of the poly(vinyl alcohol) derivative, all polymers containing the1aresidue are water soluble at the physiological pH range. Besides the dimethyl ester of1aused as convenient starting material for polymer‐analogous reactions, further dialkyl esters of1awere synthesized as low molecular weight model compounds for the study of the pharmacodynamic properties of polymers, substituted with1a. The polymeric derivatives of1awere purified by membrane filtration, solvent extraction, and reprecipitation; the polymers and the dialkylesters1b–dwere characterized by thin‐layer chromatography, IR, NMR, UV and mass spectra, and elemental analysis. Preliminary results of the pharmacological studies with t

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790707

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe additive effect of poly(ethylene oxide) (PEO) in the Williamson reaction between sodium phenolate and butyl bromide was investigated. Under certain conditions a remarkable rate acceleration by PEO was observed in this reaction, which is explained by the fact that a cooperative coordination of oxygen atoms of PEO with metal cations promotes ion dissociation. The relationship between the formation of a PEO‐sodium phenolate complex and the reaction rate, and also the dependency of the reaction rate on the molecular weight of PEO were examine

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790708

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractSemi‐interpenetrating polymeric networks based on polystyrene were prepared by anionic polymerisation. Factors affecting synthesis, such as composition, molecular weight of either the unattached polystyrene or the polystyrene between crosslinks, have been varied. Their effect on network formation was examined by extraction experiments and swelling measurement

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790709

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractDiethyl vinyl phosphate (1), diphenyl vinyl phosphate (2), and phenyl divinyl phosphate (3) were prepared, and their polymerization and copolymerization behaviors as well as the hydrolysis of the polymers obtained were investigated. The monomers1and2were homopolymerized to give low molecular weight polymers, probably as a result of high chain transfer reactivity to monomer. Although the monomer3gave a cross‐linked polymer, this polymerization was found to proceed mainly by a cyclopolymerization mechanism to give a polymer with a five‐membered ring unit which was readily hydrolyzed. The alkaline hydrolysis of poly(1) occurred only partly and thus pure polyvinyl alcohol was not obtained. From the copolymerizations of1and2with vinyl monomers such as vinyl chloride, the reactivities of these monomers were found to be somewhat lower than that of vinyl acet

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790710

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY