摘要:

AbstractA series of poly(hydrazooxalyl)s (2) is prepared by self polycondensation of oxalohydrazide (1a) and by polycondensation of various derivatives of oxalic acid with1aor hydrazine hydrate under a variety of reaction conditions. The molecular weights of the polymers were found to remain low. IR spectroscopy, X‐ray diffraction, and thermogravimetry were used to study the structure and thermal properties of the prepared polymers. The structure and properties of the polymers were found to depend largely on the monomers and the reaction conditions used in the synthesis, most polymers being partially cyclodehydrated and semicrystalline.2seems to possess an extended planar zigzag chain conformation similar to that of polyamides of aliphatic acids, although several crystalline modifications were observed for this polymer. It could also be enolized with strong bases and behaves like a polyelectrolyte in aqueous base solution

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790101

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe swelling behaviour, the time‐dependence of the uptake of Cu2+‐ions, and the pH‐dependence of the uptake of Cu2+‐, Ni2+‐, Cd2+‐, Zn2+‐ and Mg2+‐ions of crosslinked poly[1‐(4,5‐dicarboxy‐1‐imidiazolyl)ethylene] (1) and poly{1‐[p‐(4,5‐dicarboxy‐2‐imidazolyl)phenyl]ethylene} (2) were investigated. Both resins have a high selectivity for heavy metal ions. For resins1the uptake of heavy metal ions in the presence of an excess of EDTA was studied. Furthermore the possibility to remove Hg2+‐ions from aqueous alkalichloride

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790102

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractExperiments regarding the anionic polymerization of acenaphthylene with different initiators (lithiumnaphthalene complex, 1,2‐diphenylethylenedilithium, 1,1,4,4‐tetraphenyltetramethylenedilithium and butyllithium) and solvents (tetrahydrofuran and benzene) show that only short chain (P̄≈ 20) and coloured polymers with broad molecular weight distribution are obtained, because of chain transfer reactions to the monomer. A mechanism of this polymerization is proposed. By radical polymerization short chain polyacenaphthylene with definite end groups can be ob

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790103

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe kinetics of aqueous polymerization of acrylamide, initiated by the potassium persulfate(K2S2O8)/2‐mercaptoethylamine hydrochloride (MEAH) redox pair was studied under nitrogen atmosphere at 30 ± 0,1 °C. The initial rates of polymerization were found to be proportional to [K2S2O8]1,5(in the range of 0,8 to 1,2 mmol−1), to [acrylamide]1(in the range of 0,8.10−1to 1,2.10−1mol 1−1), and to [MEAH]1(in the range of 1,0 to 7,0mmol 1−1), respectively. The overall energy of activation was found to be 9,8 kcal mol−1(40kJ mol−1). Water miscible alcohols and common salts (NaF, NaCl, (CH3)4NI) appeared to depress both the polymerization rate and the maximum conversion. With MnSO4.4H2O the reverse in

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790104

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractJapanese lacquer is a sole, enzymatically drying natural lacquer, giving films with excellent durability. Oligomerization of urushiol (1) (a major component of the lacquer) in the lacquer system was reviewed. The enzymic formation of the urushiol‐quinone (3) from urushiol was studied by laccase‐catalyzed reactions with pyrocatechols. On the basis of the separated urushiol dimers in both the lacquer and model reaction systems, a nonenzymatic CC and CO coupling reaction of the urushiol‐quinone with the unsaturated chain or with the nucleus of urushiol is discussed as significant reaction path in the polymerization of Japanes lacquer. The films of the lacquer made by a mild oxidation process, a technique applied for so long time in practice, retained their dynamechanical properties completely over

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790105

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractTwo polymers built up of 1,3,4‐oxadiazole‐2,5‐diyl and vinylene resp. ethynylene groups (polymers2and3) were prepared by polycondensation of fumaramide resp. acetylenedicarboxamide with hydrazine sulfate in polyphosphoric acid.2and3exhibit the properties of conjugated polymers—dark colour, semiconductivity, and paramagnetism. The electric conductivity measurments were performed on pellets and on thin films in sandwich and surface cells. The comparison of the semiconducting properties of the polymers mutually and with poly‐p‐xylylidene leads to the conclusion that thetrans‐double bond is a better building unit for conjugated semiconductive polymers than the triple bond and the 1,3,4‐oxadiazole‐2,5‐diyl residue is better than the

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790106

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe products of the reaction of 2‐cyano‐2‐propyl radicals with 1,4‐benzoquinone in toluene solution have been investigated by1H NMR spectroscopy and mass spectroscopy. In agreement with the findings of Bickel and Waters the main reaction products are the hydroquinone monoether1and the hydroquinone diether2. In addition two ringsubstituted products,5and6, have been obtained. The structures3and4, which have been proposed for the main products by Yassin and Rizk, are shown to be i

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790107

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractRadical polymerizations in an alcohol, initiated by hydrogen peroxide were found to afford polymers with hydroxyl end groups. The constants of chain transfer to the initiator and to the alcohol were determined for the polymerization of vinyl acetate, isoprene, and butadiene. The results show the influence of the initiator and the nature of the alcohol in the polymerization mechanism.

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790108

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractFumaronitrile can polymerize quantitatively under mild conditions with anionic initiators. With the initiator butyllithium the kinetics is examined with the help of the1H NMR method. The mechanism of the polymerisation is described which is different in polar and unpolar solvents. In THF an electrontransfer mechanism is responsible for a molecularly uniform oligomer of structure5which does not contain the initiator. In benzene or hexane normal anionic addition of the initiator to the CN‐group of the monomer leads to oligomer

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790109

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe oligomer of fumaronitrile3, obtained by anionic polymerisation of fumaronitrile with butyllithium, is able to isomerise fumaronitrile to maleonitril. Kinetics and thermodynamics are examined and a model for the mechanism is proposed.

ISSN:0025-116X    

DOI:10.1002/macp.1978.021790110

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY