摘要:

AbstractThe radiation induced, graft copolymerization ofm‐ andp‐fluorostyrene onto nylon was successfully achieved. Grafting was followed by nitration of the fluorostyrene groups in the copolymer to provide substrates which were active to the coupling of various enzymes and proteins. Bovine serum albumin, ovalbumin, pepsin, β‐galactosidase, and alkaline phosphatase proteins all coupled very efficiently but the activities of the coupled enzymes were relative

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820301

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractThe kinetics of the polymerization of tetrahydrofuran by acetyl perchlorate in methylene chloride solution was studied, and the results were compared with those previously reported by using perchloric acid/acetic anhydride as catalyst. The initiation and propagation mechanisms are discussed by taking into account the influence of the counterion. The initiation reaction takes place instantaneously, but the propagation proceeds by macroesters and macroions and the contribution of macroester to propagation is much lower than the contribution of macroions.

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820302

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractThe kinetics and mechanism of the polymerization of tetrahydrofuran with terephthaloyl perchlorate in methylene chloride or cyclohexane were analyzed. This polymerization produces dicationically active polymers and takes place without induction period. Propagation in both solvents proceeds as a reaction being first order in monomer, and it changes with the polarity of the solvent because ionic and covalent species take part with different growing rates. The macroester mole fractions in cyclohexane and methylene chloride are 0,99 and 0,86, respectively.

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820303

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractIn order to study the effect of adjacent functional groups on electron‐donor acceptor (EDA) complex formation, the following donor or acceptor compounds were synthesized: diethyl 2‐(2,4‐dinitrobenzyl)malonate (13), diethyl 2,2‐bis(2,4‐dinitrobenzyl)malonate (14), diethyl 2‐(3,5‐dinitrobenzyl)malonate (5), diethyl 2,2‐bis(3,5‐dinitrobenzyl)malonate (6), diethyl 2‐(4‐dimethylaminobenzyl)malonate (10), diethyl 2,2‐bis(4‐dimethylaminobenzyl)malonate (11). The acceptor compounds5, 6, 13, and14were complexed withN,N‐dimethyl‐4‐dimethylaminoaniline (1) as donor, and the donor compounds10and11, with 1,3,5‐trinitrobenzene (2) as acceptor. The wave length of the absorption maximum (λmax), the association constant (KCT), the enthalpy (δH), and entropy (δS) of these EDA complexes were determined. It was found that λmaxof complexes6–1and11–2show a bathochromic shift compared with complexes5–1and10–2, and the values ofKCT, −δH, and −δSare higher. The value of λmaxfor complex14–1is not different from that of complex13–1, and the values ofKCT, −δH, and −δSare lower. It was concluded that the stability of the EDA complexes of the 2,2‐dibenzylmalonate derivatives6, 11, and14, is influenced

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820304

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractDinitrogen complexes of poly{1‐[4‐(chlorodicyclopentadienyltitanio)phenyl]ethylene‐co‐1‐(4‐bromophenyl)ethylene‐co‐1‐phenylethylene} (2a – e) were synthesized. It was found that there is an equilibrium between the mononuclear and binuclear complex. Ammonia was formed after hydrolysis of the reaction mixtures resulting from2a – eand lithium naphthalide in a nitrogen atmosphere. The yield of ammonia increased extremely with decreasing content of titanocene in the polymer. In the system with2a41,7 mol ammonia were formed

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820305

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractPolyamides3containing constant and definite numbers of oxyethylene units were prepared by condensation polymerization of suitable diamines and diesters, both of which containing oxyethylene units. The polymer structure was determined by IR and1H NMR spectroscopy. Almost all polymers are crystals melting at ≈ 40°C and show a complexation ability towards alkalimetal cations. It was also found that diesters containing oxyethylene units show a higher condensation rate than alkylene diesters, which is explained by an inductive effect of the ether oxygene. However, no remarkable difference in the condensation rate was found between diamines containing oxyethylene units and the corresponding aliphatic diamin

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820306

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractSome asymmetric and polyfunctional stationary phases were prepared by attachment of the ε‐amino group of L‐lysine copper complex to crosslinked polystyrene or agarose, substituted or not by hydrophilic spacer arms. After copper elimination, the sorbents exhibit three functions, one of a carboxylic acid and one of an α‐primary amine, and moreover one of a secondary amine located at a variable distance far from the asymmetric carbon, but near the backbone of polymer. These sorbents were tested in the chromatographic extraction of cephalosporin C (1) from an aqueous mixture containing several α‐amino acids. They exhibit an affinity higher for the antibiotic than for the amino acids and even for the dicarboxylic a

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820307

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractSeveral telomers of acrylic acid with carbone tetrachloride were prepared. Their average degree of polymerization, which was between 10 and 50, was determined by several analytical methods (elemental analysis, viscosimetry, and GPC). From the kinetic equations of telomerization a relation betweenDPnof these telomers and the experimental conditions is established. Fixation of hydroxylic compounds through direct esterification was studied and it was found that the prepared telomers can be used as hydrosoluble carriers for drugs containing primary alcohol or phenol functions.

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820308

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractThe modification of polystyrenes (1 – 8% cross‐linked) by imidazole ligands, via chloromethylation, is described. The resulting resins, having 10–40% of the phenyl groups substituted by a CH2(N)‐imidazolyl group, have been treated with first‐row transition metal salts under varying conditions. Upon reaction of the modified polymer with the transition metal salts in CHCl3, a shrinking of the polymer is observed which is explained by additional cross‐linking by the metal ions. The final products have the general formula Mt(PS‐Iz)m(NnBuIz)nX2, in which PS‐Iz stands for a polystyrene‐bound imidazole ligand, NnBuIz forN‐butylimidazole (a ligand used to solubilize the metal salts in CHCl3) and X for the anion (perchlorate, nitrate, tetrafluoroborate, chloride, bromide). Metal ions used are Co(II), Ni(II), Cu(II), and Zn(II); values of 2–6 have been found formin most cases. The value ofnusually is very small (0,2–1,0) in most cases. Spectroscopically the polymeric coordination compounds behave like the corresponding monomeric coordination compounds, Mt(N‐benzylimidazole)mX2, indicating that the imidazole ligands in the polymer are quite flexible in their coordination behaviour, except in case of very low degrees of substitution or

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820309

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY

摘要:

AbstractA series of copolymers ofN‐(2‐hydroxypropyl)methacrylamide were prepared, which contained side chains of the general formula ‐Gly‐X‐Y‐NAp, where Gly ¨ glycine; X ¨ glycine, alanine, β‐alanine, valine, leucine, isoleucine, phenylalanine; Y ¨ phenylalanine or tyrosine; NAp ¨p‐nitroanilide, the latter modelling biologically active compounds. The rates of chymotrypsin‐catalyzed hydrolysis ofp‐nitroanilide groups at pH = 8,0 and 25°C were determined over a range of substrate concentrations to derive values forkcatandKM. The results allowed us to determine the influence of the structure of side chains on the rate of cleavage of Y‐NAp. The increase in the susceptibility to chymotrypsin attack with an increasing spacing of the Y‐NAp residue from the backbone of the polymer chains is demonstrated by comparing the kinetic data of copolymers containing ‐Gly‐Gly‐Phe‐Phe‐NAp, ‐Gly‐Gly‐Phe‐NAp and ‐Gly‐Phe‐NAp side chains. Results obtained with α‐chymotrypsin were compared with the cleavage of the above polymer substrates with chymotrypsin covalently

ISSN:0025-116X    

DOI:10.1002/macp.1981.021820310

出版商:Hüthig&Wepf Verlag    

年代:1981

数据来源: WILEY