摘要:

AbstractThe preparation and characterization of 2‐aminoethyl 2‐(p‐methacryloyloxybenzoyloxy)ethyl hydrogen phosphate (7) are described. This monomer was polymerized with 2,2′‐azoisobutyronitrile (AIBN) and the properties of the resultant polymer are

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791001

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe catalytic hydrolysis ofp‐nitrophenyl acetate (PNPA) by 4(5)‐imidazolylmethylated poly(vinyl alcohol) (IMPVA) was studied. When IMPVA (\documentclass{article}\pagestyle{empty}\begin{document}$ \overline {{\rm DP}} \approx 2000 $\end{document}, imidazolyl content: 2,7 mole‐%) was used as catalyst, the rate of catalytic hydrolysis showed substrate saturation phenomena and could be described by a Michaelis‐Menten kinetics withKm= 3,3 mmol·l−1andkcat= 9,4·10−3min−1.Kmandkcatincreased with increasing imidazolyl content in the IMPVA (imidazolyl content = 13,0 mole‐%,Km= 53 mmol·l−1andkcat= 8,7·10−2min−1). Addition of ethanol to the reaction mixture resulted in a decrease inKmandkcat(ethanol conc. = 50 vol.‐%,Km= 1,5 mmol·l−1andkcat= 1,7·10−3min−1). In the presence of boric acid,Kmincreased, whilekcatvaried in a complicated manner. The catalytic properties of IMPVA were found to be also affected by the degree of polymerization, and when an IMPVA of\documentclass{article}\pagestyle{empty}\begin{document}$ \overline {{\rm DP}} \approx 500 $\end{document}with an imidazolyl content of 2,7 mole‐% was used as catalyst, substrate s

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791002

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractPolyacrolein (1) was transformed into poly(allyl alcohol) (2), poly[1,1‐bis(hydroxymethyl)ethylene] (5) andN‐substituted poly(vinylmethanimine)s8, 9a–cand10. By subsequent reactions on these polymers reactive carriers with isothiocyanato‐, diazo‐, and azido groups were formed or by reaction with BrCN activated carriers were obtained which are able to bind enzymes covalently. The binding abilities of some reactive carriers were investigated for papain and trypsin. The effect of the pH‐value during the coupling reaction, the amount of offered enzyme, the content of the reactive groups per g carrier and the effect of different reactive groups on the binding ability of the carriers were investigated. For immobilized papain and trypsin the enzymatic activity, the pH‐optimum of their activity, and the apparent Michaelis constantKM(app)were determined. The dependence of the activity on the temperature was also

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791003

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractA detailed study was carried out on the new synthesis of poly[oxycarbonyloxy‐(1,4‐cyclohexylene)oxycarbonyloxymethylen‐1,4‐phenylenemethylen] (3) from 4‐bromomethylbenzyl bromide (1), dipotassium 1,4‐cyclohexanediolate (2) and carbon dioxide by using a variety of crown ethers as catalysts, which has recently been found by the present authors. Crown ethers having an 18‐member‐ring showed the best catalytic property of the various crown ethers, and the reaction was conducted in various solvents at 40–120°C by using 1,4,7,10,13,16‐hexaoxacyclooctadecane (18‐crown‐6 ether). A maximum yield with the highest molecular weight was obtained from the reaction at 100°C in dioxane solvent. In addition, as result of a kinetic study a plausible mechanism could be proposed. Similar reactions were also carried out with dipotassium and disodium 1,4‐phenylenedimethanolate (6a, b) and dipotassium 4,4′‐isopropylid

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791004

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractCationic polymerization of oxepane (hexamethylene oxide) (1) in CH2Cl2and C6H5NO2as solvents was initiated with 1,3‐dioxolan‐2‐ylium hexafluoroantimonate (2). Dissociation constants (KD) of the ion‐pairs of polyoxepane into ions were measured:KD(in CH2Cl2,T= 25°C) = 2,8·10−5mol·l−1[ΔHD= −3,8 kJ·mol−1(−0,9 kcal·mol−1), ΔSD= −98 J·mol−1·K−1(−23,4 cal·mol−1·K−1)];KD(in C6H5NO2,T= 25°C) = 1,6·10−3mol·l−1[ΔHD= −7,1 kJ·mol−1(−1,7 kcal·mol−1), ΔSD= −78 J·mol−1·K−1(−18,7 cal·mol−1·K−1)]; these values are close to those of the ion‐pairs of polytetrahydrofuran. Rate constantskp+andkp±, determined from the kinetic measurements for degrees of dissociation of macroion‐paris ranging from 0,02 to 0,21 (in CH2Cl2) and from 0,09 to 0,7 (in C6H5NO2), were found to be identical within an experimental error of kinetic measurements. The activation parameters of propagation were measured

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791005

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractCircular dichroism (CD) and ultraviolet absorption (UV) spectra were measured for poly{γ‐[2‐(9‐carbazolyl)ethyl]L‐glutamate} (PCLG), whose side chain chromophore has three π – π*transitions in a wavelength region not overlapping with the n – π*transition of the main chain peptide group. For the dilute solution in any given helicogenic solvent, the observed CD sign had a good correlation to the polarization direction of the π – π*transitions. On the other hand, a concentrated solution with a concentration of ca. 15 wt.‐% was found to form a liquid crystalline phase, which was probably nematic at room temperature. The CD spectral profiles of the cast film of the polypeptide were quite different from that of the dilute solution. Origins of the optical a

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791006

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractViscosities of six kinds of monomers—styrene, methyl methacrylate, butyl methacrylate, butyl acrylate, vinyl acetate, and octyl methacrylate—were measured under high pressures up to 1000 bar at 30°C. The pressure dependences of the viscosities could be well expressed by an exponential function and correlated with the effect of the termination rate constant determined previously. Therefore, the termination constants at various pressures can be predicted by the evaluation of the pressure dependence of the viscosity of the corresponding monomer. The applicability of O'Driscoll's termination theory under high pressure is also discu

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791007

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractCationic polymerizations of anethole in methylene dichloride initiated by triphenylmethyl hexafluoroantimonate were studied by dilatometry and UV‐visible spectroscopy at temperatures between 0 and 35°C. Initiator consumption continued throughout polymerization, reaching 85–95%. Monomer conversion ranged from 75 to 98%. Reaction half‐lives were on the order of 15 to 60 min at 25°C. Polymer molecular weights were bimodal with some evidence of branching and cross‐linking. The principal termination reaction appeared to involve formation of a chromophore absorbing at 501 nm. Rate constants on the order of 10−3dm3·mol−1·s−1for initiation and 1 dm3·mol−1·s−1for propagation

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791008

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractA new type of photoredox polymer with incorporated thionine, (7‐amino‐3H‐phenothiazin‐3‐iminium chloride). (TH) and alkylenepolyamine groups was prepared by the reaction of poly(acrylic acid) with TH and alkylenepolyamines such as ethylenediamine (en), tetraethylenepentamine (3,6,9‐triazaundecane‐I,II‐diamine), (tetraen) and poly(iminoethylene). The photoredox polymers were able to induce photopotential in aqueous solution in the absence of any other redox reagents. The polymers from TH with on and with tetraen induced photopotentials of 180 mV and 167 mV, respectively. The photopotential of the former system was much higher than that of the system, TH/en. The induced photopotential of the polymer systems did not depend so much upon the mole ratio [en]/[TH]of the pendent groups, while the photopotential of the TH/en system was strongly dependent upon [en]/[TH]. Effects of the polymer structure

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791009

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractThe preferential solvation of poly(acrylic acid) and its sodium salt in water/dioxane mixtures was studied. The comparison with results previously obtained on poly(χ‐L‐glutamic acid) indicates the preferential solvation of the latter polymer by dioxane is due to the existence of the peptide group in the polymer. The viscosimetric behavior of poly(acrylic acid) in water/dioxane mixtures is interpreted by the existence of water‐dioxane complexes with a definite stoechi

ISSN:0025-116X    

DOI:10.1002/macp.1978.021791010

出版商:Hüthig&Wepf Verlag    

年代:1978

数据来源: WILEY