摘要:

AbstractThe polymerization of methyl methacrylate(MMA) initiated with starch dissolved in water was carried out in the presence of Cu(II) ion. It was concluded that the polymerization proceeded in the water phase, particularly in the hydrophobic areas (or micelles) formed by the starch. The initiation mechanism was discussed. The formation of a complex of Cu(II) ion with starch and water was confirmed by the measurements of electric conductance and difference spectrum of the starch solution in the presence of CuCl2.

ISSN:0360-8905    

DOI:10.1002/polc.5070680103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe techniques of heterogenization of homogeneous catalysts (molybdenum halogenized) for acetylene monomers polymerization on polymer supports have been worked out. The latter were carbon‐chain polymers grafted with functional groups. The properties of homogeneous and heterogenized catalytic systems have been compared. Heterogenized catalysts induce formation of the greatest amount of high‐molecular polyphenylacetylene. Some assumptions (on basis of MMD polymer analysis) about the mechanism of acetylene monomers polymerization by use of such catalysts have been sugges

ISSN:0360-8905    

DOI:10.1002/polc.5070680104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractTo obtain polymer supports with different functional coverage, the kinetic peculiarities of radiation‐induced gas‐phase grafting of allyl (allyl alcohol, ally and diallyl amines) and vinyl (acryl and methacryl acids, their methyl ethers, methylvinylketone, 2‐ and 4‐vinylpyridine, acrylonitrile) monomers to polymer powder (polyethylene, polypropylene, polystyrene, and copolymer of ethylene with propylene) were studied. The degrees and radiation yields of grafting were measured and evidence of the grafting occurrence is given. The radiation yield of allyl monomers grafting to polyethylene was found to be 10–20 molecules/10 eV of absorbed energy and was found to keep constant on a change of the dose rate from 3 × 10−3to 6.5 Mrad/min. That testifies to the absence of second‐order chain termination and provides wide possibilities for effective use of various radiation sources. By grafting some monomers containing radioactive isotopes (14C,3H) and analyzing the grafted product after extraction, the ungrafted homopolymer content was shown to be less than 10%. The appearance of some additional absorption bands from fragments of the grafted monomers in the IR spectrum of the treated polymer was considered as evidence of grafting. Some polymer‐analogous reactions of the grafted polymer (reduction, saponification, hydrolysis, formation of Schiff bases) are given as illustrations of the validity of the method proposed for producing polyfunctional coverage of the macromolecular carries for active

ISSN:0360-8905    

DOI:10.1002/polc.5070680105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractIsoprene and butadiene polymerization has been studied in the presence of homogeneous and heterogenized, polymer‐supported, “cobalt” catalytic systems. Donor‐acceptor or covalent heterogenization Co(II) compounds resulted in retardation of initiation and deactivation reactions in catalytic systems, in increasing molecular masses, and in an integral yield of polymers. It was concluded from analysis of growth‐rate constants, as well as from the structures of the polymers formed, that the active sites were the same in both types of catalysts. The heterogenized systems were postulated to inhibit yielding cobalt compounds in a redu

ISSN:0360-8905    

DOI:10.1002/polc.5070680106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractStructural changes are detected by x‐ray diffractometry when a semicrystalline polyester of molecular weight of about 1000 having free carboxyl and hydroxyl end groups is reacted with MgO. The ratio of MgO to the COOH end groups alters the diffractograms. Supplementary structural studies were performed by various electron microscopic techniques. Differences were also detected in the supermolecular structure as a function of the MgO to COOH ratio. Furthermore, at the equivalent ratio a fiber‐forming solution can be prepared; while the equimolar ratio results in a gel‐like system. This is in accordance with our previous conclusions about the mechanism of the reaction (association), i.e., at a molar ratio of the COOH group to MgO of 2:1 (equivalent amounts) the forming of aCOO−Mg2+−OOClinkage is preferred; while in the case of an equimolecular amount of COOH and MgO, the possibility of the association of other groups of the polyester chain (such as CO groups and alcoholic end groups) increases creating associates

ISSN:0360-8905    

DOI:10.1002/polc.5070680107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA new support for whole‐cell immobilization based on crosslinked pectate with iminodiacetate as polydentate spacer and iron is proposed. Microorganisms of the strainsEscherichia coli, Staphiloccoccus aureus, Saccharomyces cereviseae, andCandida tropicalishave been immobilized on this matrix. Immobilization capacity of the support, conditions of adsorption, and differences in respiration between free and fixed cells have been evaluated. Using scanning electron microcopy, electron micrographs of the support and of cells fixed on the support were prepared in order to examine fixation in detail. It was found that it is possible to immobilize an important active biomass, with a very strong binding strength, between cells and support, without the inherent diffusional limitations encountered in other methods. Respiration measurements showed increased oxygen demand by immobilized cell

ISSN:0360-8905    

DOI:10.1002/polc.5070680108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe hydrolysis of α‐N‐Benzoyl‐L‐arginine ethyl ester (BAEE) as a substrate under monolayers of papain and trypsin at the air–water interface was studied using an automated Lauda film balance to characterize the monolayers and a small resin‐flask reactor with movable barriers for surface‐layer compression. The rates of reaction were followed by UV spectrophotometry. The hydrolysis rate increased with moderate increases in surface pressure a

ISSN:0360-8905    

DOI:10.1002/polc.5070680109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA method for grafting enzymes on polysaccharides using a redox system as a radical initiator is reported (Fe2+‐H2O2). Glycidylmethacrylate was used as a vinylating reagent and the reaction product with enzymes (HRP, GOD, Am, ChT) was copolymerized with different matrices (cellulose, Sepharose, Sephadex, starch). During the enzyme vinylation reaction, no appreciable denaturation was observed, and various products were obtained using chromatography. Various factors affect the final activity of the copolymers; these include the redox system, the type of support, and the quantity and type of vinyl monomer added. Using a fixed quantity of enzyme, recovery of activity varied 2–50%. Graft copolymers thus obtained appear to be stable in storage and present higher thermal stability than that of the free enzyme. The kinetics of these copolymers indicate that diffusion is not appreciably limited, and that the immobilization reaction does not alter the enzymatic activ

ISSN:0360-8905    

DOI:10.1002/polc.5070680110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractMacroporous polymethacrylates containing imidazole groups as well as hydrophobic side chains adsorb methemoglobin (metHb). The protein‐matrix interaction was investigated by means of an electron paramagnetic resonance (EPR) spectroscopy. The adsorption of metHb to the imidazole containing matrices occurs by complex formation with the iron of the prosthetic group. In case of steric hindrance or long spacers, this complex formation is not primarily responsible for the adsorption. The binding of metHb to hydrophobic side chains clearly demonstrates the presence of a metHb‐H2O‐metHb‐OH mixture. Moreover, the protein‐matrix interaction induces conformational changes in the protein component. In this case, additional signals in the EPR spectra indicate the formation of a cytochrome P450‐lik

ISSN:0360-8905    

DOI:10.1002/polc.5070680111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe hydroxyethyl‐methacrylate Spheron‐gel activated by cyanogen bromide was used for the binding of anti‐immunoglobulin antibody. Anti‐immunoglobulin columns were used for separation of human T and B cells. Depletion of surface immunoglobulin‐positive B lymphocytes from human peripheral blood or tonsils by filtration through anti‐immunoglobulin‐Spheron column was very effective; the purity of obtained T cells being more than 90%, i.e., slightly higher than those of the nylon‐wool‐column pur

ISSN:0360-8905    

DOI:10.1002/polc.5070680112

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY