摘要:

N-Methyl- and N-n-propyl-N,N-dimethacrylamides (MDMA and PDMA), N,N′-dimethyl-N,N′-dimethacrylhydrazine (DMDMH), N,N′-dimethyl-N,N′dimethacrylethylenediamine (DMDME), and N,N′ -di-methyl-N,N′-dimethacrylurea (DMDMU) were synthesized and polymerized with a radical initiator. All of these monomers were homopolymerized to give soluble head-to-head (h-h) cyclopolymers which were obtained through a h-h cyclopolymerization, i.e., a repeated cycle of intermolecular tail-to-tail (t-t) propagation and intramolecular h-h cyclization. The thermal properties of these h-h cyclopolymers were determined. In order to obtain h-h poly(methacrylic esters), the hydrolysis of these polymers was attempted under various acidic and alkaline conditions. It was confirmed by IR spectra that h-h poly(methacrylic acid) and h-h poly(ethyl methacrylate) were obtained by hydrolysis of poly(PDMA) with concentrated KOH aqueous solution and by alcoholysis of poly(DMDMH) with KOH-ethanol solution, respectively. However, the isolation of these h-h polymers was not successful.

ISSN:0022-233X    

DOI:10.1080/00222338408065900

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The pH dependence of the conformation of poly-(L-lysine) with 4.6 mol% of its side chain amino groups attached to an azo dye, 4′ -dimethyl aminoazobenzene-4-carboxylic acid, has been studied. Circular dichroic spectra showed that in acidic as well as in neutral media the polymer exists in the random coil conformation, like that of poly-(L-lysine). In basic medium the polypeptide acquires a β-structure, unlike poly-(L-lysine) which exists in an α-helical conformation.

ISSN:0022-233X    

DOI:10.1080/00222338408065901

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Polychelates of Cu(II), Ni(II), and Co(II) with 4,4′-phenylylenebis-azodisalicylic acid have been prepared. All the polychelates are dark colored and insoluble in all common organic solvents. Octahedral structures are suggested on the basis of electronic spectral, infrared, magnetic susceptibility, and thermogravimetric analysis. A few ligand field parameters have been determined for the Ni (II) polychelate.

ISSN:0022-233X    

DOI:10.1080/00222338408065902

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The enzyme and nonenzyme hydrolyses of the pendent ester groups in the copolymer of p-nitrophenyl methacrylate and acrylamide [poly(p-NPMA/AAm)] were kinetically investigated. The pendent ester groups in poly(p-NPMA/AAm) were found to be cleaved by esterase and α-chymotripsin but were not cleaved by lipase. The catalytic ability of esterase to hydrolyze the ester groups in the copolymer was very smaller than that in p-nitrophenylacetate (p-NPA), which is a monomeric model. The maximal velocity for the esterase-catalyzed hydrolysis of ester groups in poly(p-NPMA/AAm) increased with an increase in the mole fraction of AAm units in poly-(p-NPMA/AAm), while the Michaelis constant was almost independent of the composition of the copolymer. The pendent ester groups in poly(p-NPMA/AAm) are known to be strongly hydrolyzed by alkaline solution but only slightly hydrolyzed by acidic solution. The alkaline hydrolysis velocity of poly(p-NPMA/AAm) was larger than that of monomeric p-NPA, and it was enhanced by increasing the mole fraction of AAm in poly(p-NPMA/AAm).

ISSN:0022-233X    

DOI:10.1080/00222338408065903

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Immobilization of carboxypeptidase A on periodate oxidized cellulose, as a biocompatible carrier, was investigated. The properties of the enzyme-polymer complex and the release of the enzyme from the polymer were studied. The thermal and chemical stability of the enzyme is enhanced by immobilization, possibly due to stabilization of enzyme conformation.

ISSN:0022-233X    

DOI:10.1080/00222338408065904

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

An expression for the Flory constant ϕ is derived according to which ϕ should depend on the polymer-solvent pair and the temperature. The variations of ϕ, [η], and k, the latter two being fundamental terms in the equation,C/ηSP=1/[η] - kC, are utilized for the determination of the unperturbed dimension of polymer molecules in solution. The importance of k, and the alternative expression which has been derived for k, are discussed.

ISSN:0022-233X    

DOI:10.1080/00222338408065905

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Various newer polyhydrazides of high thermal stability were prepared by the low temperature solution polymerization of amino hydrazides with dicarboxylic acid chlorides. The inherent viscosity of these polymers varied from 0.20 to 0.34. Results of differential thermal analysis and thermogravimetric analysis indicate that decomposition starts above 180° and the steep weight loss of the polymer takes place from 300 to 400°. Melting points of crystalline polymers were determined by differential thermal analysis.

ISSN:0022-233X    

DOI:10.1080/00222338408065906

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Several structural isomers of vinylsalicylic acid and the corresponding methyl vinylsalicylates have been synthesized in this laboratory previously and have been polymerized and copolymerized with methacrylic acid and with methyl methacrylate. The monomer-ic as well as the polymeric compounds have been tested for their antimicrobial and cytotoxic properties. This article also deals with the sunscreening properties of some polymeric salicylic acid derivatives and their possible use as the effective ultraviolet-absorbing agent in skin protection formulations. The results show that making homopolymers and especially copolymers is a way of increasing one property and decreasing another, making new compounds with more specific properties.

ISSN:0022-233X    

DOI:10.1080/00222338408065907

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Polymeric chelates prepared by reacting a solution of poly(8-hydroxyquinoline-7,5-diylethylene) with various metal ions in acetic acid are characterized by elemental analysis, IR and UV reflectance spectral studies, and magnetic susceptibility measurements. These properties are explicable in terms of their expected structures. TGA and electrical conductivity of these polychelates are compared mutually and also with those of the parent polymer sample. The polymeric chelates are found to be less stable than the parent polymer sample.

ISSN:0022-233X    

DOI:10.1080/00222338408065908

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0022-233X    

DOI:10.1080/00222338408065899

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor