摘要:

AbstractThe relationship between the activity to initiate graft copolymerization under photo‐irradiation and the photo‐induced radicals of periodic acid‐oxidized cellulose (aldehyde cellulose) was investigated. Aldehyde cellulose proved to have a high activity to initiate graft copolymerization under photo‐irradiation, and the effect was profound, especially for hydrophilic vinyl monomers such as acrylic acid and acrylamide. By studying the ESR spectrum of photo‐irradiated aldehyde cellulose, the formation of a radical giving a singlet spectrum with linewidth of 14–15 G and agvalue of 2.001 was observed. This was assigned to an acyl radical orginating in the aldehyde group of the sample. Employing low molecular weight aldehydes, it was confirmed that an acyl radical formed on aldehyde compounds by photo‐irradiation has a function sufficient to initiate the graft copolymerization of vinyl monomers. It was concluded that the high activity needed to induce the graft copolymerization of aldehyde cellulose under photo‐irradiation was based on an acyl radical which originated in the aldehyde grou

ISSN:0021-8995    

DOI:10.1002/app.1979.070230101

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe kinetic study of the radical polymerization of phenyl glyceric ether methacrylate, taken as model of the corresponding derivative of bisphenol A, initiated by the system benzoyl peroxide/dimethylp‐toluidinep‐toluene sulfinic acid salt, was performed. The effect of hydroxylic groups of the monomer on the polymerizability was established. The system used as initiator allows rapid polymerization of the monomer in presence of stabiliz

ISSN:0021-8995    

DOI:10.1002/app.1979.070230102

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

年代:1979

数据来源: WILEY

摘要:

AbstractThis work describes the determination of oil either as such or in oil‐utilizing resins such as alkyds and urethanes, by means of NMR techniques. Both the qualitative and quantitative analyses are demonstrated and the accuracy is assessed. Typically, the complete analysis of an alkyd resin takes less than 1 h

ISSN:0021-8995    

DOI:10.1002/app.1979.070230103

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

年代:1979

数据来源: WILEY

摘要:

AbstractBased on experimental data, changes of properties of plasticized PVC containing stearates of Ca, Zn, Cd, and Pb stabilizers during thermal degradation are discussed. The mechanism of action of these stabilizers is described in kinetic form.

ISSN:0021-8995    

DOI:10.1002/app.1979.070230104

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

年代:1979

数据来源: WILEY

摘要:

AbstractGeneral correlations were developed to estimte polymer thermal conductivities for four cases—amorphous polymers above the glass temperature; amorphous polymers below the glass temperature; semicrystalline polymers above the melting temperature, and semicrystalline polymers below the melting temperature. The correlations based on readily available parameters (mer weights, densities at 25°C, specific heats) yielded calculated thermal conductivities that deviated by only 1%–2% from experimental va

ISSN:0021-8995    

DOI:10.1002/app.1979.070230105

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe high‐strength, high‐modulus Kevlar 49 fiber is widely used today because of its superior properties. In this paper, we discuss the fundamental physicochemical nature of the commercial fiber. It is an extended chain polymer, poly(p‐phenylene terephthalamide), which is highly crystalline. Extensive analysis shows that the material composition is quite consistent from lot to lot and is low in impurities. The fiber absorbs water reversibly; the extent of absorption is related to the ash content. The well‐known interaction of the fiber with ultraviolet light is illustrated with spectra, and the thermal stability of the fiber is demonstrated with various thermal analysis tec

ISSN:0021-8995    

DOI:10.1002/app.1979.070230106

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

年代:1979

数据来源: WILEY

摘要:

AbstractCoated optical fibers (∼100 μm) were prepared exhibiting fracture strengths in excess of 750 ksi (5.3 GN/m2) for lengths up to 100 meters. To achieve this we have developed a novel coating and coating application process. The coating is an epoxy acrylate, cured by UV irradiation, which may contain a multifunctional silane coupling agent. The coating liquid was applied to the fiber prior to solidification by an applicator, which facilitates centering of the fiber in the coating. Our coating system offers advantages in that there is no solvent to remove, thereby avoiding possible surface “corrosion” of the glass fiber. The reasonably low viscosity of the coating formulation allows for the extensive wetting of the fiber surface irregularities prior to solidifi

ISSN:0021-8995    

DOI:10.1002/app.1979.070230107

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

年代:1979

数据来源: WILEY

摘要:

AbstractMelt blends of polycarbonate and poly(ethylene terephthalate) were prepared and examined for their transitional behavior by thermal analysis and dynamic mechanical testing. A singleTgwas observed for compositions containing more than 60%–70% PET by weight while compositions below this range showed two glass transitions. From this it is concluded that PC and PET are completely miscible in the amorphous phase for PET‐rich compositions, whereas PC‐rich blends separate into two amorphous phases which apparently contain both components. Melting point and crystallization behavior are conssistent with these conclusions and suggest that very little if any interchange reactions occur between the ester and carbonate groups during melt m

ISSN:0021-8995    

DOI:10.1002/app.1979.070230108

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

年代:1979

数据来源: WILEY

摘要:

AbstractAdherent films of copolymers on different metal surfaces were formed by an electrolytically initiated polymerization of acrylonitrile (AN) and acrylic acid (AA) in 0.05NH2SO4aqueous solution. The electrolysis was carried out under a constant current. Hydrogen overvoltages for five different metals used as the cathode were measured in order to interpret the nature and quality of the coating. Solutions containing varying volume fractions of AN and containing different electrolytes gave rise to coatings of varying film thickness. Based on the analyses of copolymer compositions, it is believed that the polymer was formed at the cathode by a free‐radical propagation mechanism. The film hardness and the adhesion between the polymer and the metal surface were measured with an Arco microknife. Furthermore, the scanning electron microscope (SEM) was used to examine the structure of the film surface and cross section. The corrosion rates of the coated and uncoated metals in substitute ocean water were also measured for purposes of evaluation of the coating

ISSN:0021-8995    

DOI:10.1002/app.1979.070230109

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

年代:1979

数据来源: WILEY

摘要:

AbstractA low molecular weight copolymer of vinylbenzyl chloride and butadiene was quaternized with N‐dimethylaminoethylmethacrylamide. The resin was coated from water solution to give a photorelief plate which could be developed with water. A photocured protective coating on steel showed good toughnes

ISSN:0021-8995    

DOI:10.1002/app.1979.070230110

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

年代:1979

数据来源: WILEY