摘要:

AbstractInitial experiments using “Quantimet” image analysing computers linked directly with an electron microscope for the automated assessment of particle size and distribution in the sub‐micron range are described. The ability to analyse polymer dispersions quickly and without the need for photographic procedures has been demonstrated. It has also been shown that statistical parameters of these dispersions can now be determined with a reasonable degree of certainty and with considerably less experimental difficulty Results obtained by this method have been compared with data obtained using micrographs assessed either manually or using the Zeiss‐Endter instrument. Present limitations and future possibilities are in

ISSN:0007-1641    

DOI:10.1002/pi.4980030601

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractBisphenol A polycarbonate was fractionated from methylene chloride solution by a progressive precipitation technique. The intrinsic viscosities of these fractions were obtained in methylene chloride solution and corresponded to a viscosity average molecular weight range of 2 × 103to 80 × 103. The fractions were used to calibrate a gel permeation chromatograph, an experimental Q‐factor of 23.8 was found. The calibration was further confirmed by membrane osmometry and light scattering experiments. The experimental viscosity data demonstrated that the Kurata‐Stockmayer‐Roig relationship is suited to interpret the molecular expansion of polycarbonate in methylene c

ISSN:0007-1641    

DOI:10.1002/pi.4980030602

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe infrared spectrum of polymethyl acrylate has been studied in the region 4000 to 150 cm−1and a detailed assignment mad

ISSN:0007-1641    

DOI:10.1002/pi.4980030603

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractLong‐term dark ageing in the temperature range 35 to 91°C, has shown that hydrogen chloride is released in small but measurable quantities from the surface of fully‐stabilized PVC wire‐insulating compounds. The rate of release is temperature‐ and time‐dependent. For the particular formulations studied, there is an inverse dependence on the half‐power of neutralizer content. Risks to electrical circuit components associated with PVC insulation in enclosed equipment are assessed and shown to be negligible for most normal operatin

ISSN:0007-1641    

DOI:10.1002/pi.4980030604

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractEvidence is presented which shows that both free‐radical and monomer species can be subject to mass transfer resistances in an emulsion polymerisation. The possible causes of these resistances are analysed. In most cases, simple diffusional resistances will not affect the course of an emulsion polymerisation appreciably. However, interfacial resistance to mass transfer which occurs at the water‐particle boundary can have noticeable effects on the polymerisation.The practical consequences of these phenomena are discussed. These can be of particular importance in emulsion copolymerisat

ISSN:0007-1641    

DOI:10.1002/pi.4980030605

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe use of reflectance techniques for the study of surface coatings is discussed and the applications of goniophotometry briefly reviewed. The necessary modifications to enable the Brice‐Phoenix light scattering photometer to be used as a high sensitivity goniophotometer are described together with details of the application of the instrument to the study of point films. Results obtained with different types of coatings are presented in order to show typical effects of variation in, for example: pigmentation, application technique and environmental deterioration. The results are discussed in terms of the subjectively assessed “gloss” of the different coatings and the ways in which the features of the goniophotometric curves may be most effectively and compactly described.Goniophotometry is suggested as a potentially valuable and sensitive technique for the quantitative study of the early stages of deterioration of polymer

ISSN:0007-1641    

DOI:10.1002/pi.4980030606

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe dyeing methods of anionic dyes on nylon, cationic dyes on polyacrylonitrile fibres, and non‐ionic (disperse) dyes on nylon, cellulose acetate, polyethylene terephthalate, and polypropylene are surveyed and their chemical mechanism outlined.The mass coloration of plastics, and the state of disperse dyes in the fibre are also briefly discussed. Dyeing of the polar hydrophobic fibres with disperse dyes differs from all other types of dyeing in that the dye—fibre bonding is overwhelmingly hydrogen bonding, and van der Waals or hydrophobic bonding seems to have a negligible influence. All the polar groups and aromatic nuclei in the dye and the fibre can take part in the bonding, and the fibre can act as proton acceptor or donor. Because of these facts disperse dyeing has special features, including: linearity of adsorption isotherms; direct relation between water solubility and fibre solubility of dye and between number of hydrogen‐bonding groups in a dye and its solubility in the fibre; constancy of dye diffusion coefficient in the fibre, and additivity of solubility in the fibre of certain disperse dyes; and the possibility of dry dyeing, either from the vapour phase or from non‐aqueous solvents.The size, shape, and number and nature of polar substituent groups of the disperse dye molecule influence its diffusion coefficient in the fibre.Polypropylene fibre, if unmodified, has no polar or ionic groups and has no affinity for most disperse dyes; a very few however, have sufficient attraction by dispersion forces, to enable them to give weak shades on thi

ISSN:0007-1641    

DOI:10.1002/pi.4980030607

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractA review of four papers presented at a Symposium organised by the Plastics and Polymer Group of the Society of Chemical Industry on October 27, 1970. Two described the operation of established systems while a third dealt with lessons learned from them. The fourth dealt with a system not yet operational and prospects for the future.

ISSN:0007-1641    

DOI:10.1002/pi.4980030608

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980030610

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY