摘要:

A number of formulations were developed using urethane diacrylate oligomer in combination with a series of monofunctional and multifunctional reactive diluents possessing diverse glass transition temperatures from −50°C to 250°C. Films prepared with these formulations were cured under ultraviolet (UV) radiation; their properties, such as hardness, gel content, tensile characteristics, etc., were determined and compared with those of the films cured by electron beam (EB) radiation. Effect of comonomer diluents was investigated in these cases. A good correlation was observed between these properties and the glass transition temperature (Tg) of the copolymer (cured film), prepared under radiation with urethane acrylate, monomer, and comonomer.

ISSN:0360-2559    

DOI:10.1080/03602559508012179

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The morphologies formed in poly[β-(N-carbazolyl)ethylacrylate-co-β-(metacryloyloxy) ethyl-3,5-dinitrobenzoate] [poiy(HECA-co-DNBM)] and in its triblock copolymer with poly(N-acetyliminoethylene) (pMeOZO) were investigated using transmission electron microscopy and differential scanning calorimetry (DSC) techniques. It was found that a lamellar structure was induced in the block copolymer even at a low content (⩽5%) of poly(N-acetyliminoethylene) as a consequence of the specific, dense, layered texture of the poly(HECA-co-DNBM) blocks, having an electron donor-acceptor complex character. The incorporation of poly(N-acetyliminoethylene) resulted in film quality improvement. The addition of small amounts of the block copolymer to the incompatible mixture of poly(HECA-co-DNBM) and pMeOZO having an appropriate composition leads to homogeneous blends able to form continuous films.

ISSN:0360-2559    

DOI:10.1080/03602559508012180

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effect of carbon black particle size and structure on the equilibrium volume swelling and elastic recovery of polychloroprene rubber immersed in hydraulic oil and subjected to uniaxial compression stress was investigated in this study.

ISSN:0360-2559    

DOI:10.1080/03602559508012181

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

With recent development of the petrochemical industry, plastic products have made our society more convenient. However, the disposal of these convenience products has become a serious threat to the environment. Therefore, research on recycling plastic wastes is necessary now more than ever. This paper is a basic study of recycling technology for ABS (acryionitile-butadienestyrene) resin. We tried to show the changes in its mechanical, thermal, rheological, and optical properties during the recycling process.

ISSN:0360-2559    

DOI:10.1080/03602559508012182

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The first part of this article reviews the strong acid/strong base type charged mosaic composite membrane. A template pattern with alternating poly(4-vinylpvridine) (P4VP)/poly(vinyl alcohol) (PVA) lamellae was fabricated upon a microporous membrane by casting of poly[4-vinylpyridine (4VP)-g-vinyl alcohol (VA)] graft copolymer from a water/l-propanol mixture. After a treatment involving the binding of the microporous membrane with the graft copolymer and also domain fixing of the PVA phases, a dilute solution of poly[sodiump-styrenesulfonate (SSS)-g-VA] graft co-polymer/P4VP binary blend was cast on this template surface. After chemical treatments (introduction of a positive charge and domain fixing of ion-exchange regions), we examined the transport of KCl and selective transport of a KCl-sucrose mixture through the charged mosaic composite membrane. The second section reviews the weak acid strong base type charged mosaic composite membrane. In this type, the charged mosaic regions were composed of poly(acrylic acid) (PAA) and quaternized P4VP microdomains. The microstructure of binary blend was observed from scanning electron microscopy (SEM) by wet-etching of films after domain fixing of one component of the binary blend. We examined the transport of KCl and L-phenylalanine through the charged mosaic composite membranes.

ISSN:0360-2559    

DOI:10.1080/03602559508012183

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In the ionic xanthate method of grafting, the increase of sodium hydroxide concentration and liquor ratio increased the grafting parameters up to a limit. The limit varied from one monomer to another. The positive values of the standard degree of concentration of sodium hydroxide indicate that the graft polymerization reaction has happened. The extent of decrease in the grafting parameters with the increase of the liquor ratio may be due to an increase of termination reactions as a result of the increasing number of HOH molecules, with resulting chain transfer reactions to solvent. Grafting parameters also increased with an increase of the concentration of monomers up to a limit. The reactivity of these monomers is in the order: methyl methacrylate > ethyl acrylate > allyl chloride > acrylonitrile > methyl acrylate > allyl alcohol, being dependent on both the radical stabilization and the strength of the electron acceptance of the monomers. The activation energy of the overall polymerization reaction (i.e., grafting and homopolymer) decreased with the increase of the crude grafting yield, and the reverse relation was achieved with the true grafting yield (i.e., grafting reaction only). This difference may contribute to the difference in the conformation of the polymer chains in graft polymerization on the active sites of the cellulose chains.

ISSN:0360-2559    

DOI:10.1080/03602559508012184

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

An analytical method for flow calculations in an annular porous media bounded by a solid outer wall and subject to a countercurrent flow in its inner boundary is presented. The analysis is rigorous and makes it possible to evaluate the effect of the boundaries in the transport capacity of porous channels. The mathematical model is applicable to wicks, such as those found in heat pipes. The paper explores the conditions, that is. the value of critical parameters, under which boundary effects are not negligible and should be taken into account in wick design.

ISSN:0360-2559    

DOI:10.1080/03602559508012185

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This paper deals with both the axial and the tangential annular flows of power-law fluids in concentric annuli, and it specifically focuses on the relation volumetric flow rateQagainst pressure dropP. Initially the mutual compatibility of the hitherto obtained results is analyzed, and from this, new results concerning behavior of a parameter λ [a location of maximum axial (tangential) velocity component] are derived. Then, approximative expressions for relationsQagainstP(independent of A.) are proposed in a sufficiently large region (K,n) where K represents annular aspect ratio andnthe flow behavior indexn. The deviations of these simple relations from the exact ones are negligible.

ISSN:0360-2559    

DOI:10.1080/03602559508012186

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Thin films play an important role in electron microscopy as they can be used to improve the contrast and stability of specimens, as well as to make specimens electrically conductive. In order to avoid overlapping of specimen and coating structures, it is necessary to understand how thin films are formed in the various coating technologies and how to create them reproducibly as part of the different preparation techniques for electron microscopy. In contrast, electron microscopy can be applied to learn more about the structural details of thin films used, for instance, in the optical coating industry. Heat shock fracturing and Pt-C surface replication of the cross sections resulted in reliable transmission electron micrographs (TEM) of the coating microstructure. These studies demonstrate that, under optimal conditions, it is possible to find a correlation between the measured optical properties and the microstructure of the coatings. TEM replica investigations reveal single events, so they can be useful if discrepancies in the (statistical) physical data have to be investigated.

ISSN:0360-2559    

DOI:10.1080/03602559508012187

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The process of gas dispersion in the mixing zone of an extruder employing on-line injection into a viscous polymeric melt, has been analyzed. In the model system considered, the gaseous component was injected into a non-Newtonian melt (LLDPE) via a permeable wall, during which a shear field was imposed at right angles to the direction of flow of the melt. The dispersion of the injectant has been quantified in terms of the spatial coordinate positions of the microvoids as they travel through the melt. Computer simulation was performed to ascertain the trajectories, radial velocities, and times of traverse of the particles migrating from the injection orifice under the imposed shear field. Numerical solutions have been obtained for system angular velocity from 6 to 10 rad/s, melt viscosity from 6 to 6.5 kPa.s, particle diameter/ annular gap ratio of 0.20, injectant/melt density ratio of 0.032, and power law index of 0.51. The computed trajectories were found to be consistent with previously recorded visual observations. The analytical results on the time of traverse (∼0.5–1.0 s) indicated that dispersion by on-line shear injection was viable. The latter results, however, need experimental verification.

ISSN:0360-2559    

DOI:10.1080/03602559508012188

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor