摘要:

Polymeric films were prepared under UV radiation with tetraacrylated urethane oligomer in combination withN-vinyl pyrrolidone (NVP) using a set of four photoinitiators (Irg 907, Irg 651, Irg 369, and Irg 184). The study evaluates optimum photoinitiator concentration and radiation dose. Various film properties such as gel content, swelling ratio in acetone, pendulum hardness, tensile strength, and elongation at break were determined. These formulated solutions were coated on wood substrates, and gloss and hardness of the film cured on the wood substrate were determined. Some of these properties are compared with those of the films cured on the glass plates. Irg 369 is found to be the best photoinitiator to produce better films, both on glass plate and on wood substrate.

ISSN:0360-2559    

DOI:10.1080/03602559508009594

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The plasticizing effect of low molecular weight PVC prepared by vibromilling on PVC and its effect on mechanical properties of PVC were studied through Brabender plasticorder and mechanical property tests. The experimental results show that addition of a small amount of low molecular weight PVC prepared by vibromilling degradation can greatly improve the processability of PVC and enhance the mechanical properties of PVC also.

ISSN:0360-2559    

DOI:10.1080/03602559508009595

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Slow, immiscible, viscoelastic liquid-liquid displacement in a permeable medium is considered. The necessary and sufficient criteria for stability are that the displacing fluid is denser and less mobile than the displaced one. The instability criteria and critical wavelength are found to be the same as those for ordinary viscous liquid-liquid displacements in permeable media.

ISSN:0360-2559    

DOI:10.1080/03602559508009596

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Wood, concrete, steel, and combinations thereof have traditionally been used in civil infrastructure. However, each of these materials has its own drawbacks that range from susceptibility to environmental attack to the large deadweight of the material itself. Steel reinforcing bars, commonly known as rebar, although extensively used for reinforcement of concrete, are susceptible to corrosion and the rapid deterioration of the structure. A number of other factors including chemical and corrosion resistance, better fatigue performance and increased durability in adverse environments, lower overall life-cycle costs, lighter construction material, potential ease of assembly and installation, reduced costs of transporting modules to site, use of modular construction, design flexibility, and overall lower energy consumption have motivated the investigation of the use of composites in civil infrastructure. The present paper focuses on the results of the use of composites as reinforcements in concrete beams. A description of bond behavior is presented as it relates to predictions made about beam failure, as well as to the determination of key design parameters. The results of beam tests are reported and general conclusions drawn as to the need for an appropriate design methodology rather than the acceptance of the approach determined for steel rebar reinforced concrete beams.

ISSN:0360-2559    

DOI:10.1080/03602559508009597

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A series of bi- and trifunctional initiators were tested in the initiation of methyl methacrylate (MMA) polymerization by dilatom-etry; in the first stage, “active” prepolymers with azo and peroxy groups were obtained. In an effort to elucidate some aspects of the decomposition mechanism, an “active” PMMA synthesized with phenylazoformamidoethyl 4-t-butylazo-4-cyanopentanoate was investigated by pyrolitic mass spectroscopy. Finally, these macroazoinitiators were applied in the synthesis of some block copolymers with isoprene.

ISSN:0360-2559    

DOI:10.1080/03602559508009598

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Jute fiber is an important agricultural product. It is one of the most common natural fibers in Third World countries such as India, China, Bangladesh, etc. The jute industry has special importance in the economy of India and continues to be a major traditional earner of foreign exchange. However, it is facing tough competition from the synthetic fibers. Jute fibers find use in sophisticated fields like decorative and furnishing materials such as lamp shades, wall covers, curtains, upholsteries, etc. Today it is the least expensive fiber of mass consumption, at only a fraction of the cost of glass fibers; in terms of volume, jute is now the second most important fiber in the world, next to cotton. In the traditional applications in carpets, ropes, sacks, etc., jute fibers have been partially replaced by synthetic fibers which have some advantages compared to jute. In order to ensure a reasonable return to farmers, nontraditional outlets have to be explored for the fiber. One such avenue is in the area of fiber-reinforced composites.

ISSN:0360-2559    

DOI:10.1080/03602559508009599

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The objective of this work is to minimize warpage of injection-molded parts by deliberately varying each part wall thickness within prescribed dimensional tolerance. The continuous design space of wall thicknesses is explored in search of the optimum wall thickness for given process conditions. The objective function to be minimized is the numeric warpage value, which requires extensive computational time. Once the wall thicknesses are optimized, the warpage is reduced further by optimizing the six significant process variables: injection time, postfill (cooling plus packing) time, packing time, packing pressure, melt temperature, and coolant temperature. As a solution methodology, the modified complex method has been developed and applied in two example parts, where a reduction in warpage of over 70% has been obtained with a moderate number of function evaluations.

ISSN:0360-2559    

DOI:10.1080/03602559508009600

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The Fifth Annual Conference on Flame Retardancy was held May 24–26, 1994, at the Ramada Plaza Hotel, Stamford, Connecticut, USA. The conference was organized by Business Communications Company, Inc., Norwalk, Connecticut (Company President, Mr. Louis Naturman; Conference Coordinator, Mrs. Sharon D. Faust). New materials (polymers, blends, composites), their applications, industry developments, and markets were considered. Specifically, the most important topics were:

ISSN:0360-2559    

DOI:10.1080/03602559508009601

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor