摘要:

Molecular transport of oxygen (O2) and nitrogen (N2) through polymer films has been one of the major thrust areas of research over the past several years. With increasing demand for the use of synthetic polymers in engineering, medicine, surgery, separation science, agriculture, etc., different polymer backbones exhibiting superior transport properties have been synthesized. A great deal of effort has been focused on the surface modification of films in addition to introducing a variety of favorable functional groups on the polymer backbones which facilitates easy transport of gases, such as oxygen and nitrogen, and their separability.

ISSN:1532-1797    

DOI:10.1080/15321799108021922

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

There are no two opinions about the fact that organic polymers play an important role in day-to-day life. These organic polymers are, in general, flammable and are the main suppliers of fuel to the combustion in flame hazards. Investigation reports [1] on fire hazards ascertain that one of the major factors for rapid fire and smoke development is combustible materials including polymers. State-of-the-art fire-resistant and flame-retardant polymers begins when safety-conscious governments, industrial firms, and consumers are highly concerned about the fire hazards of polymers. Tomorrow's safety is today's research. As a result of research, a number of methods and chemicals have been investigated for producing flame retardant polymers and are well documented [2–7]

ISSN:1532-1797    

DOI:10.1080/15321799108021923

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

In a typical suspension polymerization system, one or more water-insoluble monomers containing oil-solube initiator(s) are dispersed in the continuous aqueous phase by a combination of strong stirring and the use of small amounts of suspending agents (stabilizers). Suitable conditions of mechanical agitation are maintained while the monomer droplets are slowly converted from a highly mobile liquid state, through a sticky syrup-like dispersion (conversion 20–60%), to hard solid polymer particles (conversion > 70%) [1–3]. The stabilizers hinder the coalescence of the monomer droplets first, and later stabilize tHe polymer beads whose tendency to agglomerate may become critical when the polymerization has advanced to the point where the polymer beads become sticky.

ISSN:1532-1797    

DOI:10.1080/15321799108021924

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

What cannot be achieved by single materials has been realized through combinations of materials. The modern world is very much aware of fiber-reinforced plastics in which strong fibers, both natural and synthetic, are used to reinforce plastic resins. The main advantage of this combination is an increase in the stiffness-to-weight ratio, which is very important in the aerospace industry [1, 2]. Speciality fibers like glass, carbon, and high temperature fibers have formed the integral part of high performance fiber reinforced composites with resin matrices such as epoxies, bismalamides, polyimides, viny1 ester, and to a growing extent, a number of thermoplastics.

ISSN:1532-1797    

DOI:10.1080/15321799108021925

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A thorough understanding of the structure physical/mechanical properties of the polymers has made possible the molecular design of macromolecules for specific application needs. Several methods exist for polymer synthesis and processing. When it concerns homopolymers, each polymer structure is identified with a particular method for its realization. Depending upon the situation, one or more of the methods (polycondensation, cationic, anionic, or free radical technique) is sometimes resorted to. Each process has its own merits and demerits. The condensation method is applicable to only a few cases of condensation monomers. A variety of vinyl and cyclic monomers are polymerized by anionic and cationic processes. These processes have obvious disadvantages in the sense that they warrant rigorous polymerization conditions like the need for ultrapure monomers, absolute moisture/oxygen free atmosphere, and cryogenic temperatures which are often difficult to realize on an industrial scale. A recent trend in polymer preparation is therefore directed toward a free radical method. The method has the advantage that practically all vinyl monomers can be homo or copolymerized under relatively mild conditions. Further, there is often good control over the reaction parameters governing the kinetics of polymerization, and hence on the molecular characteristics of the resultant polymers.

ISSN:1532-1797    

DOI:10.1080/15321799108021926

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

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

ISSN:1532-1797    

DOI:10.1080/15321799108021921

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor