摘要:

Interfacial and surface tensions of polymers are important in the technology of plastics, coatings, textiles, films, and adhesives through their roles in the processes of wetting, adsorption, and adhesion. Because of experimental difficulty due to high viscosity, however, reliable measurements of these quantities were not reported until 1965 for surface tensions [l, 2] and 1969 for interfacial tensions [3, 4]. A body of scattered data has been accumulated in the literature. This review will evaluate, compile, and interpret these results.

ISSN:1532-1797    

DOI:10.1080/15321797408080004

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Polymer reaction engineering has the general goal of providing a polymerization environment optimum in time, temperature, composition, and shear. Various mixing phenomena play a major role in determining this environment, and the study of polymer reactors is in large part a study of these phenomena. The present work is primarily concerned with the time-composition environment in continuous polymerizers. This leads to a study of residence time distributions and the associated concepts of segregation and maximum mixedness. These concepts may be applied to polymer reactors in much the same way as in simpler chemical reactions. The theory can be applied either as a tool for prediction of performance or as a means for explanation of observed results. In polymer reactors, however, the scope of the prediction or explanation should include details of molecular weight and copolymer composition distributions as well as the overall yield of monomer to polymer.

ISSN:1532-1797    

DOI:10.1080/15321797408080005

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

In 1957 three independent papers by Keller [l], Fischer [2], and Till [3] were published which showed that linear polyethylene of high molecular weight formed thin lamellar-like crystals that were quite similar in appearance to those of paraffinic single crystals. These and many subsequent studies have shown that solution-grown polymer crystals are usually about 100 Å thick and that the chains are oriented with their molecular axes perpendicular to the basal plane of the lamellar crystal. Since the crystal is composed of chain molecules whose lengths may exceed by many times the crystal thickness, the conclusion has been drawn that a chain molecule must traverse the lamella several times and in the process must “fold” back on itself. The chain-folding phenomena has now been reported for a wide variety of synthetic organic polymers [4, 5], biopolymers [6–8] including DNA [9], a naturally occurring polysaccharide (amylose) [10], and polymeric selenium [11, 12].

ISSN:1532-1797    

DOI:10.1080/15321797408080006

出版商:Taylor & Francis Group    

年代:1974

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:10.1080/15321797408080003

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor