摘要:

A polymer can be partially crystalline, such as polyethylene (PE), isotactic polypropene (it-pp), and poly (ethylene terephthalate) (PET), or noncrystalline, such as commercially available atactic poly (methyl methacrylate) (PMMA) and polystyrene (a-PS); partially crystalline polymers are customarily called crystalline polymers. The degree of crystallinity is an important parameter for crystalline polymers. The physical and mechanical properties of polymers are profoundly dependent on the degree of crystallinity. It is well known that the degree of crystallinity can be determined by a variety of physical methods, for example, X-ray diffraction, calorimetry, density measurements, infrared spectroscopy (IR), and nuclear magnetic resonance (NMR). Determination of degree of crystallinity by X-ray diffraction has been claimed to be inherently superior to other methods [1–4]. This review describes the concept and measurement methods of degree of crystallinity with emphasis on X-ray diffraction.

ISSN:1532-1797    

DOI:10.1080/15321799508021751

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effects of high-energy irradiation on the structure, properties, and processing of polymers are of considerable scientific and commercial significance and have been reported in several books and review articles [101]. In this massive literature, two of the major radiation-induced changes reported are crosslinking and degradation, sometimes leading to a loss of crystallinity. In fact, in this literature polymers are generally classified as either “crosslinking type” or “chain-scission type.” In the present review we shall not be concerned with radiation-induced crosslinking, although its existence in many polymers is, of course, acknowledged. Nor will our review cover radiation-induced polymerization or grafting. All these topics have already been adequately covered in the extensive radiation literature, such as the references cited above.

ISSN:1532-1797    

DOI:10.1080/15321799508021752

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In recent years aromatic polyether ketones have achieved a remarkable position among other thermoplastic polymers because of their unique combination of toughness, stiffness, thermooxidative stability, chemical and solvent resistance, electrical performance, flame retardancy, and retention of physical properties at high temperatures [1]. Perhaps the most important advantage offered by the thermoplastics over new toughened thermosets in composites and adhesive applications is the potential of lower cost manufacturing. However, many problems must be solved before thermoplastics find extensive use in aerospace structural applications.

ISSN:1532-1797    

DOI:10.1080/15321799508021753

出版商:Taylor & Francis Group    

年代:1995

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:10.1080/15321799508021750

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor