Development of a new software for the X-ray structural analysis of polymer crystals by utilizing the X-ray imaging plate system

✍ Scribed by Kohji Tashiro; Hitoshi Asanaga; Kiyotaka Ishino; Ryoko Tazaki; Masamichi Kobayashi

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 670 KB
• Volume: 35
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(199708)35:11<1677::aid-polb3>3.0.co;2-q

✦ Synopsis

A software and some useful tools have been developed for identifying individual x-ray reflectional peaks recorded with an x-ray imaging plate system. These techniques were applied to analyze the crystal structure of uniaxially oriented polymer samples. Characteristic features of the present method may be summarized as follows.

(1) The indexing of the observed reflections and the determination of the unit cell parameters can be made easily on the display of the computer. (2) The integrated intensity of the individual component of the overlapped reflections can be evaluated quantitatively through the curve separation technique. The R merge 's for the equivalent reflections were 5-6%, indicating the exact evaluation of the integrated intensities.

(3) The thus obtained reflectional data were successfully utilized for the extraction of the initial structural models by the direct method. The actual applications have been made for orthorhombic polyethylene, trigonal polyoxymethylene, and isotactic polybutene-1, giving the refined crystal structures including even the positions of hydrogen atoms in some cases. The reliability factors were 12, 5, and 15%, respectively, for these three polymer crystals.