An absolute X-ray method for the determination of the crystalline fraction in polymers based on the comparison of the integrated intensities of some of the low order lines of polymers with those of the completely crystalline standard substances, is described. The crystallinity data are obtained for six polymers: 45.6% for isotactic polypropylene, 73% for polyethylene, 52.1 yo for nylon-6, 50.8% for nylon-66, 32 yo for isotactic polystyrene, and 33.4% for poly-4-methylpentene-1.These data are in a reasonable agreement with the data obtained by the otherx-ray procedures. The accuracy of the method, however, is restricted by the general impossibility to know precisely the structure factors and the corrections to the intensities due to the thermal vibrations of the atoms and lattice imperfections.
ZUSAMMENFASSUNG:Es wird eine absolute Rontgenanalyse zur Bestimmung des kristallinen Anteils in Polymeren beschrieben, die sich auf den Vergleich der integrierten Intensitaten einiger Linien niederer Ordnung der Polymeren mit denen der vollkommen kristallinen Standardsubstanzen stiitzt. Die Daten der Kristallinitat fiir sechs Polymcre wurden bestimmt: 45,6y0 fiir isotaktisches Polypropylen, 73 yo fiir Polyathylen, 52,l yo fiir Nylon-6, 50,8 yo fiir Nylon-66, 32 yo fiir isotaktisches Polystyrol und 33,4 yo fur Poly-4-methyl-penten-1.Diese Daten befinden sich in angemessener Ubereinstimmung mit den durch andere Rontgenmcthoden erhaltenen Werten. Jedoch ist die Genauigkeit der Methode darauf beschrankt, daB es allgemein nicht moglich ist, die Strukturfaktoren genau zu erkennen und Intensitatskorrektuen, die die thermischen Schwingungen der Atome und die Gitterfehlstellen beriicksichtigen, vorzunehmen.
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