ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Attempts have been made, particularly by American workers, to exploit differences in crystalline and amorphous polymer spectra to determine crystalline/amorphous ratios. In most published work authors have been forced to rely on calibration by other methods, especially density. They have justified the use of the spectroscopic method principally on the grounds of speed in obtaining results. We propose a spectroscopic method, applicable to a number of polymers, which is entirely independent of other measurements. We are thus able to compare our results with those obtained by other methods and have in some cases been able to draw useful conclusions from apparent anomalies. Our method depends upon measurement of pure amorphous bands. We consider these to arise from the multiplicity of rotational isomers present in the amorphous phase. The pure amorphous spectrum of many polymers can be obtained, and by this means an absolute calibration of amorphous content is possible. Crystalline bands cannot be so calibrated; they are dangerous to use quantitatively, although superficially more attractive because of their sharpness. The application of the method to some common polymers including polythene, polyethylene terephthalate, and polytetrafluorethylene is described; the results are compared with values obtained by x-ray and density methods.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1956.120199310
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