Fikentscher number

Suspension grade poly(vinyl chloride) Tarwinyl S-60, having the Fikentscher number K = 60.3 and M = 1.02x10, as well as polymethacrylates prepared in our laboratory by suspension polymerization were used throughout this study. The polymethacrylates used were PMMA, PBMA and copolymers MMA/BMA the respective comonomer ratios were 50/50 and 30/70. Molecular weights of all polymethacrylates were similar (M = 9x10 ). 

In North America, relative or inherent viscosities are more frequently used. In Europe, the Fikentscher number (or K number) is more frequently used. Figure 2.1 shows that there is excellent agreement between all three methods of expression of molecular weight influence on viscosity of PVC solutions. 

M. Dunkel and H. Fikentscher, and, of course, "a good organic chemist" (or two) C. Wulff and H. Hopff. The group eventually numbered about fifty with fifteen scientists, and were organized in three sections—synthesis, characterization, and applications—with Mark as the coordinator. In addition by mid-1927, the I. G. could boast of the best X-ray diffraction equipment on the continent. 

Dibromodifluoromethane in ether added slowly with stirring and cooling at — 70° to a Grignard-soln. prepared from butyl bromide and Mg 4-nonene. Y 72%.—This is a simple method for the prepn. of olefins with an uneven number of G-atoms and a centrally located double bond. F. e. s. V. Franzen and L. Fikentscher, B. 95, 1958 (1962). 

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