| 摘要 |
<p>1291957 Analysis of polymerisation medium TOHO BESLON CO Ltd 7 April 1970 [8 April 1969] 16477/70 Heading B1X [Also in Divisions C1 and C3] The following three procedures are used to characterise the purity (with respect to organic impurities) of a concentrated salt solution comprising zinc chloride, which solution is used as recycled solvent in the polymerisation; and subsequent spinning, of acrylonitrile:- (a) A 5ml sample of the salt solution is treated with alkaline N/20 K 2 MnO 4 , then mixed with sulphuric acid, MnSO 4 and N/20 (NH 4 ) 2 Fe(SO 4 ) 2 and titrated with K 2 MnO 4 . A purity value is then calculated according to a given formula. (b) A procedure similar to (a) is used except that no MnSO 4 is added (c) A 10 ml sample of salt solution is mixed with potassium chromate and Mn SO 4 solutions. Diphenyl carbazide and HC1 acid are then added, and absorbance is measured on a colourimeter at 550 mu. A correlation curve gives the amount of potassium chromate used, and a purity value is then obtained.</p> |
