Document KJddXbxKxKzbOdBqMM4r0wB2X

AR226-2376 I. X. du Pont de Nemours & Co. (inc.) Code Ho. T 212.200 stic Products and Resins Department Revised: 2-16-76 TV'Page 1 of 2 \ i*" TEFLON- FEP-FL00R0CAR3QH RESIN, AQUEOUS DISPERSICI C- S ja v Determination of Equivalent^C-9 Dispersing Agent Applicability '2/r^ This method is applicable to determining the equivalent^C--9 dispersing agent in FEP dispersion. * II. Unusual Safety Considerations III. Principle . Percent C-9 is determined by titrating FEP dispersion with a solution of cetyltrimethylammonium bromide. , IV. Sensitivity, Precision, and Accuracy . The precision (sigma) of this test based on five runs made on one sample is 0.0005 with an X of 0.125*$ C-9> - .* V. Reagents 1, Cetyltrimethylammonium bromide (CTMAB) 1 g/liter Ptl'W ***"** SR.OtM''Z ) VI- Procedure (RC 19 0.1 2 7 ) 1. Heigh 25 0.01 g FEP dispersion into a 600-ml beaker. 2. Add 20C ml (grad cyl) demineralized water to the dispersion. 3 . Stir the beaker 'using a magnetic stirrer until the dispersion and water are mixed (ca. 30 seconds). h. Fill a buret with 1 g/liter CTMAB solution. Record the reading. 5 . 6- Using the buret, add CTMAB solution to the dispersion constant magnetic stirring. As CTMAB is added polymer to coagulate. When it appears that most of the polymer h a s ^ stop adding CTMAB and then stop agitation a few s gul , _ +n ,,pttle out and observe the supernatant i f t i o a ad, 0 .2 to 0.5 1 * CTMAB. 7. Stop agitation and allow to settle. * Reg. U.S. Pat- Off- RJZ007697 kIk 1 EID933920 page 2 of 2 )i 3. Repeat steps 6 and 7 until the supernatant liquid is perfectly clear. A clear supernatant liquid is the end point of the titration. 9- Record the buret-reading. 10. Find specific gravity of the dispersion and percent solids, using Method T 202.8q 1k 11. Calculate % C-9 and g C-9/g FEP. VII. Calculations 1. Calculation of % C-9 ' ml CTMAB = (step 9 - step 1) ,,,, C-9 = ml CTMAB -- 1000-- x U63 -- ^rrx 36^ vt of 100 dispersion 0.1272 x ml CTMAB vt of dispersion ^fo fCjatL- * 0. I\ SAr < uj-h\\. C-1A vnere: molecular vt C-9 = ^63 molecular vt CTMAB = 36^ 2. Calculation of g C-9/K FEP % FEP = % solids (step 10) % C-9 from step 1, Calculations g C-9 _ % C-9 g FEP % FEP - VIII. References 1. Couture, M. J-, Washington Works Technical laboratory Notebook Mo. 1026, pp 89-89 ' 2. Plastics Department Laboratory Test Method T 202.80b Technical laboratory> 3 - H 71 3. Original Method, Washington Works - +_ better end point and to specif> Revised to reduce sample size to gi ` demineralized instead of deionized vater. O rig in : 1 . S i i i w r g " hods Coordination C o -itto e , M fr K XAi-2939 RJZ007698 EID933921