Document pen5aYDM6pK2d1051wg6VgwKE

of,i ^ y . RESIDUAL VCM STABILITY IN SUSPENSION VINY BOTTLE VS. BAG STORAGE KtUI^Lu JUN 87 1975 R. N. WHEFIER, JR. AUTHOR: R. M. ARNOLD SUPERVISOR: G. F. TACQUARD DATE: Vinyl resins produced at Texas City have routinely been sampled in poly ethylene bags in the production and distribution areas and sent to the laboratory for specification and special analyses, including the analysis for residual vinyl chloride. With respect to the VCM analysis, a resin sample, upon receipt in the laboratory, is placed in a small, two ounce bottle and tightly capped to minimize the loss of VCM prior to actual dissolution of the resin In tetrohydrofuran. Recently, a recommended procedure for the "Sampling and Storage of Test Samples of Vinyl Resins for Residual VCM Analysis" was proposed by Dr. John Brezinskl.1 This procedure is at variance from the established plant procedure in that the proposed sampling of the resin is initially in 4 oz, wide-mouth glass jars which are tightly sealed with an aluminum-lined lid and electrical tape applied to the juncture of the jar and lid. Analysis of the resin Is recommended to be within four hours and in no case later than twenty-four hours after sampling. Accordingly a comparative evaluation of the reconmended and current sampling procedures with respect to residual vinyl chloride in suspension resins has been made. Spot samples of several resin types were obtained from the dryers. Transfer of the samples into 4 oz, wide-mouth bottles as well as polyethylene bags was quickly made. The 4 oz bottles were tightly capped and sealed with electrical tape. The polyethylene bags were tightly knotted leaving essentially no vapor space above the resin. Samples were then with drawn from both bottle and bag after 0, 4, 24 and 48 hours storage at room temperature and analyzed for residual VCM using the current analytical procedure, WC-326-G-1. Results of this comparative evaluation are shown in Table I. The storage stability of suspension vinyl resins with respect to residual VCM is much greater in tightly-sealed sample bottles than in polyethylene bags. Unless resin samples taken for residual VCM analysis are initially stored in tightly-sealed bottles, the loss of VCM from the resin is virtually unchecked until resin dissolution. A graphical comparison of residual vinyl chloride analysis with storage time for each suspension resin evaluated is shown in Graphs I - III. RESINS LABORATORIES UNION CARBIDE CORPORATION CHEMICALS AND PLASTICS DIVISION TEXAS CITY PLANT ucc 068181 2. The data further Indicates that an average VCM loss of approximately 20% occurs In samples stored In polyethylene bags compared to 5% In bottles after a storage time of twenty-four hours (Figure IV). Vinyl resin samples are generally analyzed for residual VCM within twenty-four hours after sampling. RECOMMENDATIONS The routine sampling of vinyl resins by production and distribution personnel in small sample bottles for determining residual VCM would represent a drastic change to present sampling techniques particularly for shipping samples which generally are composites of 3-8 samples. The following proposed changes to current sampling procedures are offered: 1. Minimal delay In sample pick-up, compositing and storage in sample bottles Is given to resin samples which are to be analyzed for residual VCM. 2. Resin samples which are specifically required for process studies Involving residual VCM are initially taken in small sample bottles which are tightly capped and sealed with electrical tape. 3. The < 1 ppm VCM specification on all solvent vinyl (dry) resins has necessitated the sampling and analysis for VCM of the storage . bin(after blending and prior to transfer Into the final shipping container). Generally, solvent resins analyze <0.5 ppm VCM. However, In the event a solvent vinyl bin analyzed >0.8 ppm. It Is reconmended that the bln be resampled and Initially placed In a sample bottle until reanalysis is made. The reanalysis would eliminate possible VCM loss which might have occurred from normal sampling procedures. REFERENCE `Brezinski, J. J., letter to R. N. Wheeler "Sampling of Vinyl Resins for Residual Vinyl Chloride Monomer Analysis," 511, April 17, 1975. /kw UGG 068182 TABLE I I COMPARISON OF VCM STORAGE STABILITY OF SUSPENSION VINYL RESINS BOTTLE VS. BAG SAMPLE CONTAINERS RESIN TYPE QSAL-7 Initial 4-hours 24-hours 48-hours VCM, ppm No. 1 Bottle 259 259 250 247 Bag 259 227 207 130 No. 2 Bottle Bag 1049 1049 1040 944 1013 860 913 769 qspH-7 Initial 4-hours 24-hours 48-hours 877 877 853 838 840 729 828 544 1262 1244 1240 1221 1262 1104 886 654 VSJE-10 Initial 4-hours 24-hours 48-hours 255 255 255 242 227 216 224 158 500 500 490 461 436 409 426 271 UCC 068183 FIGURE I Comparison of Residual VCM Stability of VSJE-iO Sampl a Bottles Tarsus Bafs R e s id u a l VCM, ppa FIGURE II Comparison of Residual VCM Stability of QSAL-7 Semples Bottles v rsus Bags R e s id u a l VCM, ppm FIGURE III Comparison of Residual VCM Stability of Q5QH-7 Samples Bottles versus Bags O; vf R e s id u a l VCM, ppm i FIGURE IV Comparison of % Average Toss of Residual VCM in Suspension Vinyl Resins During Storage In Bottles versus Bags % A verage Toss o f R e s id u a l VCM 1 ii ; m DISTRIBUTION TEXAS CITY Mr. H. P. Brady Mr. M. E. Elsenhour Mr. R. L. Frantz Mr. J. L. Hockersmlth Mr. F. L. Johnson Dr. D. R. Montgomery Mr. W. C. Roeh Mr. K. E. Ross Mr. R. W. Sesler Mr. G. F. Tacquard BOUND BROOK Mr. E. Bell Mr. R. J. Davis Mr. A. E. Donaldson Dr. L. P. McMaster k f i SOUTH CHARLESTON PLANT Mr. C. E. Fry Mr. M. E. Griffith ^1r. R. N. Wheeler TECHNICAL CENTER Mr. J. J. BrezInski NEW YORK OFFICE Mr. G. P. Bigelow Mr. D. E. Hardman Mr. G. T. Scott Dr. A. B. Steele Dr. T. T. Szabo \ <' j u , ,. ,4V> ' / -r -k 1i '\S * L. % : ' \y ' ucc 068188