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FINAL REPORT SUSPENSION VINYL RESINS: STUDIES CF COMPOSITION-MOLECULAR WEIGHT- AUTOGENOUS PRESSURE RELATIONSHIPS | RfcCtlVED ; ! FE3 3 1366 | | R. N Wheel ' l FOR VINYL CHLORIDE/ETHYLENE COPOLYMERS Authors; D. E. Richardson G. G. Harkreader Date: January 28, 1966 Project No.: 320 L 10 File: 819-2513 SUMMARY A series of polymerizations was made in the Suspension Vinyl Resins Pilot Plant to determine the capabilities of existing production auto claves to prepare vinyl chloride-ethylene copolymers. These copolymers can he produced at rates similar to FVC homopolymer, and the maximum concentration of comonomer is a function of the autoclave design pressure and the desired in herent viscosity of the resin. The data are presented graphically in Figure I. Previous pilot plant studies shoved that resin particle characteristics of these copolymers are determined primarily by the suspending colloid, the effect of the ethylene being generally to increase porosity. The composition-process relation ships presented here should be sufficiently accurate for direct use in predicting production capabilities. 'INTRODUCTION There is a need for a concise presentation of Union Carbide's capability to produce vinyl chloride/ethylene copolymer in the existing equipment, since the introduction of the first development samples cf Process -11 resins, there has been frequent discussion of how many grades cf J-hese materials to offer and what range of compositions could be produced in existing suspension polymerization facilities. This report covers the results of a program aimed at providing management with the facts necessary to relate marketing plans to production capabilities. DISCUSSION The Texas City Suspension Vinyl Resin Unit consists of three lines having autoclaves with different pressure ratings. The East line comprises 5 autoclaves with 200 psig rating and 1 autoclave with 300 psig rating. The North line contains 9 autoclaves with 220 psig rating. The South line con tains 6 autoclaves with a 330 psig rating. Also, an expansion of the South line by k additional 330 psig autoclaves is in progress. With these limitations in mind, a series of runs was made at four different polymerization temperatures to establish the maximum comonomer which can be incorporated into the polymer at each of these molecular weights without using a molecular weight degrader. The results of these runs and their relationship to plant operation are discussed below. Research and Development Department Chemicals Division Union Carbide Corporation ucc 061671 2 Procedure There were two groups of runs in this program. In the first case, the monomers were charged and the reactions were conducted at autogenous pressure until the pressure reached 29O psig, at which time the autoclave was vented to maintain 290 psig. In the other case, the polymerizations were conducted at a constant pressure equal to the autogenous pressure at the begin ning of the run by automatically venting the excess pressure as the run pro gressed. All of the runs in this program were made with a Process -7 recipe, 'using 0.145$ Cellosize WF-300, 0.048$ Methocel 15 and 0.125$ sodium bicarbonate , based on the vinyl chloride. The procedure consisted of preparing the autoclave by an evacuation technique to remove the oxygenj charging the water, suspending agent and buffer with the agitator running} cooling the mixture to a specified temperature} charging the vinyl chloride and catalyst with the agitator stopped and then adding ethylene with the agitator running until a specified pressure was maintained at a predetermined temperature (normally 4Q*C) for 15 minutes. When this was completed, the heat-up cycle was commenced. The charge size was adjusted to produce an 80/20 liquid/vapor ratio at the operating tempera ture to correspond to production practice. In the runs at constant pressure, the pressure controller maintained the desired pressure by venting the auto clave vapor phase. The volume of vented gas was measured with a wet test meter and two spot samples were obtained from each of four runs for composi tion analyses. The polymerization was continued until the autoclave pressure decreased by 15 psig, after which the run was terminated and the resin recovered. Results The results of these runs are shown in Table I. The properties of the resin from the runs were very similar and were in the expected range for a resin produced with the Process -7 recipe except for lower apparent density. Quality of the resins produced was generally good, although no particular effort was made to maintain high quality. The indication Is that no quality problems are introduced by the use of ethylene. The relationship between inherent viscosity, comonomer concentration and reaction pressure is presented in Figure I. This graph also shows the dif ferences in comonomer concentration when using the constant pressure technique and the constant charge technique. In the case of operating at 300 psi to produce QXQQ, it would be possible to add 2.3$ comonomer by the constant pres sure technique but only 1.7$ by constant charge technique. The vent gas from the autoclave by the constant pressure technique contains about equal concentrations of ethylene and vinyl chloride. Seven samples of the vent gas were analyzed by the mass spectrometer. Calculations showed that 4.0 to 5.3$ of the original vinyl chloride charged was removed by the venting procedure. Therefore, it will be desirable to provide a recovery system for this vent gas. ucc 061672 3 The ethylene exhibited some retarding effect on the reaction rate but this was easily compensated by the use of additional catalyst. Based on these development studies, the VCl/ethylene copolymer can be produced at the same approximate productivity as FVC homopolymer and by any of the homopolymer process recipes. ATTACHMENT ucc 061673 ;in Type :rt No. ripe: Charge, lbs. c?H4 (Press./Tenp.) Cat. type Cone. >erating Conditions; Temperature, *C Pressure, psig initial max inrun Vent, cu.ft. Reaction time, hrs. roduct: Screen si2e thru Recovery, % rr-.ln Analysis; Inherent Viscosity Comonomer, Apparent Density, lb/cf ICMT Clear HRP Respro 17.5 mil 10 mil /STM Conductance Ford Dry Blend, min. Median Particle Size, Screen, ^ thru: 40 mesh 60 n 00 " 100 " l4o " 200 " 270 " pilot plant data for vci/ethylene copolymer studies qxom-7 10-65-1 4200 100/Ho DLP 0.55 QXOM-7 10-65-2 4200 l4o/40 DLP 0.35 QXOM-7 10-65-3 4200 100/40 DLP 0.33 QXCM-7 10-65-4 4200 160/40 DLP 0.33 QXOH-7 10-65-5 4200 100/40 DLP 0.10 55 144 164 None 7-3/4 40 95 76 55 180 228 None 7-3/4 40 95 84 55 232 290 Slight 9-1/4 40 97 06 55 216 288 None 8-3/4 40 91 86 65 183 194 None 6-1/2 40 97 75 .982 .285 51.5 98 2 0 2 0.65 *.5 142 .978 .815 31.0 116 2 0 5 0.95 5.1 168 .969 1.41 29.O 117 4 0 19 0.75 2.7 160 .962 1.11 30.2 110 2 0 19 0.45 2.8 160 .775 0.30 34.2 104 3 2 12 4.5 178 100 100 100 83 82 33 22 11 95 74 100 78 33 10 3 0 99 69 34 10 3 2 100 97 53 14 3 l QXOH-7 10-65-6 4200 l4o/UO DLP 0.10 65 234 283 None 7-3/4 20 90 75 .759 1.13 34.8 90 4 0 200 3.2 186 92 44 29 18 7 5 QXOQ-7 10-65-7 4242 100/40 IPP 0.10 45 114 127 None 6-1/4 20 99 80 1.205 0.27 38.2 84 5 0 15 4.1 182 100 98 42 25 13 10 QXOQ-7 10-65-8 4242 140/40 IPP 0.10 45 159 219 None 4-1/4 20 99 77 1.176 0.79 28.5 100 2 1 6 3.0 177 100 94 27 9 3 2 QXOQ-7 10-65-9 4242 l8o/40 IPP 0.10 45 201 291 None 5-1/4 20 99 77 1.134 1.55 27.1 110 2 0 18 2.2 186 100 97 39 13 4 3 qxoe-7 10-65-10 4106 100/40 DLP 0.06 75 225 240 None 6 ,T O 60 ~O' C<D0 Large 0.621 0.18 37.6 10 2000+ 5000+ 8.8 Not recovered 1 TABLE I (Co'-Ainued) PILOT PLANT DATA FOR VC1/ETHYLENE COPOLYMER 1IES Rccin Type Run No. Recipe: Charge, lbs. (Press./Temp.) Cat. type cone. QXOE-7 QX0H-7 10-65-11 11-65-6 4106 l4o/4o DLP 0.06 4200 140/40 DLP 0.10 QX0H-7 11-65-7 4200 160/40 DLP 0.10 QXOM-7 11-65-8 4200 l80/40 DLP 0,10 QX0M-7 11-65-9 4200 200/40 DLP 0.33 ycoQ-7 0Z0Q-7 .1-65-10 11-65-1 J.200 220/40 LLP 0.33 4242 180/30 1PP 0.03 Operating Conditions: Temperature, C Pressure, psig Initial maximum Vent, cu.ft. Reaction time, hrs. 75 280 290 mod. 7 65 232 500 7-1/2 65 258 638 8-3/4 65 285 569 9-1/4 55 261 740 9-3/4 55 290 743+6-3/4 45 243 525 5 Product: Screen size it thru Recovery, 56 Not recovered 20 20 20 20 20 20 contaminated 98 78 100 100 100 100 79 81 78 81 81 71 Resin Analysis: <f,Inherent Viscosity Comonomer, Apparent Density, lb/cf ICMT Clear HRP Respro 17.5 mil 10 mil ASM Conductance Ford Dry Blend, min. Median Particle Size, Screen, < thru: 40 mesh 60 " 80 " 100 " l4o " 200 " 270 599 .96 27.1 8 57 768 -- 5-0 255 99 64 8 1 0 0 .748 .71 53.1 101 2 0 13 0.40 -- 250+ 96 4l 17 7 1 0 .769 1.25 34.3 110 3 6 65 0.40 ____ l4o 93 85 78 53 19 7 .769 1.36 30.1 95 3 5 80 0.45 __ 173 100 99 57 25 10 5 .933 1.44 28.8 109 3 0 60 1.0 4.1 175 100 99 69 25 S 3 .858 1.48 27.5 113 5 0 195 1.5 -- 230 99 42 12 3 1 0 1.067 1.51 26.7 122 10 0 5 -- -- 191 100 100 34 12 5 3 ucc 061675 061676 i DISTRIBUTION Texas City Mr. W. D. Bush Mr. 0. T. Carlisle/Mr. D. E. Richardson Mr. J. F. Erdmann Mr. J. H. Field Mr. A. P. Fisher Mr. N. A. Gimber Mr. 0. A. Holt Mr, J. L. Hockersmith Mr. R. C. Robinson Mr. H. H. Savage Mr. J. C. Schlichter 3ound Brook Mr. F. A. DeMelio Mr. G. G. Himmler Mr. C. J. Luz, Jr. Mr. K. V. McCullough Tarrytovn Mr. P. T. McCoy New York Office Mr. F. D. Dexter Mr. C. R. Field Mr. H. W. Greenhood Mr. W. H. Joyce Mr. J. R. Wilkinson Technical Center Dr. F. E. Bailey, Jr. Dr. J. J. Brezinski Mr. D. L. Engle Dr. J. E. Glass Mr. R. J. Hanna Mr. W, S. Lanier Dr. w. R. Manning Mr. W. E. Whitehurst South Charleston Wheeler uco 061677