August 1953
TABLEIV.
INDUSTRIAL AND ENGINEERING CHEMISTRY CONVERSIONOF AMMONIUMFORMWYOMING BENTONITE (0.3%) TO CALCIUM FORM (Dowex-50 column with 10 X
11/2
inch bed) Conversion of Clay,
Flow Rate, Ml./Min.
Sample NO.
% 100 100 94 89 65
The data presented i n Tables I through Vindicate that columns of ion exchange resins of the strong-acid type can be successfully employed t o accomplish various degrees of conversion of Wyoming bentonite t o a number of ion forms. By appropriate selection of operating conditions, complete conversion t o a desired ion form can be accomplished. A number of.other clay minerals of the montmorillonite series have been converted by this same method with results substantially the same as those found for the Wyoming bentonite. The behavior of the conversion to hydrogen is exceptional as indicated in Table 111. This may be due to both the very high mobility of hydrogen ions i n solution and the fact that, in equilibrium with solutions containing both ammonium and hydrogen ions, the clay exhibits a great preference for hydrogen.
v.
CONVERSION O F AMMONIUM FORM WYOMING BENTONITE (0.3%)TO MAGNESIUM FORM (Dowex-50 column with 10 X
1’/2
inch bed) Conversion of Clay,
Flow Rote, Ml./Min.
Sample
No. 1
%
100 99
10 10
2
the efficiency of column conversion t o some other ionic forms, a bentonite suspension, 0.01N, in electrolyte was completely converted t o the ammonium ion form, then passed through the various ion-form columns, and analyzed for ammonium t o determine the ammonium transfer in the process. The data for the efficiency of conversion to the hydrogen, calcium, and magnesium forms are summarized i n Tables 111, IV, and V. DISCUSSION
62 67 74
TABLE
1783
LITERATURE CITED
(1) Lewis, D. R., API Research Project 49, Sect. 3 , Rept.
No. 7 ,
New York, Columbia University Press, 1951. ( 2 ) Wiklander, L., Ann. R o y . Agri. CqZZ. Sweden, 16, 154-62 (1951).
mately 0.01N in electrolyte for subsequent column conversion experiments. Because of the tendencies of the multivalent cations and hydrogen ion to flocculate the clays, it was necessary to use very dilute suspensions when converting t o these ion forms. To determine
RECEIVED for review April 30, 1952. ACCEPTED M a y 11, 1953. Presented before the Division of Colloid Chemistry, a t the 121st Meeting of the AMERICAXCHEMICALSOCIETY,Buffalo, N. Y . , ?arch 1952. Publication 18, Exploration and Production Research Laboratory, Shell Development Co., Houston, Tex. 0
Reaction of Chlorotrif luoroethylene
with Oxygen ROBERT L. MYERS, Research Laboratory, General Electric Co., Schenectady, N . Y .
A
STUDY of the reactions of chlorotrifluoroethylene in the presence of water was conducted as part of a program to investigate the suspension polymerization of this monomer. Caird and Goldblum ( 1 ) observed t h a t in aqueous polymerizations a portion of the chlorotrifluoroethylene was hydrolyzed t o give acidic products containing chloride, fluoride, and oxalate ions. It was found in this work t h a t in t h e presence of pure, degassed water chlorotrifluoroethylene was completely stable for indefinite periods. The addition of a nitrogen atmosphere had no effect, nor did the presence of dilute acids. The presence of bases induced a hydrolysis t h a t presumably proceeded via the addition of water, resulted in a consumption of the base, and produced fluoride ion but no chloride ion. Although not isolated, it is assumed t h a t chlorofluoroacetic acid was produced, according to the following scheme: R
R
/-
-\
’
C=C
C1
-
r p
+ HOH +
OH-
I H-C-C-F -\ I
Pl
/-
1
P -.,H-&-C
F ‘
dl F
’
I / /
A1
F
U
H-C-C
6
+ HOH
I
+ H-C-C
&I
’
/
U
\OH
+ HF
This is analogous t o the base-catalyzed addition of alcohols reported by Park ( 4 ) and coworkers, except that the adduct is unstable in the presence of water and is hydrolyzed t o yield t h e acid. In the presence of oxygen and water a rapid reaction occurs. The reaction of halogenated olefins with molecular oxygen is not new. Swarts (6) reported that (sym)-dibromodifluoroethylene reacted exothermically with oxygen t o produce the rearranged dibromofluoroacetyl fluoride. This product was readily hydrolyzed to dibromofluoroacetic acid. Joyce ( 2 ) disclosed that tetrafluoroethylene, water, and oxygen reacted t o give a highly acidic solution containing much fluoride ion, in addition t o polymeric tetrafluoroethylene. Miller ( 3 )also disclosed a polymerization technique for chlorotrifluoroethylene t h a t consists of absorbing oxygen at low temperatures t o form a monomer peroxide, which is used t o initiate polymerization a t higher temO perature. /-
+ HF
F‘
REACTION RATES
In the work discussed in this paper, chlorotrifluoroethylene was found to react with oxygen at room temperature, a t autogenous pressures, and in the absence of light, t o give a compound that, on hydrolysis, yields oxalic acid, hydrogen fluoride, and hydrogen chloride. A small amount of a water-soluble peroxide is also
Vol. 45, No. 8
INDUSTRIAL AND ENGINEERING CHEMISTRY
1784
formed in the hydrolysis step, and if the system is maintained for extended periods a small amount of polymer is formed. The rate of the reaction is illustrated in Figure 1. I n the absence of a liquid phase of chlorotrifluoroethylene, the reaction becomes unmeasurably slow. On the other hand, in the presence of liquid monomer the reaction requires approximately 1 hour; when water is present, t h e reaction is over in 6 minutes. This
T.4BLE
O F OBSERVED P R O D U C T S I. RELATIONSHIP
bI0lP.s x 1 0 - 3
Product Oxygen added Oxalate
IO
Figure 1.
20
15
25
30
35
45
40
TIME, MINUTES
50
55
60
65
70
Rate of Reaction of Chlorotrifluoroethylene w i t h Oxygen a t 25" C.
may be only a solubility effect, but it is possible that the water plays some other role. This reaction exhibits characteristics of a free radical reaction, in that an induction period is sometimes observed when the reaction is run in a stainless steel cylinder, and the cylinder has become poisoned with use. When water was present, no induction period was ever observed, nor was any apparent when the reaction was run in sealed glass tubes.
...
4.84 4.75 4.90 21.2 36.6 35.6 0.006
c1F-
Total [ H I + 2 , F-, c1-, 2czo
