' I
H. MOEREMANS d'EMAUS, BRUCE G. BRAY, JOSEPH
J. MARTIN, and LEIGH C. ANDERSON
University of Michigan, Ann Arbor, Mich.
Syntheses of Butadiene-Styrene Elastomers and of Polysulfones by Gamma Radiation a .
Gamma radiation, product of the atomic age, in one aspect of its potential application in the chemical industry T H E . advent of the atomic energy program stimulated many research activities to discover uses for the high-energy radiation made available by the fission products of the nuclear reactors. The use of this radiation as a catalyst in chemical reactions has been shown to be very effective in certain cases (2, 3) and may prove to be advantageous on an industrial scale. I n the absence of fission-product sources and because of the expected use of gamma radiation, the experimental work a t Michigan has been conducted with cobalt-60 sources nominally rated a t 1 and 10 kc. Actual intensity levels during the course of this investigation were about one third the nominal values. I n this study various polymers of butadiene and styrene were produced by gamma radiation. Also polysulfone compounds were obtained by reacting sulfur dioxide and various unsaturated hydrocarbons. The data presented are in most cases not complete for any range of variables. They represent preliminary investigations and are presented to show that radiation does affect the reactions. A more complete study of some phases of this work is being made and will be presented a t a later date.
i
Copolymerization of 1,3-Bvtadiene with Styrene Preliminary investigations have been made on the effect of y radiation upon the copolymerization of 1,3-butadiene and styrene and upon emulsions of 1,3-butadiene and styrene in various soap solutions. These preliminary experiments involved small quantities of reacting materials in glass vials which were given various doses of gamma radiation. The reactions were carried out a t room temperature and under vapor pressure of the butadiene, no shaking or stirring device was provided, and in all cases but one no catalyst or chain modifier was added to the reacting mixture. Equipment. All these investigations were carried out in heavy-walled vials blown from thick borosilicate glass tubing. The diagram of the vials shows their average dimensions; when sealed,
1,3-BUTADIENE: Grade A: 0.4% butane and/or butene, 0.5% acetylene, 0.1 yo phenyl-p-naphthylamine inhibitor, 1,2-butadiene also present in unknown amount. Grade B: 99.77y0 1,3-butadiene; normal butane, butenes, and possibly a trace of acetylenes (0.23%). STYRENE: 500 ml. distilled under vacuum from stabilized reagent-grade styrene, rejecting initial 50 ml. and final 150 ml. NACCONAL AND ALCONOX SOLUTIONS : Saturated solutions in distilled water were prepared in the laboratory and used throughout the experiments. OTHERSOAPSOLUTIONS : Solutions of sodium stearate, calcium stearate, zinc stearate, and lead oleate were prepared from reagent grades and used throughout the experiments. Experimental Procedure. A standard method for loading, irradiating, and handling the vials was adopted and followed in all cases. This procedure was as follows : Emulsifying solutions and styrene were introduced into the vials by pipet and weighed by difference. The vial was connected to the gas-loading rack by
they will safely withstand pressures up to 400 pounds per square inch. The gas-loading rack (schematic diagram) was constructed of heavy borosilicate glass tubing to facilitate loading the vials and was equipped with three loading lines, one of which was used as an emergency vent to the hood. A gasscrubbing column and a gas-drying column, which were incorporated in one of the load lines, could be used to remove the amine inhibitor present in one of the reactant gases used. A cold trap to condense the vapors that might have harmed the vacuum pump was also included in the system. The standard high-vacuum Duo-Seal pump capable of producing a vacuum of less than 100 microns of mercury was used in this work. Dry ice in a 60-40% mixture of chloroform and carbon tetrachloride provided a temperature of -75' C. for the condensing baths in both the cold trap and the cold bath around the vial. Chemicals. Some of the chemicals used in these preliminary experiments were obtained from commercial sources and others were prepared in this laboratory. The analyses and methods of preparation were as follows:
IO
9 8 7
0
6
A
w-5
*
* 4
3 2 I
RADIATION
DOSE, MEGAREP
Propylene-sulfur dioxide copolymerization at room temperature VOL, 49, NO. 11
NOVEMBER 1957
1891
Table 1.
Weight of Dose Weight Charged, Grams product, yield, Dose, Rate, Run Butadiene Styrene Grams yo Rep./Hr. Megarep. A Value 37.4 28.2 0.2 9 3.5 0.0 5.7 166,000 28.1 125,000 5.5 6 0.0 5.5 0 30.44 E O 120,500 Trace 2 1.3 1 .o I49.3 20.78 0.15 6.8 95,000 5 1.3 0.9 E O Trace 0 Control 1 1.8 0.6 31.7 26.92 0.3 7.3 115,000 3 2.1 1.0 79.4 20.4 138,000 31.57 0.9 4 2.4 1.0 33.3 37.2 13.6 148,000 0.9 0.9 7 2.8 403 3.26 17.3 133,000 0.9 1.3 14 2.6 125 6.99 10.2 148,000 0.5 34 1.7 1.1 10.8 0.9 0 Control 15 2.9 1.2 415 3.63 15.5 148,000 0.9 1.0 12 3.4 S O 0 Control 0.9 0.1 13 1.7 Styrene. Possible solution left.
Components Ba
B+S
...
B + S
+ S + KzSzOz + Hz0 + S + KzSz08 + HzO B + S + Nacconal soln. B + S + Nacconal soln. B + S + Nacconal soln. B + S + Nacconal s o h . B + S + Alconox soln.
B B
9 . .
+ S + Alconox soln. a
.
1,3-Butadiene.
Table 11. Components
Ba
+ Sb
B+S B S B S B S B+S B S B S B S B S -jB S B S
+ + + + + + + +
+ Alconox soln.
+ Alconox soln. + Na stearate soln. + Na stearate soln. + Na stearate soln. + Na stearate soln. + Zn stearate soln. Zn stearate soln. + Zn stearate soln.
+ + Zn stearate soln. B + S + Ca stearate soln. B + S + Ca stearate soln. B i. S + Ca stearate soln. B + S + Ca stearate soln. B + S + P b oleate soln. B
...
...
S*
B + S
B
Grade A 1,3-Butadiene-Styrene Copolymerization at 10' to 15" C.
+ S + P b oleate soln. a
1,3-Butadiene.
Grade
0.7 2.9 3.6 2.3 2.4 1.3 4.5 3.3 3.7 2.6 3.7 2.7 2.7 4.6 3.9 2.3
55 1.7 Styrene.
means of high-pressure rubber tubing, and the solution in the vial was allowed to freeze in the cold bath. As a high vacuum was necessary to avoid possible inhibition of the reactions by the oxygen of the air, the whole system was evacuated to less than 1 mm. of mercury pressure. In the first eight runs, the Grade A 1,3-butadiene was loaded directly to the vial through loading line 2 (schematic diagram), In subsequent runs with the Grade A 1,S-butadiene an attempt was made to remove the amine inhibitor that it contained: by using line 1, the gas was bubbled through a 6-V sulfuric acid solution and dried in a calcium chloride tower before it was condensed in the vial. The Grade B 1,3-butadiene was loaded directly to the vial through loading line 2. After introduction of the desired reactants, a check was made on the line pressure by connecting the vial to the vacuum pump manometer. The temperature of the cold bath was low enough so that if sufficient time was allowed for complete condensation to take place, the vapor pressure of butadiene was below atmospheric pressure, and the vial was ready for sealing.
1 892
.
B 1,3-Butadiene-Styrene Copolymerization at 10"
Weight Charged, Grams Run Butadiene Styrene 41 2.0 0.7 40 42 43 46 47 52 53 50 51 59 58 48 49 57 56 54
I
0.9 0.8 1.1 0.8 0.9 0.9 0.8 0.9 0.8 0.8 0.8 0.7 1.2 0.9 0.7 1.0
c
Weight of Product, Grains 0.05 Trace 1.2 0.3 0.8 Trace 0.5 0.3 Trace Trace 2.2 Trace 1.0 Trace 2.7 Trace 2.7
Dose Yield, Rate, yo Rep./Hr. 1.85 140,000
5ZO 15.6 3.5 14.3 E O
10.6 4.1 E O S O
37.3 LZO
16.7 E O
33.8 E O
46.5
0.9
