Polymerization technique using equimolar amounts of trifluoronitrosomethane and tetrafluoroethylene to increase yield of copolymer is described. Yields were increased by ninety percent and final product displayed better physical properties. Test equipment and chemical reactions for process are described

Glickman, S. A.

English

NASA Technical Reports Server

August 1972	 B72-10418 
NASA TECH BRIEF	
A A 
Ames Research Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Technique for Increasing Yield of 
Trifluoronitrosomethane - Tetrafluoroethylene Copolymer 
It has been demonstrated that an aqueous sus-
pension . polymerization technique using equimolar 
amounts of trifluoronitrosomethane (CF 3NO) and 
tetrafluoroethylene (C2F4) will provide a 68-percent 
yield of a 1: 1 copolymer (CF3NO:C2F4). 
A persulfate-bisulfite redox system was investigated 
for polymerization of equimolar amounts of CF3NO 
and C2F4 in aqueous lithium bromide in an attempt 
to incorporate more than an equimolar amount of 
C2F4 into the copolymer. The reaction was allowed 
to proceed for 48 hours at —35° C, and then for 72 
hours at 10°C. The gum copolymer of CF3NO–C2F4 
which was isolated was found to represent only a 49 
percent conversion. In subsequent experiments, a 
50-percent excess of C2F4 was used. Yields were 
markedly increased, and as much as 90 percent of 
the copolymer was formed; moreover, the. products 
displayed less tack than those produced by equimolar 
ratios of principal reactants. Details of the procedure 
are given in the following paragraph. 
A 250-ml heavy-walled glass reactor was charged 
with 70 ml of 35 percent (by weight) aqueous lithium 
bromide, 2.0 g magnesium carbonate, 0.005 g sodium 
persuifate, and 0.005 g sodium bisuifite. Ten-gram 
portions of CF3NO (0.10 mole) and 15.0-g portions 
Of C2F4 (0.15 mole) were added successively to the 
polymerization vessel; the vessel was kept cool at 
liquid nitrogen temperature. Transfers of the mono-
mers were made by expanding the gases into a cali-
brated volume at a measured pressure, followed by 
condensation at liquid nitrogen temperature. The
sealed reaction vessel was placed in a refrigerated 
bath (-35°C) for 48 hours; then the temperature of 
the vessel and contents was allowed to rise to 10°C, 
kept at 10°C for 72 hours, and finally cooled to 
—35°C. During the reaction period, the mixture was 
agitated by shaking the vessel. The vessel was opened 
cautiously and the suspension of the copolymer was 
allowed to settle. Then the supernatant liquid was 
decanted; the precipitate was washed with water 
and treated with 6N hydrochloric acid until no fur-
ther reaction was noted. The isolated gum was 
washed free of acid and then dried under vacuum 
at 50°C. 
Notes: 
1. No homopolymerization occurs when C2F4 is sub-
jected to the reaction conditions described above. 
2. Requests for further information may be directed 
to:
Technology Utililzation Officer 
Ames Research Center 
Moffett Field, California 94035 
Reference: TSP 72-10418 
Patent status: 
NASA has decided not to apply for a patent. 
Source: Samuel A. Glickman of 
Thiokol Chemical Corporation 
under contract to 
Ames Research Center 
(ARC-10566) 
Category 04 
This document was prepared under the sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000417 2020-03-17T03:38:46+00:00Z


Technique for increasing yield of trifluoroni-trosomethane-tetrafluoro- ethylene copolymer

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