Properties of polymer for conformal coating for electronic circuitry are described. Nitroso fluorocarbon polymers were selected for application. Chemical reactions for production of polymers are discussed. Technique allows regulation of crosslink densities, molecular weight, and viscosity

Marcellis, A.

Mayes, N.

English

NASA Technical Reports Server

August 1972 - 
•	 NASA TECH BRIEF 
Marshall Space Flight Center 
B72-10493 
H 
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be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Functionally Terminated Liquid Nitroso 
Fluorocarbon Terpolymers 
In a developmental program in which the objective 
was to obtain a polymeric conformal coating for elec-
tronic circuity, the requisite properties for the material 
included transparency, flexibility and low modulus of 
elasticity at 208K(-65 0C), workable viscosity, adequate 
application life, good adhesion, and nonflammability. 
Nitrosofluorocarbon polymers were selected for the 
application because prior screening pointed out that 
these polymers satisfy many of the desired properties. 
Acyl fluoride terminated liquid polymers were ob-
tained by the ozonolysis of unsaturated terpolymers 
made from CF 3 NO, C 2 174 , and C4 17 6 . The ozonolyses 
were conducted in high yield using a fluorocarbon solu-
tion of ozone at elevated pressures. The unsaturated 
terpolymers containing backbone to pendant unsatu-
ration iii 7:1 ratio were prepared both in bulk and 
solvent systems with 5 and 10 mole-% hexafluoro-
butadiene. The liquid acyl fluoride polymers were 
easily converted to the corresponding carboxylic acid, 
ester, or amide on treatment with the requisite reagents. 
Reduction of the liquid, ester-terminated polymer to 
the alcohol was successfully achieved by means of lithium 
aluminum hydride. The liquid carboxy polymers were 
reacted with ethylene oxide to give the hydroxyethyl 
ester terminated materials. In similar fashion, the liquid 
carboxy terpolymer of CF 3NO, C 2 F4 , and ON(CF 2 )3
-COOH yielded hydroxyethyl derivatives. The ozonolysis 
is fast, simple, and does not introduce impurities that
would be difficult to remove and would cause problems 
during curing. A variety of functional groups can be 
introduced into the polymer. The technique also allows 
the regulation of cross link densities, molecular weight, 
and viscosity. Relatively high yields are obtained in 
comparison to other methods. 
Notes: 
1. Information concerning this innovation may be of 
interest to the chemical, rubber, and plastics in-
dustries. 
Requests for further information may be directed to: 
Technology Utilization Office 
Marshall Space Flight Center 
Code A&TS-TU 
Huntsville, Alabama 35812 
Reference: B72-10493 
Patent status: 
No patent action is contemplated by NASA. 
Source: N. Mayes and A. Marcellis of 
Thiokol Chemical Corporation 
under contract to
Marshall Space Flight Center
(MFS-2 1539) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Category 04 
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000492 2020-03-17T03:40:05+00:00Z


Functionally terminated liquid nitroso fluorocarbon terpolymers

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