Accomplishments made during study of coatings are reported. Development of structure/property theory for selecting most appropriate pigments for space vehicle paints is discussed along with improvements made in zinc-oxide pigmented potassium silicate paint

Ashford, N. A.

Gilligan, J. E.

Zerlaut, G. A.

English

NASA Technical Reports Server

December 1972
	 B72-10596 
NASA TECH BRIEF 
Marshall Space Flight 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. 
Investigation of Environmental Effects

on Coatings for Thermal Control 
The advances made in studies on pigmented coatings 
for use in regulating the temperature of satellites and 
large space vehicles may offer significant improvements 
in earth-bound applications. Two techniques are used for 
controlling the temperature of satellites and space 
vehicles: the active technique usually requires both 
electrical power and moving parts; the passive technique 
utilizes surface materials which have appropriate thermo-
physical characteristics. It is due to the passive technique 
that extensive work has been done in the area of 
materials used for the coatings. 
Major accomplishments made during the study of 
coatings included the development of a structure/ 
property theory that relates to the selection of the most 
appropriate pigments for employment as space vehicle 
paints. Also, improvements were made in a zinc-oxide-
pigmented potassium silicate paint and a silicated zinc-
oxide-based silicone elastomer coating, the latter being 
currently used as prime thermal control on numerous 
satellites and spacecraft. The rationale was developed 
for selection of silicone binders that led to the discovery 
of "glass" resin as the most stable resin binder com-
mercially available. Ultraviolet-damage mechanisms in 
semiconductor pigments and also plasma annealing 
have been investigated so that it is understood how the 
reactively-encapsulated zinc orthotitanate can be stabi-
lized against combined ultraviolet-plus-proton irradiation. 
To study properties of pigments, a 12-specimen In 
situ Reflectance/Irradiation Facility (IRIF) and the 
Combined Radiation Environmental Facility were de-
signed and constructed. The Combined Radiation En-
vironmental Facility simultaneously deposits ultraviolet
at 1X to 4X solar-ultraviolet acceleration factors and 
1.2 keV protons from 1.5X to 250X solar-wind ac-
celeration factors. 
Additional contributions of this study include the 
development of stable, reactively-encapsulated zinc ortho-
titanate-pigmented potassium silicate paint having a 
nominal solar absorptance, a s I of 0.1 and a A a s of less 
than 0.01 in 1000 ESH of ultraviolet radiation in 
vacuum. 
Also developed during the study program was a stable 
plasma-annealed, reactively-encapsulated zinc orthotita-
nate paint based on "glass" silicon resin that possesses a 
nominal a of 0.2 and a A a s of much less than 0.01 in 
2000 ESH of ultraviolet irradiation in vacuum. 
Note: 
Requests for further information may be directed to: 
Technology Utilization Officer 
Marshall Space Flight Center 
Code A&PS-TU 
Marshall Space Flight Center, Alabama 35812 
Reference: B72-10596 
Patent status: 
NASA has decided not to apply for a patent. 
Source: G. A. Zerlaut, J. E. Gilligan, and

N. A. Ashford of

lIT Research Institute

under contract to

Marshall Space Flight Center

(MFS-2 1932) 
Category 04 
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
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=19720000595 2020-03-17T03:37:03+00:00Z


Investigation of environmental effects on coatings for thermal control

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