Properties of samples are tested, after thermal exposure, and values are compared with unexposed samples. Thermal stability or compatibility ratings of formulated or compounded organic polymers using trade names are made and degree of change in measured properties is assessed. Products are rated compatible, marginal, or not compatible

Campbell, B. A.

Kalfayan, S. H.

English

NASA Technical Reports Server

September 1971	 Brief 71-10362 I NASA TECH BRIEF 
NASA Pasadena Office 
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.
Effects of the Thermal Sterilization Procedure on Polymeric Products 
The effects of exposing commercially available poly- Notes: 
merle	 products	 to	 a	 dry	 reducing	 atmosphere	 at 1.	 A	 report	 covering	 the	 investigations	 includes 
sterilization	 temperatures	 and	 times	 have	 been	 in- a	 tabular	 summary	 of	 the	 test	 results	 for each 
vestigated.	 The term	 "polymeric product" as used product,	 including compatibility ratings. The test 
here specifies a formulated or compounded organic data	 pertain	 to	 thermal	 exposure	 testing	 only, 
polymer sold under a trade name. In its raw or basic and	 are	 average	 values.	 Materials,	 procedures 
state,	 an	 organic	 polymer	 has	 limited	 usefulness, and tests, and compatibility criteria are included. 
but when cured (vulcanized) and, in most cases, when Detailed results of the preliminary screening and 
compounded	 with	 other	 materials,	 it	 can	 acquire the	 thermal	 exposure	 tests	 are	 given	 in	 tabular 
certain desirable properties or responses. form.	 Preparatory	 treatment	 requirements	 for 
.	 Approximately	 160	 proprietary	 products	 were specific products, mixing ratios, pot lives, and cure 
classified	 into	 eight	 categories	 according	 to	 their conditions are included. 
junctions:	 adhesives,	 coatings,	 elastomers,	 encapsu- 2. The	 following	 documentation	 may	 be	 obtained 
lants, films, lubricants, reinforced plastics, and tapes. from: 
Simple, standard tests were assigned to each category, National Technical Information Service 
and more than 6500 specimens were prepared and Springfield, Virginia 22151 
tested. Single document price $6.00 
Prior	 to	 the	 heat	 sterilization	 tests,	 the	 majority (or microfiche $0.95) 
of the products were subjected to a screening program 
to eliminate those with poor thermal stability. The Reference:
 
program	 consisted	 of a 40 hour exposure	 to dry NASA-CR-80434	 (N67-13099),	 Effects	 of
nitrogen at a temperature of 422 K. About 20 prod- the Thermal Sterilization Procedure on Poly- 
ucts	 were	 thus eliminated. The remaining products meric Products 
were	 exposed	 to	 the	 heat	 sterilization	 test,	 which Patent status: consisted of three 40 hour exposure cycles at 422 K 
in dry nitrogen. No patent action is contemplated by NASA. 
After	 thermal	 exposure,	 the	 properties	 of	 the Source: Dr. S. H. Kalfayan and 
samples were tested, and the values were compared B. A. Campbell of 
with those obtained for unexposed samples. Ratings Caltech/JPL 
of	 the	 thermal	 stability	 or	 thermal	 compatibility under contract to 
of the products were then made, assessing the degree NASA Pasadena Office 
of change in the measured properties. Accordingly, (NPO- l 1688) 
products	 were	 rated	 compatible,	 marginal,	 or	 not 
compatible.
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. 
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Effects of the thermal sterilization procedure on polymeric products

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