Several types of fibrous polyamides were exposed to gamma, ultraviolet (uv), and thermal radiation, singly and in combination, under controlled conditions. The unexposed and exposed specimens were examined by the techniques of solution viscosity, melting point, infrared (ir) spectra, uv absorption and light microscopy. Tensile strength was mea sured in some instances. The combined results give insight into the changes taking place as a result of irradiation. Most polyamides are degraded by long exposure to uv radiation. One was degraded by uv alone and not affected by gamma or heat alone. When exposed to gamma first followed by uv, the degradation was decreased. Simultaneous exposure to gamma and uv gave the same result.
Achhammer, B.G. , Reinhart, F.W., and Kline, G.M., Mechanism of the Degradation of Polyamides , J. Res. Nat. Bur. Stand.46, 391-421 (1951).
2.
Bopp, C.D. and Sisman, O., How Radiation Changes, Polymer Mechanical Properties, Nucleonics13, 51-55 (1955).
3.
Boulton, J. and Jackson, D.L.C., The Fluidity of Nylon Solutions in m-Cresol, J. Soc. Dyers Colourists59, 21-26 (1943).
4.
Ibid., The Fluidity of Nylon Solutions in m-Cresol, Part II, J. Soc. Dyers Colourists61, 40-47 (1945).
5.
Charlesby, A., "Atomic Radiation and Polymers," New York, Pergamon, 1960.
6.
Charlesby, A., Some Radiation Effects on Long-Chain Polymers, Trans. Plastics Inst., London23, 133 ( 1955).
7.
Charlesby, A. , Effect of High Energy Radiation on Long-Chain Polymers, Nature171, 167 (1953).
8.
Colthrup, N.B. , Spectra Structure Correlations in the IR Region , J. Opt. Soc. Amer.40, 397-400 (1950).
9.
DuPont, High Temperature Twins, DuPont Magazine, Sept.-Oct., 1963.
10.
Florin, R.E. and Wall, L.A., Radiation Chemistry of Monomers and Polymers NBS, WADC, Report No. 33 (61 57-14 Project No. 7 (8-7360) Task No. 70347, 1959.
11.
Flory, P.J. , Molecular Weights and IntrinsicViscosities of Polyisobutylenes, J. Amer. Chem, Soc.65, 372-382 (1943).
12.
Hargreaves, G. , NAMATCEN Report No. NAMC AML AE 1076, Final Report TED NAM AE 5293, 18 Dec., 1958.
13.
Hargreaves, G., Radiative Degradation of Nylon 66 as Shown with a Polarizing Microscope, Textile Res. J., 32, 784-785 (1962).
14.
Hargreaves, G., Viscosity of Dilute Solutions of Nylon 66 in CaCl2CH3OH, J. Polymer Letters2, 29-30 (1964).
15.
Harwood, J.J. , Hausner, H.H., Morse J.G., and Rauch, W.G., "The Effects of Radiation on Materials," N. Y.; Reinhold, 1958.
16.
Harmon, D.J. , Effects of Gamma Radiation (Co60) on the Physical Properties of Textile Cords, Textile Res. J.27, 318-324 (1957).
17.
Hays, M.B., Delaware Valley Intersectional Paper, Effects of UV Absorbers on the Sunlight Resistance of Various Types of Nylon, Amer. Dyestuff Reptr.55, P1065-P1071 (1966).
18.
Heyn, A.N.J., "Fiber Microscopy," N. Y., Interscience, 1954.
19.
Hill, R., "Fibers From SyntheticPolymers," London, Elsvier, 1953.
20.
Huggins, M.L. , Viscosity of Dilute Solutions of Long-Chain Molecules. V: Dependence on Solvent, J. Appl. Physics14, 246 (1943),
21.
Huggins, M.L. , "Physical Chemistry of High Polymers," N. Y ., Wiley, 1958.
22.
Kamerbeek, B., Kroes, G.H., and Grolle, W., Thermal Degradation of Polymers, Soc. Chem. Ind. (London) 13, 357-391 (1961).
23.
Kozlov, P.V. , Endrykhovskaya, A., and Kargin, V.A., Investigations into the Temperature Transitions in Synthetic Polymers with Rigid Chains, Dokl. Akad. Nauk. SSSR129, 844-846 (1959), J. Textile Inst. Abstracts51, A225 (1960).
24.
Little, K., The Effect of High Doses of Ionizing Radiations on Organic HighPolymers, A.E.R.E. Harwell , March 1954.
25.
Lothian, M.A. , "Adsorption Spectrophotometry," London, 2nd Ed., Hilger and Watts Ltd.1958.
26.
Melvile, Sir Harry, Twenty-Five Years of Manmade Fibers, J. Textile Inst.71, P382-P391 ( 1960).
27.
NASA Tech Memo, Survey of Photodegradation of Organic Polymers Exposed to Ultraviolet Radiation, NASA-TM-X-59805 19, 1967.
28.
Nichols, J.B. , X-ray and IR Studies on the Extens of Crystallization of Polymers, J. A ppl. Phys.25, 840-847 (1954).
29.
salvin, V.S. , The Effect of Dyes on Light Degradation of Nylon, Amer. Dyestuff Reptr.57, P156-P159 (1968).
30.
Schwertassek, K., Structure of Polyamide Fiber, Faserforsch , Textiltech. 2, 45-53 (1955).
Singleton, R.W., Kunkel, R.H., and Sprague, B.S., FactorsInfluencing the Evaluation of Actinic Degradation of Fibers, Textile Res. J.35, 228-237 (1965).
33.
Stephenson, C.V. and Wilcox, W.S., Ultraviolet Irradiation of Plastics. IV: Further Studies of Environmental Effects on Films and Fibers, J. Polymer Sci. Part A 1, 2741-2752 (1963).
34.
Taylor, G.B. , The Relation of the Viscosity of Nylon Solutions in Formic Acid, J. Amer. Chem. Soc.69, 635-638 (1947).
35.
Tobolsky, A.V. , "Properties and Structure of Polymers," N. Y., Wiley, 1965.
