Degradation and Stabilisation of Polymer

Many kinds of polymers are used in the electronics industries, from polyethylene to so-called super engineering plastics, such as polyethersulfone or polyimide. Almost all of them require additives. The reason for this is either to retain intrinsic characteristics or to extend those characteristics. In order to retain properties, polymers need process and heat stability, thermal stability or light stability. For the acquisition of new function, many kinds of functional additives can be added. Metal deactivators, antistatic agents and flame retardants are just some examples. 

Phenolic AO s and HALS react with oxygen centered radicals 

Ttiiosvneroists and phosphites react with hydroperoxides to yield inactive products (ROH) 

Polymer is degraded by heat, energy, UV or residues of catalyst and generates alkyl radicals. This alkyl radical reacts with oxygen and form peroxy radicals. These peroxy radicals abstract hydrogen from other polymer and forms alkyl radicals and hydroperoxide. The decomposition of hydroperoxide to alkoxy and hydroxyl radicals induces additional decomposition of the polymer chain. In order to stop the radical chain reaction of degradation, stabilisers such as phenolic antioxidant, phosphites, thioether and hindered amine light stabilisers (HALS) are added. 

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FRISCH, K. c., and saunders, j. h. (Eds.), Plastic Foams Part I, Dekker, New York (1972) GEUSKENS, G. (Ed.), Degradation and Stabilisation of Polymers, Applied Science, London (1975) HAWKINS, E. L. (Ed.), Polymer Stabilisation, Wiley-Interscience, New York (1972)... 

G Geiskens (ed.). Degradation and Stabilisation of Polymers. London Applied Science Publishers, 1975. 

Mita, I. Effect of structure on degradation and stability of polymers. In Aspects of Degradation and Stabilisation of Polymers, Jellinek, H. H. G., Ed., New York Elsevier, 1978, 247-294. 

Shlyapnikov YA (1990) Proc Microsymposium Degradation and Stabilisation of Polymers, Stara Lesna, High Tatras, June 1990... 

Al-Malaika S, "Oxidative Degradation and Stabilisation of Polymers", Intern Mater Rev 48 (2003) 165. 

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Chien, J. G W. Hydroperoxides in degradation and stabilisation of polymers. In Degradation and stabilisation of polymers. Geuskens, G. (ed.). London Applied Science Publishers 1975, pp. 95-112... 

W W Wright, in Degradation and Stabilisation of Polymers, ed. G Geuskens, London, Applied Science, 1975, Chapter 3. 

Carlsson D.J. 1993. Degradation and stabilisation of polymers subjected to high energy radiation. In Atmospheric oxidation and antioxidants, Vol. II, Scott G. Ed, Ed. Amsterdam Elsevier. 

Figure 6.2 shows some representative processes for degradation and stabilisation of polymers. Phenolic antioxidants react with peroxy radical and alkoxy radical by donation of hydrogen. Phosphites and thioether act as reducing agent for hydroperoxide, which is converted to alcohol. Hydroxylamine, which is a relatively new stabiliser, acts as hydrogen donor and hydroperoxide decomposer. 

H.H.D. Jellinek in Proceedings of The 2nd International Symposium on Degradation and Stabilisation of Polymers (Abstracts of Reports), Dubrovnik, Croatia, 1978. 

Competitive technique for study of degradation and stabilisation of polymers... 

Degradation and stabilisation of polymers/edited by G. Geuskens New York Wiley New... 

Geuskens G, ed. Degradation and Stabilisation of Polymers. New York Wiley, 1975. Longworth R. In L Elolliday, ed. Ionic Polymers. New York Wiley, 1975, pp. 69-172. MacKnight WJ, Earnest TR. J Polym Sci Maeromol Rev 16 41, 1981. 

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