Medical uses of polymers

Furthermore, concentrates may also be used as conventional additives in the same polymer or in different polymers. In this way a substantive antioxidant (or modifier) system can be produced with very high effectiveness especially under aggressive environments. In comparison, under such demanding conditions, conventional antioxidants will not only lead to premature failure of the polymer but also to dangerous situations such as in the case in food contact application (packaging), medical uses of polymers (artificial joints), and failure of aircraft tyres where human lifes are at risk. 

Other areas where physical loss of additives from polymers is increasing in importance is in food contact applications and in medical uses of polymers. In Europe, legislation is steadily moving toward the situation where loss of any additives, irrespective of their toxicity, may be prohibitive above a certain level. It is, therefore, no longer an academic exercise to retain antioxidants and stabilizers in polymers merely to satisfy unrealistic accelerated tests. It is a practical necessity to improve the substantivity of antioxidants and stabilizers for a variety of quite different practical reasons. 

Popular Plastics and Packaging 47, No. 12, Dec.2002, p.74-9 MEDICAL USE OF POLYMERS - USE OF POLYMERS IN TABLET COATINGS... 

The rate of loss of additives from polymers is determined by migration and volatilisation. Physical loss of additives from polymers is increasingly important in food applications and medical uses of polymers, but also other situations lead to a rapid decrease in antioxidants, such as mechanical extraction of tyres (at temperatures up to 100°C at high speed conditions) or simple solvent extraction of seals and hoses, etc. 

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See also in sourсe #XX -- [ ]

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