Depth-dependence of cross-linking on photo-oxidation of polyoctenamer

摘要

Photo-ageing of polymeric materials induces physical and chemical modifications. The non-uniformity of photo-oxidation across polyoctenamer films has been investigated. While a previous study was devoted to the spatial distribution of photo-products, the present paper deals with the heterogeneity of molecular structure changes. Melt viscoelastic experiments provide evidence that molecular weight increases rapidly as photo-oxidation proceeds, involving cross-linking which is characterized as being depth dependent. From our results, we assume that the depth dependence of the molecular structure change of the material through photo-ageing is correlated to the chemical profile in layers beyond 15 mum. (C) 2003 Elsevier Science Ltd. All rights reserved. [References: 27]