Ozone, polymeric materials

The study of the polymer degradation is complicated by their structural peculiarities on molecular and supramolecular level and diffusion effects. It is difficult to find simple model reactions for clarification of particular properties and for the express examination of the proposed assumptions. An exception, in this respect, is the ozone reaction with C=C bonds, whose mechanism has been intensively studied and could be successfully applied upon ozonolysis of polymeric materials [28]. 

In general, polymeric materials which have double bonds in their polymer chain are susceptible to ozone attack. The results of optical microscope studies with the ozone treated sample specimens did not reveal any surface crack(Table 3). 

A wide array of surface modification techniques, ranging from simple to sophisticated, wet to dry, and vacuum to nonvacuum, are available for a host of polymeric materials. They include plasma surface treatment laser surface treatment corona, flame, UV, ozone, UV/ozone, photochemical, photografting, chemical grafting, and chemical methods of stuface modification and modification of polyamide surfaces by microorganisms [7]. 

The rubber-modified aromatic polymeric materials, for example, high-impact polystyrene (HIPS) and acrylonitrile-butadiene-styrene (ABS) are the least stable because of the rapid photooxidation of the rubber component, which sensitizes the polymer to further oxidation. Diene-based rubbers are also susceptible to degradation by ozone, which causes chain scission of the main-chain... 

The present research shows the high aggressiveness on the polymeric material and articles and it specially shows the aggressive factors of the humid and tropical climate of Cuba on the robbers the different and more significative atmospheric factors, that is to say (temperature, solar radiation, ozone concentration) were supplied by the Institute de Meteorologia de la Repiiblica de Cuba (The Institute of Meteorology of the Republic of Cuba). The samples of the tested rubbers, especially elaborated with no antioxidant protections were made using the coded rubber, used by the Rubber enterprise Union with the number 471. 

Action of Ozone on Polymeric Materials AND Rubbers Articles... 

In the following frame the differences between the two seasons regarding ozone s concentration have been stated. There is a dry season, which is (winter time), with low temperatures and not very much of rain, but a higher concentration of ozone and on the other hand we have the rainy season (summer period) with high temperatures and a lot of rain, but lower concentration of ozone and effects of sun radiation on polymeric materials. 

The ozone action [92, 102] is very important for the utilization of polymeric materials in various domains, especially in strong electric fields. The peculiarity of the ozone oxidation is short kinetic chain, high radical concentration, greater share of the ozone with intermediate radicals, as well as the localization of the process at the surface and in amorphous regions. For example, the following reactions can take place ... 

Determination of ozone solubility in polymeric materials, Chem. Eng. J., 138, 172, 2008. 

Much has been written about the effects of ultraviolet (UV) radiation on polymeric material and in particular polyolefins. While UV radiation still comprises a relatively small portion of the total radiation found in sunlight that reaches the earth s surface, the acceleration of the deterioration in the earth s ozone layer over the last several decades dictates that subsequently outdoor durables will be exposed to even higher doses of UV radiation than previously realized. 

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