Polymer Materials as a Source of Corrosion Agents

Comprehending corrosion as failure of materials under the action of the environment, it would be justified to relate this term to fracture of polymer materials under the action of ambient factors, including elevated temperatures, ionizing radiation, UV radiation, ozone, mechanical loads, chemical and biological matter. 

However, the term corrosion is not accepted in relation to polymer materials. Such terms as aging, decomposition and destruction are used for 

Destruction of macromolecules as a result of chemical interactions with the environment leads to the fracture of polymer materials with the formation of active components. Participation of individual macromolecules in destruction processes is dependent upon the amount of the constituent reactive groups. Introduction of substituents of different compositions into the polymer chain changes their stability in thermal oxidation reactions and in response to chemical reagents and moisture effects. 

The presence of multiple bonds in the macromolecule backbone chain greatly reduces its resistance to external effects. Introduction of heteroatoms (nitrogen, oxygen, sulfur) impairs polymer resistance to chemical agents. 

The polarity of macromolecules and the solvent determine the effect of organic solvents on polymer materials. Polymers containing polar groups are resistant to non-polar substances but can swell and be dissolved in polar substances. The polymer permolecular structure exerts a considerable effect on its stability under aging as well. Crystalline polymers dissolve slower than non-crystalline ones, which is due to different diffusion velocities of low-molecular-weight components in the crystalline and amorphous polymers. 

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