Biostable Fluorine-Containing Coatings on the Surface of Polymers

We considered the formation of the integrated biostable coating on the surface of several polymers using the original gas-phase fluorination technology. The effectiveness of surface modification of low-density polyethylene (LDPE) and polypropylene (PP) was confirmed by corresponding changes in the absorption spectra of infrared radiation with the modified samples. The gas-phase fluorination quality of ultrahigh molecular weight polyethylene (UHMWPE) and nitrile butadiene rubber (NBR) surfaces was evidenced by the results of scanning electron microscopy (SEM) and energy dispersion analysis (EDS). As was shown with the direct measurements of water and ethyleneglycol wetting angles, the properties differences of the polymer materials with modified surfaces from the initial one correlated well with the change in free surface energy induced by the chemical and morphological transformations under the fluorine and oxygen-containing gas mixtures treatment. The developed technique for the bio-contamination degree quantifying, based on the computer analysis of the corresponding images, allowed us to establish that gas-phase fluorination of the surface approximately doubles the time during which the biofouling of LDPE, PP and UHMWPE with the mixed colony of Rivularia and Stigonema Minutum algae occurs under natural conditions. No positive effect from fluorination was observed for NBR, which was explained, from our point of view, by the difference in the mechanisms of biostability for the considered polymer materials.