Fluorine-containing polymers modification

Among the fluorine-containing polymers of commercial importance, our polymer of choice was PCTFE, the homopolymer of chlorotrifluoroethylene. The reason for choosing this polymer was the assumption that the chloride group would have sufficient reactivity to allow chemical modifications (Equation 1), but, in the most likely case that such modifications were incomplete, would be inert toward the ultimate reagents and substrates when the functionalized polymers were applied in their subsequent uses in carrying out organic reactions. 

Modifications of the Cel Polymer Electrolyte Based on Fluorine-Containing Polymers... 

In-situ treatment, on the other hand, uses existing polymer processing equipment to apply the desired fluorine-containing gas to the polymer in question. Of course, there has to be some modifications of the processing equipment. The... 

Since it was observed that fluorine contamination was a possibility and had potentially detrimental effects as described in Chapter 10, the excellent primer adhesion achieved with Tfs/(Ar) and Tcs/(Ar), shown in Table 31.3, has significant importance in the practical application of the plasma technique without any of the potentially deleterious effects of fluorine-based systems. Argon plasma treatments on both flow system TMS (Tfs) and closed system TMS (Tcs) polymers were then investigated as an additional system modification that could provide strong adhesion without the incorporation of fluorine-containing monomers in the quest to produce chromate-free coatings systems. 

Fluorine contamination has been reported in various environments and applications in the past. It has shown up in plasma processing [10-18], as crosscontamination from storage in contaminated containers or with contaminated samples [14,18], and modification of aluminum deposited on fluoropolymer substrates and other polymers having fluorine-based plasma treatments has also been observed [19-21]. Fluorocarbon lubricants have also been noted to modify the oxide structures on aluminum alloys [22,23], and the degradation of AI2O3 catalytic supports has been associated with fluoride conversion during reactions with fluorocarbons [24]. Alloy oxide modification has also been well noted in the presence of fluorine compounds not of the fluorocarbon family [25]. 

The present investigation describes the successful modification of the surface properties of polymeric solids by the adsorption of appropriate partially fluorinated compounds at polymer-air interfaces during the formation of the polymer surfaces. The extent of additive adsorption was foxmd to be dependent upon the molecular structure, fluorine content, and solubility of the additives in the solute—i.e., their organophilic-organophobic balance with respect to the solute. Certain effective additives were able to decrease the critical surface tension, of such polymers as poly(methyl methacrylate) and polyacrylamide to 20 and 11 dynes per cm., respectively. These low values correspond to surfaces containing closely packed CF2 and CF3 groups. 

Apart from PLA-based polymers, amphiphilic polymers containing fluorinated blocks are also favorable materials for biomedical applications. Due to their antifouling properties, fluorinated polymers are feasible materials for coatings in biomaterials science. However, their inert nature hampers chemical modification for the development of novel materials. In order to alter the properties of fiuorinated polymers, rather harsh conditions have to be employed. 

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