ИСТИНА

Reversible addition-fragmentation chain-transfer (RAFT) polymerization of 2,3,4,5,6-pentaflurostyrene (PFS), and two methacrylic monomers - 2-hydroxypropyl methacrylate (HPMA) and 2-hydroxyethyl methacrylate (HEMA), in the presence of three chain transfer agents: 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (CTA1), 4-сyano-4-(phenylcarbonothioylthio)pentanoic acid (CTA2) and 2-cyano-2-propyl-dithiobenzoate (CTA3) was studied. To find the optimal conditions of synthesis of macroCTAs with different molar weights (chain lengths) we have varied the type of CTA, the [CTA]/[AIBN] molar ratio and reaction time. The living radical polymerization resulted in controlled molecular weights Mn and narrow polydispersity indices Mw/Mn of 1.1-1.3. The activity of CTAs was changed in order CTA2>CTA3>CTA1. The method of synthesis of fluorine-containing diblock-copolymers (DC) by RAFT polymerization of PFS in the presence of PHPMA and PHEMA as macroCTAs, and AIBN as initiator was developed. The narrow and broad molecular weight distributions DC with different composition and molecular weight were obtained. The morphology of the films prepared with slow evaporation of 5 wt % solutions of the copolymers in toluene, followed by annealing under vacuum was studied by transmission electron microscopy. It was shown that DC containing 44 mol % of PPFS adopt spherical morphology. We have observed 40 nm spherical nanodomains dispersed in the PHEMA matrix. At increasing of PPFS content to 57 mol % the elongated spherical nanodomains (L = 70 nm,  40 nm) were obtained. The observed microphase separation with the formation of spherical nanodomains is not typical for DC a composition close to equimolecular one and is probably associated with the formation of hydrogen bonds between the hydroxyl and carbonyl groups (OH ∙∙∙ OH and C = O ∙∙∙ HO) in poly-2-hydroxyethyl methacrylate blocks. Repellent properties of polymers films surface were studied by the wetting method. Installed repellent properties of DC of different composition are determined by the morphology of the films. It was found that films having spherical morphology possess the best repelling properties.