Copolymerization of 2,2,3,3,4,4,4-heptafluorobutyl acrylate with butyl acrylate via RAFT polymerization

• Copolymerization of a fluorinated butylacrylate (HFBA) and butyl acrylate (BA) was carried out via RAFT polymerization.
• The reactivity ratio of BA was higher than that of HFBA, as determined by different models.
• Thermal stability, Tg as well as hydrohobicity of the copolymers increased with increase in HFBA content.

Copolymers of fluoroacrylates have interesting properties like excellent resistance to chemicals, oils and fuels, high thermal stability and high hydrophobicity. This investigation reports the copolymerization of 2,2,3,3,4,4,4-heptafluorobutyl acrylate (HFBA) and butyl acrylate (BA), i.e. the two monomers having semi-fluorinated and non-fluorinated pendant groups of equal length (C4) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The copolymers had controlled molecular weights and narrow polydispersity indices. The copolymer compositions were determined by 1H NMR spectroscopy. The reactivity ratios of HFBA and butyl acrylate BA were calculated by using three different models viz., Finemann–Ross (FR), inverted Finemann–Ross (IFR) and Kelen–Tudos (KT). The reactivity ratios were determined as rHFBA = 0.65 and rBA = 0.83, by the FR method. Thermal stability and glass transition temperature of the copolymers increased with the increase in HFBA content. The water contact angle (WCA) of the copolymers increased with increase in HFBA content indicating increasing hydrophobicity of the copolymer having higher HFBA content.

This manuscript describes the copolymerization of 2,2,3,3,4,4,4-heptafluorobutyl acrylate (HFBA) with butyl acrylate (BA) via RAFT polymerization using 4-cyanopentanoic acid dithiobenzoate (CPDTB) as chain transfer agent (CTA) in 1,4-dioxane. The reactivity ratios of comonomers were determined using three different models. Effects of HFBA on the thermal stability, glass transition temperature and wetting property of the copolymers have also been studied.Figure optionsDownload as PowerPoint slide