| 초록 |
The well-defined α,ω-diiodo-poly[vinylidene fluoride(VDF)-co-hexafluoropropylene(HFP)] with narrow unimodal molecular weight distribution(PDI=1.05-1.3) was polymerized by Iodine Transfer Polymerization(ITP), which are one of the controlled "Pseudo-living" free-radical telomerization methods. The chain-end structure of α,ω-diiodo-poly(VDF-co-HFP) was consisted of both -CH2CF2-I and -CF2CH2-I. The high iodine-functionality was obtained at the low [monomer]/[iodine compd.]. HFP contents in these copolymer(10∼30mol%) could be controlled by changing monomer feed ratio. These α,ω-diiodo-poly(VDF-co-HFP) were converted to α,ω-bis(hydroxyethyl)-poly(VDF-co-HFP) after the addition of one ethylene unit, followed by the hydrolysis using water, and bicarbonate anion as a nucleophile as well as a phase-transfer reagents in polar aprotic solvent(HMPA). The structure and functionality of these dihydroxy fluoro polymers were characterized by 1H-NMR, 13C-NMR, 19F-NMR and end-group titration and showed high conversion. As these fluorocopolymers with the molecular weight below 4,000g/mol were expected to exhibit wide spectrum of their unique properties, these can be used as telechelic fluorinated prepolymer for the modification of polyurethanes or others with low surface energy, good chemical and thermal stability. |
