• Polymer(Korea)
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• v.32 no.4
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• pp.385-389
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• 2008

Chain propagation and chain transfer in anionic polymerization of hexafluoropropylene oxide were investigated under various reaction conditions such as the stabilization of reaction temperature, the amount of hexafluoropropylene solvent, and the feeding rate of hexafluoropropylene oxide monomer. Anionic initiator for the polymerization was synthesized from cesium fluoride and hexafluoropropylene oxide in tetraethyleneglycol dimethylether. It was possible to obtain a high molecular weight poly(HFPO) ($M_w$ 14800) using the anionic initiator in conditions of stabilized reaction temperature, and optimized addition of solvent and monomer feeding (HFP/initiator mole ratio=31.5 and HFPO feeding rate=11.67 g/hr). Otherwise, chain transfer reaction in anionic polymerization was increased. From the results of molecular weight in various reaction conditions, it was found that chain propagation and chain transfer in anionic polymerization of HFPO were very sensitive to reaction conditions.

• Polymer(Korea)
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• v.37 no.1
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• pp.80-85
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• 2013

Anionic polymerization of hexafluoropropylene oxide (HFPO) was investigated under various reaction conditions such as various hexafluoropropylene (HFP) oligomers composed of dimer and trimer, reaction temperatures, and feeding rates of hexafluoropropylene oxide monomer. HFP oligomer was synthesized from cesium fluoride (CsF) and HFP in tetraethyleneglycol dimethylether (TG). Under 5 g of CsF, 200 g of HFP, 10 g of TG, and reaction temperature $30^{\circ}C$, HFP dimer content in oligomer was relatively increased. HFPO oligomer with a high molecular weight ($M_w$ 3600) was synthesized in conditions of reaction temperature $0^{\circ}C$, HFP oligomer with 35.1% of dimer, and 1.85 g/min of HFPO feeding rate. Otherwise, chain transfer was increased under unoptimized reaction conditions. Consequently, it was found that reaction conditions impact chain propagation and chain transfer in the anionic polymerization of HFPO.

• Polymer(Korea)
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• v.35 no.2
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• pp.166-170
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• 2011

This study reported the synthesis of perfluoropolyether intermediate (TP-$COOCF_3$) having a $CF_3$ functional group via electrophilic fluorine substituting direct fluorination from PFPE intermediate (TP-$COOCH_3$) having a $CH_3$ functional group, which was synthesized by the ring opening polymerization and methyl esterification of HFPO. The effects of reaction conditions such as the amount of solvent, fluorine partial pressure, reaction time, were investigated. The results showed that the yield of fluorination reaction became the highest when the reaction was carried out in a mild condition for a long reaction time, which also minimized side reactions. The sample was characterized by FTIR and NMR, which confirmed the synthesis of the final product, TP-$COOCF_3$, via direct fluorination converting $CH_3$ of TP-$COOCH_3$ to $CF_3$ of TP-$COOCF_3$ with 95.4% yield.