Fluorine-containing Alternating Copolymers

Koyama, Riichi; Satokawa, Takaomi

doi:10.5059/yukigoseikyokaishi.31.518

Cited by 6 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The value of I. 7 57 gem-3 as E-TFE crystal density and 1.684 gem- 3 as amorphous density by the data from Tanigami et al 7 were used to determine the sample crystallinity. The density measured by density column was I.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Melting of Ethylene–Tetrafluoroethylene Copolymer

Nakafuku

Takaoka

Katsura

1999

Polym J

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

“…The ethylene content of the sample was 46.3 mol% by the melting temperature method after Modena. 2 According to the infrared absorption method, 3 the ethylene content was 4 7 mol%.…”

Section: Methodsmentioning

confidence: 99%

Melting of Ethylene–Tetrafluoroethylene Copolymer

Nakafuku

Takaoka

Katsura

1999

Polym J

View full text Add to dashboard Cite

“…In contrast to the g-t-t conformer, the introduction of a gauche conformation to 2 , resulting in a t-g-t conformer, causes lower frequency shifts for all fluorines [ Fig. 6(c)].…”

Section: Origin Of High-frequency Shiftsmentioning

confidence: 99%

“…Although these polymers exhibit similar properties with respect to densities, refractive indices, tensile strengths and radiation resistance, the melting temperature T m of highly alternating ETFE (305-315°C) is ca 140°C higher than that of PVDF. 2 Even commercial ETFEs containing a small amount of additional monomer exhibit T m ranging from 220 to 270°C. In addition, the glass transition temperature T g of ETFE (90-100°C) is also much higher than that of PVDF (ca 40°C).…”

Section: Introductionmentioning

confidence: 99%

Conformation analysis and molecular mobility of ethylene and tetrafluoroethylene copolymer using solid‐state ¹⁹F MAS and ¹H → ¹⁹F CP/MAS NMR spectroscopy

Aimi

Ando

2004

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

The changes in the conformation and molecular mobility accompanied by a phase transition in the crystalline domain were analyzed for ethylene (E) and tetrafluoroethylene (TFE) copolymer, ETFE, using variable-temperature (VT) solid-state 19F magic angle spinning (MAS) and 1H --> 19F cross-polarization (CP)/MAS NMR spectroscopy. The shifts of the signals for fluorines in TFE units to higher frequency and the continuing decrease and increase in the T1rho(F) values suggest that conformational exchange motions exist in the crystalline domain between 42 and 145 degrees C. Quantum chemical calculations of magnetic shielding constants showed that the high-frequency shift of TFE units should be induced by trans to gauche conformational changes at the CH2-CF2 linkage in the E-TFE unit. Although the 19F signals of the crystalline domain are substantially overlapped with those of the amorphous domain at ambient probe temperature (68 degrees C), they were successfully distinguished by using the dipolar filter and spin-lock pulse sequences at 145 degrees C. The dipolar coupling constants for the crystalline domain, which can be estimated by fitting the dipolar oscillation behaviors in the 1H --> 19F CP curve, showed a significant decrease with increasing temperature from 42 to 145 degrees C. This is due to the averaging of 1H-19F dipolar interactions originating from the molecular motion in the crystalline domain. The increase in molecular mobility in the crystalline domain was clearly shown by VT T1rho(F) and 1H --> 19F CP measurements in the phase transition temperature range.

show abstract