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Infrared and nuclear magnetic resonance (NMR) spectroscopies have been applied for quantitative comparison on unsaturated bonds in tetrafluoroethylene (TFE)-propylene (P)-vinylidene fluoride (VdF) terpolymers. These spectroscopies have led to consistent results while they are based on completely different principles. It is shown that the absolute concentration can be evaluated from NMR measurements. The behavior of unsaturation has been discussed in terms of after-treatment such as wet and dry treatments. The result obtained here can give the important information to improve the performance of fluoroelastomer based on TFE-P-VdF terpolymers. 相似文献
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Takuji Ishikawa Tesuhiro Kodani Tsukasa Moriya Minoru Toriumi Hirokazu Aoyama Takamitsu Furukawa Kiyoshi Fujii 《Journal of fluorine chemistry》2004,125(11):1791-1799
We have synthesized various main-chain fluorinated polymers and studied base-resin properties, such as transparency at 157 nm, solubility in a standard alkaline developer, and lithographic performance. Main-chain-fluorinated polymers were synthesized by copolymerization of tetrafluoroethylene (TFE) with cyclic monomers, especially newly synthesized norbornene derivatives. We studied the correlation between pKa(OH) and the solubility of the copolymers of TFE and functional (fluoroalkyl alcohol group) norbornenes. Their solubility depends on the pKa value of the fluoroalkyl alcohol groups.We studied the impact of the polymerization initiators on base-resin properties. High transparency was obtained by using the fluorocarbon initiator. It was also confirmed that the monocyclic component improves dry-etch resistance and that fluorination at the terminal groups improves alkaline solubility.In addition, we found that the development characteristics of TFE/norbornene copolymers were significantly improved by the stereoselective (endo versus exo) partial protection of the hydroxyl groups in the fluoroalkyl alcohol moiety attached to norbornene unit. The polymer protected only in the exo position of the norbornene unit in the copolymer had a higher Rmax and a higher contrast. Positive-working resists based on these fluoropolymers were developed and 55 nm dense lines could be delineated by exposure at 157 nm wavelength with an alternating phase shift mask on a 0.9 NA 157 nm exposure tool. 相似文献
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Carrier mediated telomerization (CMT) between C2F4 and bromochlorofluoroethanes has been evaluated in terms of product distributions arising from CMT and ‘normal’ telomerization. The effect of parameters like type of initiator and telogen, TFE pressure and temperature on the reaction has been studied. The peroxide initiated telomerization between dibromohaloethanes and C2F4 offers an easy synthetic route to α,ω-dibromo perfluoroalkanes Br(CF2)nBr with n = 2, 4, 6 and 8. The selectivity of the CMT products versus those from “normal” telomerization depends mainly on the choice of telogen and on its ability to act as ‘bromine donor’ in the radical telomerization. These perfluoroalkyl dibromides are useful intermediates for other derivatives, for example, perfluorinated mono- and diolefins, Br(CF2)nCHCH2 and CH2CH(CF2)nCHCH2. 相似文献
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Sadulla R. Allayarov Tatyana A. Konovalova A. Ligia Focsan Raluca Craciun Joseph S. Thrasher 《Journal of fluorine chemistry》2006,127(10):1294-1301
The direct fluorination of polyvinylidenefluoride (PVDF) and the copolymer of tetrafluoroethylene with ethylene (CTE) was studied at 35-300 K. The dependence of radical formation on temperature and reaction time was obtained by use of electron paramagnetic resonance (EPR) spectroscopy. Primary alkyl radicals formed as a result of the reaction of fluorine abstracting a hydrogen from the polymer were detected at 35 K. These radicals rapidly react with molecular oxygen producing long-lived (∼48 h at 300 K) peroxy radicals. The peroxy radicals when subjected to UV-irradiation (λ < 280 nm) give rise to other radicals that are not stable at T > 77 K. The concentration of the radicals produced during fluorination of PVDF at 77-200 K is one order of magnitude less than that formed from CTE under similar conditions. A mechanism based on the abstraction of the H and the energies of the C-H bonds is given. Density functional theory was used to predict the structures and EPR parameters for a number of fluorinated radicals to explain the observed spectra. The FOO radical was detected at low temperatures. 相似文献
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The reductive dimerization of dithianylium ions, followed by oxidative fluorodesulfuration, opens a convenient access to a variety of 1,2-disubstituted tetrafluoroethylene derivatives. A similar method leads to hexafluorodiacetyl, a potential building block for fluorinated heterocycles. 相似文献
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Yurii L. Yagupolskii 《Journal of fluorine chemistry》2005,126(4):667-670
Alkylation of N-(1,1,2,2-tetrafluoroethyl)imidazole (1) by alkyl iodides and metathesis resulting in corresponding tetrafluoroborates and bis(trifluoromethanesulfonyl)amides led to the formation of new type stable ambient temperature ionic liquids 3 and 4 with a difluoromethylene fragment directly bonded to the nitrogen atom. 相似文献
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采用火焰喷涂技术制备了乙烯-四氟乙烯共聚物(ETFE)涂层。利用红外光谱仪(FTIR)、差示扫描量热仪(DSC) 及摩擦磨损试验机考察了涂层的结构、热性能及摩擦学性能,并采用扫描电子显微镜(SEM)对涂层的磨损表面形貌进行分析。结果表明: ETFE粉末在火焰喷涂过程中没有发生氧化、降解反应;在摩擦载荷为20~120 N及摩擦速度为20~120 r/min的干摩擦条件下,涂层的摩擦系数为0.25~0.34,磨损量为0.006 8~0.157 8 g/(N?m);SEM分析表明涂层的磨损机制主要为塑性变形、疲劳磨损和轻微的黏着磨损。 相似文献
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A.E. Feiring M.K. Crawford W.B. Farnham J. Feldman R.H. French K.W. Leffew V.A. Petrov F.L. Schadt III R.C. Wheland F.C. Zumsteg 《Journal of fluorine chemistry》2003,122(1):11-16
Photolithography at 157 nm requires development of new photoresists that are highly transparent at this wavelength. Transparent fluoropolymer platforms have been identified which also possess other materials properties required for chemically amplified imaging and aqueous development. Polymers of tetrafluoroethylene (TFE), a fluoroalcohol-substituted norbornene and an acid-labile acrylate ester show the best combination of properties. A solution, semibatch, free-radical polymerization process was developed allowing synthesis of the terpolymers on a multikilogram scale. Further property enhancements may arise from replacing the norbornene with functionalized tricyclononenes. Formulated resists have been imaged in a 157 nm microstepper. 相似文献
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