Figure 4 - uploaded by Jianfu Ding
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1 H (top) and 19 F (bottom) NMR spectra of the sample extracted using hexane from the final solution (400 min) of the reaction between DFBP (1.0 equiv) with 6C F-diol (2.5 equiv) in DMAc using CsF as a base.
Source publication
A series of highly fluorinated poly(arylene alkylene ether)s, P6CFXs (X ) Non, S, K, SO, Ox) have been prepared by polycondensation reactions of 1H,1H,6H,6H,-perfluorohexane-1,6-diol (6CF-diol) with a series of decafluorodiphenyl compounds (DFPXs) including decafluorobiphenyl (DFP), decafluorodiphenyl sulfide (DFPS), decafluorobenzophenone (DFPK),...
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Context 1
... verify this assumption, the final solution of this reaction was extracted with hexanes in order to separate the free molecules, and the extracted material was found to be a mixture of compounds II and III by 1 H and 19 F NMR analysis. The resonances assigned in Figure 4 use the structures shown in Scheme 2. Therefore, we can conclude that the sharp peaks in the spectrum of the 400 min sample in Figure 3 and the peaks indicated with stars in Figure 2 are due to the formation of tetrafluorobenzene moieties, resulting from the ketone cleavage. It should be noted that the solution for collecting spectra in Figure 2 contains small amounts of DMAc from the reaction solution, while the solution for Figure 4 does not. ...
Context 2
... resonances assigned in Figure 4 use the structures shown in Scheme 2. Therefore, we can conclude that the sharp peaks in the spectrum of the 400 min sample in Figure 3 and the peaks indicated with stars in Figure 2 are due to the formation of tetrafluorobenzene moieties, resulting from the ketone cleavage. It should be noted that the solution for collecting spectra in Figure 2 contains small amounts of DMAc from the reaction solution, while the solution for Figure 4 does not. This causes slight differences in the chemical shifts of certain peaks between Figures 2 and 4. ...
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A new monomer, 2,6-difluorophenyl-(4′-perfluorononenyloxy)phenyl-methanone (2F-PFN), was synthesized using a simple two-step reaction. A series of novel poly(ether ether ketone)s (PEEK-PFN-x) containing perfluorononenyl groups were then prepared from 2F-PFN, resorcin, and 4,4′-difluorobenzophenone by nucleophilic polycondensation. The resulting cop...
Citations
... 25 Additionally, the high fluorine content in conjunction with aromaticity imparted to polymers derived from PFAr's endows these materials with exceptional thermal stability and processability. 26,27 Of the many PFAr's, perfluoropyridine (PFP) has proven to be an auspicious scaffold for fluoropolymer design, owing to its predictable and discrete regio-selective substitution pattern at the 2-, 4-, and 6-positions on the ring, its predilection for chemo-selective nucleophilic aromatic substitution, and its wide scope of nucleophile permissibility. 28−31 These properties permit facile incorporation of PFP into novel polymer architectures, allowing for diverse and tailorable material properties. ...
High-temperature linear fluoropyridyl silicone-based oils and network elastomers were prepared via hydrosilylation with multifunctional perfluoropyridine (PFP)-based monomers possessing terminally reactive alkenes. Monomers with varying degrees of functionalization were prepared in a scalable manner and in high purity via the facile, regio-selective, nucleophilic aromatic substitution (SNAr) of PFP in good isolated yields. These multi-reactive monomers were polymerized via Pt-catalyzed hydrosilylation with hydride-terminated polydimethylsiloxanes (H-PDMSs) possessing varying degrees of polymerization and cross-linked with the highly functionalized octadimethylhydrosilyl cubic siloxane. These resulting polymers of varying architecture possessed exceptional thermal stability with no onset of degradation up to 430 °C and char yields as high as 62%, under inert pyrolysis conditions when modified with cubic siloxane. Furthermore, by nature of the aliphatic or aromatic content, programmable glass transition temperatures were achieved from these elastomeric materials. Finally, the linear 3,5,6-fluoropyridine PDMS systems demonstrated the ability to undergo regio-controlled post-functionalization via SNAr with 4-bromophenol, allowing access to silicone oils with potentially tailorable properties for desired applications. © Not subject to U.S.
... F luorinated materials exhibit many highly desirable properties such as increased chemical resistance, hydrophobicity, and thermal stability. One common route to introduce fluorine into polymer backbones is through the polycondensation of perfluoroarene-containing monomers ( Fig. 1) [1][2][3][4][5][6][7][8][9][10][11][12] . These perfluorinated aromatic polymers impart increased order and stability to processed materials by forming energetically favorable π-π stacking arrangements with non-perfluoroarenes 13,14 , as evidenced by their thermal properties 4 . ...
The preparation of high-performance fluorinated poly(aryl thioethers) has received little attention compared to the corresponding poly(aryl ethers), despite the excellent physical properties displayed by many polysulfides. Herein, we report a highly efficient route to fluorinated poly(aryl thioethers) via an organocatalyzed nucleophilic aromatic substitution of silyl-protected dithiols. This approach requires low catalyst loadings, proceeds rapidly at room temperature, and is effective for many different perfluorinated or highly activated aryl monomers. Computational investigations of the reaction mechanism reveal an unexpected, concerted SNAr mechanism, with the organocatalyst playing a critical, dual-activation role in facilitating the process. Not only does this remarkable reactivity enable rapid access to fluorinated poly(aryl thioethers), but also opens new avenues for the processing, fabrication, and functionalization of fluorinated materials with easy removal of the volatile catalyst and TMSF by
... The results indicated that the decafluorobiphenyl and monomer 1 were so reactive that the side reactions, such as branching and crosslinking, occurred in such condition. A modification method was introduced by Ding [34], in which the reactions conducted in milder conditions thereby depressing the side reaction, but special catalyzer must be employed. In our procedure, the reaction was conducted in DMAc in the presence of K 2 CO 3 at 120°C for 4-6 h, high molecular weight polymers (M n = 46,400, M w = 96,300) were obtained. ...
Partially fluorinated poly(fluorenyl ether ketone)s with different degree of sulfonation were successfully synthesized by
the sulfonation of the designed parent polymer. The sulfonation took place only at the specific (2, 7)-position on the fluorenyl
groups due to the positions adjacent to the ether bond occupied by methyl groups. The sulfonated polymers are soluble in common
organic solvents and can readily be cast into tough and smooth films from their solutions. The properties of proton conductivity,
water uptake, thermal and oxidative stability for the membranes were investigated. It was found that the oxidative stability
of the membrane decreased with increasing the degree of sulfonation. However, the partially fluorinated membrane with high
degree of sulfonation exhibited better oxidative stability compared to the non-fluorinated analogy with low degree of sulfonation.
The proton conductivity of the membranes increased with increasing the degree of sulfonation and temperature. Moreover, the
membranes also showed good thermal and hydrolytic stabilities.
KeywordsPoly(ether ketone)s–Fluoropolymers–Proton exchange membranes–Oxidative stability
... 11,12 Among all fluorinated polymers, fluorinated poly(arylene ether)s have been shown to be one of the most promising classes of candidates for optical waveguide devices. [13][14][15][16] Fluorinated poly(arylene ether)s not only have lower near-infrared region absorption but also show higher thermal stability and lower water absorption. However, it is difficult for fluorinated polymers to adhere to many substrates because of their inert natures and low surface energies. ...
A series of novel fluorinated crosslinkable poly(phthalazinone ether)s bearing tetrafluorostyrene groups (FSt-FPPEs) was prepared by polycondensation from 4-(4′-hydroxyphenyl)-phthalazin-1(2 H)-one (DHPZ), decafluorobiphenyl, 4,4-(hexafluoroisopropylidene)diphenol (6F-BPA) and pentafluorostyrene (FSt) for optical waveguide applications. The obtained polymers exhibited good solubility in common organic solvents and could be easily cast into optical-quality thin films. The resulting polymers could be thermally crosslinked either at 160 °C in the presence of a free radical initiator dicumyl peroxide under vacuum or at 280 °C in the absence of any initiator under vacuum. The polymers had high glass transition temperatures in the range 164–269 °C, which could be further increased by about 10 °C on thermal crosslinking. The crosslinked polymers had good thermal stabilities (the temperatures of 1% mass loss after curing ranged from 478 to 490 °C) and high glass transition temperatures. The crosslinked polymer films also exhibited good optical properties. By adjusting the feed ratio of the reactants, the refractive indices of transverse electronic and transverse magnetic modes (at 1550 nm) could be controlled well in the range of 1.4952–1.5625 and 1.4924–1.5538, respectively. The optical losses of the crosslinked polymers were rather low,
... However, the heat of this peak is only about 18% of the main chain homopolymer and the T m is about 32 8C lower (18.3 J Á g À1 , 219 8C for the FPAE homopolymer), [24] indicating the crystallization of the main chain in the copolymer was significantly depressed by the graft structure. ...
A comb copolymer with a fluorinated FPAE main chain and narrowly dispersed PMS graft chains has been prepared. The micellization behavior of this copolymer in a methanol/acetone mixture was studied. DLS studies showed hydrodynamic diameters of the micelles between 50 and 80 nm, while the diameters of dry micelles were ≈40 nm in TEM images. Micelle films with an interesting porous composite structure of nanofibers bearing micelle particles on the surface have been prepared by double coating the micelle solution. Superhydrophobicity with a WCA of 165° and a sliding angle of 3° was observed. As comb copolymers can adjust their molecular weight and block length independently, materials with a high physical strength and controllable morphological structure can be obtained.
magnified image
... Fluorination and deuteration are effective methods to reduce C-H bond overtone absorption because substitution of C-F or C-D for C-H shifts the absorption band to higher wavelength as well as it makes the intensity weak. In the past twenty years, many polymers such as deuterated or fluorinated acrylates [5,6], benzocyclobutenes [7], perfluorocyclobutanes [8], fluorinated dendrimers and hyperbranched polymers [9,10], fluorinated polyimides [11][12][13][14][15], deuterated polyfluoromethacrylates [16], polysiloxanes and inorganic-organic hybrid polymers [17,18], polycarbonates [19][20][21], and fluorinated poly(arylene ether)s [22][23][24][25][26][27][28], have been synthesized for optical passive waveguide application. Among them, fluorinated poly(arylene ether)s are proved to be one of classes of promising candidates due to their low intrinsic absorption at telecommunication wavelengths, good thermal, mechanical and chemical stability [22][23][24][25][26][27][28]. ...
... In the past twenty years, many polymers such as deuterated or fluorinated acrylates [5,6], benzocyclobutenes [7], perfluorocyclobutanes [8], fluorinated dendrimers and hyperbranched polymers [9,10], fluorinated polyimides [11][12][13][14][15], deuterated polyfluoromethacrylates [16], polysiloxanes and inorganic-organic hybrid polymers [17,18], polycarbonates [19][20][21], and fluorinated poly(arylene ether)s [22][23][24][25][26][27][28], have been synthesized for optical passive waveguide application. Among them, fluorinated poly(arylene ether)s are proved to be one of classes of promising candidates due to their low intrinsic absorption at telecommunication wavelengths, good thermal, mechanical and chemical stability [22][23][24][25][26][27][28]. In our previous study, we synthesized a series fluorinated poly(arylene ether)s (FPPEs) containing phthalazinone moieties derived from 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one (DHPZ), decafluorobiphenyl (DFBP) and 4,4 0 -(hexafluoroisopropylidene)diphenol (6F-BPA) by modified nucleophilic polycondensation at lower reaction temperature to suppress the side reaction due to the high reactivity of ortho-fluorine of DFBP [27]. ...
... In optical polymer waveguide materials bearing terminal ethynyl or phenylethynyl groups initially reported [22,23], as the cross-linking reaction occurs only at the polymer chain ends, the theoretical cross-linking density of the cured polymer is limited. Recently research interests focus on introducing cross-linkable groups into polymer chains as internal groups or in the polymer chains [24][25][26]28]. In addition, it is essential that polymer optical materials should have tunable refractive index, since selecting the same kind of polymers to fabricate both the core and the cladding layers is of advantage to a good interface adhesion and comparable thermal expansion coefficients between the two layers. ...
It is necessary to introduce cross-linkable groups onto polymer chains as the processability and thermal stability of the polymers for passive waveguide device applications are very dependent on their cross-linking capabilities. Herein a series of novel cross-linkable allyl-containing fluorinated poly(phthalazinone ether)s (Allyl-FPPEs) have been prepared by a modified polycondensation of 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one (DHPZ), decafluorobiphenyl (DFBP), 4,4'-(hexafluoroisopropylidene)diphenol (6F-BPA), and 3,3'-diallyl-4,4'-dihydroxybiphenyl (DA-DHBP) for optical waveguide applications. The obtained random polymers were characterized by FT-IR, NMR and GPC. The resulting polymers having good solubility in polar organic solvents at room temperature, can be easily spin-coated into thin films with attracting optical quality, good thermal stabilities (the temperatures of 1% mass-loss after curing: 455-503牥C), and high glass transition temperatures (Tgs: 167-251牥C) which could further increase by about 20牥C after thermal cross-linking. The crosslinked polymer films exhibit good optical properties. By adjusting the feed ratio of the reactants, the refractive indices of TE and TM modes (at 1550爊m) could be well controlled in the range of 1.4998-1.5618 and 1.4954-1.5520, respectively. The optical losses of the crosslinked polymers possess rather low values, less than 0.3燿B/cm at 1550爊m.
The rapid development of high-speed communication networks has imposed more stringent requirements on the comprehensive performance of dielectric materials.
Poly(arylene ether)s with different molecular weights were synthesized via a two‐step nucleophilic substitution polymerization by adjusting reaction parameters based on phenolphthalein (PHT) and decafluorobiphenyl (DFBP). The chemical structures and properties were identified by Fourier transform infrared, NMR, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, dynamic thermomechanical analysis (DMA), and so forth. The number‐average molecular weight (Mn) of the resulting polymers was in the range of 23.0–49.3KDa. FPAEs (polyarylether including perfluorobiphenyl structure) were demonstrated to have outstanding thermo‐resistance with 5% weight loss temperature of about 482–520°C (N2) and high‐glass transition temperature (about 240–250°C). FPAEs can be dissolved in conventional organic solvents, possessing excellent film‐forming properties. The good mechanical properties of FPAEs were confirmed by the DMA data, with Young's modulus greater than 1.0 Gpa and modulus retention rate at 230°C >67%. FPAEs also showed good hydrophobicity and low‐water absorption, in particular, FPAE‐1 (FPAE‐1‐5 were the polycondensation products of PHT and DFBP, just the polymerization conditions were slightly modified) exhibited favorable dielectric properties: at 1 MHz, the dielectric constant and dielectric loss was 2.58 and 0.0053, respectively. Thus, FPAE‐1 has broad prospective applications in microelectronic devices and communication technology.
Step-growth polymers and networks were prepared with the nucleophilic aromatic substitution of perfluoropyridine with phenolic substrates. Linear AA-BB type, step-growth polymers were prepared to afford transparent, flexible films that exhibit excellent solution process ability in common organic solvents. Networks of similar type were optimized to produce highly densified crosslinks with moderate thermal stability and exceptional char yields. Herein, we highlight a new methodology and their thermal properties for the preparation of linear and network polymers without the need to pre-install labile moieties producing materials of interest for high performance materials and potential applications thereof.
This report details the properties of fluorine-containing anion exchange membranes(AEMs) synthesized by chloromethylation and quaternization of fluorinated poly(arylene ether)s(FPAEs) based on decafluorobiphenyl and bisphenol A. Meanwhile, we compared their properties with those of their non-fluorinated counterparts, Udel-based AEMs. The reactivity of the chloromethylation of fluorinated poly(arylene ether)s was lowered by the strong electron- withdrawing group, per-fluorinated biphenyl residue. Therefore higher temperature, more chloromethylation reagent, and longer reaction time were needed in the chloromethylation of FPAEs. Because of the hydrophobicity of fluorine, the swelling of FPAEs was depressed. In the FPAE-based AEMs, the water uptake of FPAE-1 membrane(F-1) was just 30%. There is a strong correlation between water uptake and conductivity for both Udel- and FPAE-based AEMs. Among all the membranes, the water uptake and the conductivity of FPAE-3 membrane(F-3) could reach up to 100% and 13.47 mS/cm respectively at 30 °C. The mechanical properties of FPAE-based AEMs at room temperature were worse than those of Udel-based ones because of the weak intermolecular interaction caused by the low polarizability of fluorine. However, their high temperature mechanical properties are better, which can be explained in terms of low swelling.
