Trifluorovinyl Ether Groups Research Articles

Partially Bio-Based and fluorinated polysiloxane with high transparency and low dielectric constant

Bio-based polymers with unique properties have attracted much more attention nowadays because of the increasing sustainable development aspirations. In this study, bio-based siloxane precursors functionalized with multiple trifluorovinyl-ether (TFVE) groups were successfully synthesized through facile derivation from renewable eugenol. Firstly, eugenol was converted into a TFVE-functionalized monomer (1). Then, hydrosilylations between monomer 1 and commercially available hydrosiloxanes were performed to prepare fluorinated siloxanes with various functionalities. Polymerization steps were realized to prepare fluorinated linear M−PFCB and crosslinked D4-PFCB connected by perfluorocyclobutyl (PFCB) groups via the [2π+2π] thermal addition between TFVE groups, which occurred through an environment-friendly process without any catalysts or solvents. Due to the coexistence of siloxane segments and PFCB linkers, both polysiloxanes exhibited excellent transparency. In particular, the crosslinked D4-PFCB showed good thermostability with a 5 wt% loss temperature of 403 °C. Furthermore, presence of PFCB segments in D4-PFCB also resulted in the high hydrophobicity and low dielectric constant. Especially, D4-PFCB exhibited a low dielectric constant of 2.60 at 12 GHz, indicating its potential application in the encapsulation fields.

Resveratrol-Based Fluorinated Materials with High Thermostability and Good Dielectric Properties at High Frequency

Two resveratrol-based monomers with thermo-cross-linkable trifluorovinyl-ether groups (−OCF═CF2) have been designed and synthesized. After treating at a temperature above 140 °C, the monomers were ...

Study on the Synthesis and Thermal Stability of Silicone Resin Containing Trifluorovinyl Ether Groups.

Silicone resin is a high-temperature resistant material with excellent performance. The improvement of its thermal stability has always been the pursuit of researchers. In this paper, a sequence of silicone resins containing trifluorovinyl ether groups were prepared by the co-hydrolysis-polycondensation of methyl alkoxysilane monomers and {4-[trifluorovinyl(oxygen)]phenyl}methyldiethoxysilane. The structures of the silicone resins were characterized by FT-IR and 1H NMR. The curing process of them was studied by DSC and FT-IR spectra, and results showed that the curing of the resins included the condensation of the Si-OH groups and the [2 + 2] cyclodimerization reaction of the TFVE groups, which converted to perfluorocyclobutane structure after curing. The thermal stability and thermal degradation behavior of them was studied by TGA and FT-IR spectra. Compared with the pure methyl silicone resin, silicone resins containing TFVE groups showed better thermal stability under both N2 and air atmosphere. Their hydrophobic properties were characterized by contact angle test. Results showed that PFCB structure also improved the hydrophobicity of the silicone resin.

A New Four‐Arm Organosiloxane with Thermopolymerizable Trifluorovinyl ether Groups: Synthesis and Conversion to the Polymer with both Low Dielectric Constant and Low Water Uptake

A new fluoro‐containing four‐arm organosiloxane has been successfully synthesized, which can be easily converted to a cross‐linked network, showing water uptake of below 0.12 wt% (maintained in boiling water for 72 h) and dielectric constant of below 2.56 with dissipation factor of near 1.8 × 10−3 at 30 MHz, as well as showing high transparency and good thermostability. These data indicate that this new organosiloxane is suitable as an adhesive or sealant for the applications in microelectronic industry. image

Fluorinated and Thermo-Cross-Linked Polyhedral Oligomeric Silsesquioxanes: New Organic-Inorganic Hybrid Materials for High-Performance Dielectric Application.

A fluorinated and thermo-cross-linked polyhedral oligomeric silsesquioxane (POSS) has been successfully synthesized by thermal polymerization of a fluorinated POSS monomer having an inorganic silsesquioxane core and organic side chains bearing thermo-cross-linkable trifluorovinyl ether groups. This new inorganic-organic hybrid polymer shows high thermostability with a 5 wt % loss temperature of 436 °C, as well as good transparency (a sheet with an average thickness of 1.5 mm shows high transmittance of 92% varying from 400 to 1100 nm). Moreover, the polymer exhibits both low dielectric constant (<2.56) and low dissipation factor (<3.1 × 10-3) in a wide range of frequencies from 40 Hz to 30 MHz even at a high frequency of 5 GHz. The polymer also shows low water uptake (<0.04%) and low Dk (near 2.63) after immersing it in water at room temperature for 3 days. These data imply that this polymer is very suitable to be utilized as a high-performance dielectric material for fabrication of high-frequency printed circuit boards or encapsulation resins for integrated circuit dies in the microelectronic industry. Furthermore, this work also provides a route for the preparation of fluorinated POSS-based polymers.

An Intrinsically Microporous Network Polymer with Good Dielectric Properties at High Frequency

An intrinsically microporous fluoropolymer has been successfully synthesized through thermo-cross-linking of a functional monomer having a quaternary carbon center and thermopolymerizable trifluorovinyl ether groups as the side chains. Because the monomer has a tetrahedral configuration, the thermo-cross-linking produces spontaneously formed micropores with an average size of 8 A in the polymer. Because of the existence of the micropores, the fluoropolymer exhibits excellent dielectric properties with dielectric constant (Dk) of 2.36 and dissipation factor (Df) of 1.29 × 10–3 at a frequency of 5 GHz. Moreover, the polymer shows very low water uptake (<0.08% in water of 99 °C for 72 h) and high transparency (transmittance of 93% varying from 400 to 1100 nm). TGA and DMA data show that the polymer has 5 wt % loss temperature of 492 °C (in N2) and Young’s modulus of 4.95 GPa, respectively. These results suggest that the polymer is very suitable as the matrix resin for the production of the composites utilize...

Facile method towards functionalization of partially fluorinated polyarylethers via sequential post-polymerization modification

A novel partially fluorinated arylene vinylene ether (FAVE) polymer containing ester groups was synthesized, which was used to prepare three reactive FAVE polymers containing carboxylic acid groups, alcohol groups, and acid chloride groups, respectively. Post-polymerization modifications of the FAVE polymer's carboxylic acid groups (via a DCC coupling procedure with the desired alcohol), alcohol groups (via DCC coupling or an acid chloride esterification procedure with the desired carboxylic acid or acid chloride), and acid chloride groups (via an optimized nucleophilic substitution reaction with the desired alcohol or amine) were successfully performed. Several examples have been successfully prepared to demonstrate the versatility of these developed modification methods. FAVE polymers have been prepared with NHS active ester groups, Disperse Red 1 chromophores, benzyl bromide groups, aryl trifluorovinyl ether groups, ATRP initiator groups, vinyl groups, propargyl groups, Disperse Orange 3 chromophores, and benzaldehyde groups. In most cases, analytical data are consistent with a quantitative conversion of the reactive or functional groups. It is demonstrated that no degradation of the FAVE polymer matrix occurs after multistep post-polymerization modification reactions.

Postpolymerization of Functional Organosiloxanes: An Efficient Strategy for Preparation of Low-k Material with Enhanced Thermostability and Mechanical Properties

A novel functional oligomer (Si-TFVE) with a siloxane backbone and thermally cross-linkable trifluorovinyl ether groups (−OCF═CF2) is reported here. When postpolymerized at high temperature, Si-TFVE converts to an amorphous cross-linked network (Si-PFCB), which shows a dielectric constant of 2.33 and dielectric loss below 2.1 × 10–3 at 30 MHz. Si-PFCB also shows excellent film uniformity with the surface roughness less than 5.79 nm over a 1 μm square area. Moreover, Si-PFCB shows high thermostability with a 5 wt % loss temperature of 472 °C and no obvious Tg below 350 °C. In regard to the mechanical properties, Si-PFCB has Young’s modulus, hardness, and bonding strength with silicon wafer surface of 10.06 GPa, 0.392, and 4.93 GPa, respectively. These results suggest that such oligomer is suitable for utilization in ultralarge scale integration circuits. In addition, this contribution provides a new route to prepare cross-linked organosiloxanes only by heating instead of using catalysts or initiators in th...

Crosslinked monosulfonated poly(arylene ether) using cyclodimerization of trifluorovinyl ether groups for fuel cell applications

AbstractA crosslinker and crosslinkable sulfonated poly(arylene ether)s with trifluorovinyl ether groups were synthesized via reaction of 4‐trifluorovinyloxyphenol for application in fuel cells. Crosslinked poly(arylene ether) membranes were prepared by thermal irradiation, and the cyclodimerization of the trifluorovinyl ether groups in the polymers as well as the crosslinker was confirmed using differential scanning calorimetry and infrared measurements. These crosslinked membranes showed a low swelling ratio, comparable to that of Nafion 112. The proton conductivity of the crosslinked membranes was 0.17 and 0.3 S cm−1 at 30 and 80 °C, respectively, much higher than that of Nafion 112 under the same conditions. The excellent dimensional stability and high conductivity of the crosslinked membranes can be attributed to this new type of crosslinking system (end‐group crosslinking) as well as the chemical structure of crosslinked (multi‐block) polymers. Copyright © 2011 Society of Chemical Industry

Hole mobilities of thermally polymerized triaryldiamine derivatives and their application as hole-transport materials in organic light-emitting diodes (OLEDs)

This paper describes the synthesis of three triaryldiamine derivatives presenting two thermally polymerizable trifluorovinyl ether groups that can be polymerized through thermal curing to form perfluorocyclobutyl (PFCB) polymers. These PFCB polymers, studied using time-of-flight techniques for the first time, exhibited remarkable non-dispersive hole-transport properties, with values of μ h of ca. 10 −4 cm 2 V −1 s −1. When we employed these thermally polymerized polymers as hole-transport layers (HTLs) in electroluminescence devices containing tris(8-hydroxyquinolate) aluminum (Alq 3) as the emission layer, we obtained high current densities (ca. 3400 mA cm −2), impressive brightnesses (5 × 10 4 cd m −2), and high external quantum efficiencies (EQEs = 1.43%). These devices exhibited the same turn-on voltage, but higher EQEs, relative to those incorporating the vacuum-processed model compound N, N′-di(1-naphthyl)- N, N′-diphenylbenzidine (α-NPD) (EQE = 1.37%) as the HTL under the same device structure.

Synthesis and polymerization of trifluorovinylether-terminated imide oligomers. I

The objective of this research was the preparation of imide trimers, terminated with trifluorovinyl ether groups, that could be melt processed and then polymerized to high molecular weight via the thermal dimerization of the trifluorovinyl ether moieties. The work was begun with the synthesis of an aromatic amine end-capping agent containing trifluorovinyl ether functionality, i.e. 4-(trifluorovinyloxy)aniline (TFVA). Melt-processable imide trimers were prepared from the end-capping agent and 2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BisA-DA) and 2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA). The trimers underwent thermal cyclopolymerization to afford polyimides containing perfluorocyclobutane (PFCB) rings. The DSC thermogram of the imide trimer prepared from TFVA and BisA-DA contained a melting endotherm with a minimum of 153°C and a polymerization exotherm with a maximum at 220°C. The thermogram of the trimer prepared from TFVA and 6FDA had a melting endotherm with a minimum at 136°C and a polymerization exotherm with a maximum at 244°C. The PFCB-containing polyimides obtained from the melt polymerizations had intrinsic viscosities of 0.63 and 0.31dl/g, respectively. The TFVA/BisA-DA polymer had a Tg of 186°C, while the Tg of the TFVA/6FDA polyimide was 206°C. The coefficient of thermal expansion of a thin film of the TFVA/BisA-DA polyimide was 57.1×10−6(°C)−1. The film displayed a tensile strength of 88MPa, a modulus of 2113MPa, and elongation at break of 6.5%. The water absorption of this polyimide was 0.08%.

A new synthetic approach to poly- and perfluorinated polyethers

Linear and cyclic perfluorinated polyethers are prepared by a new route involving polymerization of a trifluorovinyl ether alcohol (CF 2 =CFOR f CH 2 OH (1), R f =CF 2 CF(CF 3 )OCF 2 CF 2 ) followed by fluorination of the intermediate polyfluorinated polyethers. Polymerization occurs by ionic addition of OH groups to trifluorovinyl ether groups. In the absence of solvent, linear polymers with M n values up to 29000 are obtained in excellent yield. In glyme solution, cyclic oligomers are the major products and a cyclic dimer is obtained in yields as high as 60%