Hexafluorobutyl Acrylate Research Articles

Boron removal and antifouling properties of thin‐film nanocomposite membrane incorporating PECVD‐modified titanate nanotubes

AbstractBACKGROUNDIncorporation of nanofillers into the polyamide (PA) layer of thin‐film composite (TFC) membrane could improve membrane surface properties for enhanced water separation efficiency. However, most nanofillers do not disperse well in organic medium. In this work, the surface of titanate nanotubes (TNTs) was modified via the plasma‐enhanced chemical vapour deposition (PECVD) method in order to promote its dispersion rate (in organic medium) during thin‐film nanocomposite (TFN) membrane fabrication.RESULTSFourier transform infrared (FTIR) analysis confirmed the surface chemistry of TNTs coated by hexafluorobutyl acrylate (HFBA) or hydroxyethyl methacrylate (HEMA) via PECVD method. The effects of embedding modified TNTs into the PA layer on membrane surface morphology, hydrophilicity and performance were also investigated and the results were further compared with commercial reverse osmosis (RO) membranes. It was found that the incorporation of HFBA‐ and HEMA‐modified TNTs could enhance the membrane water permeability by >25% and >40%, respectively, without compromising their salt rejection. The boron rejections of TFN membranes incorporated with HFBA‐ and HEMA‐modified TNTs meanwhile were recorded at 75.56% and 70.73%, respectively; these values were relatively higher than those for the self‐synthesized TFC (68.57%) and commercial RO membranes (37–39%). The developed TFN membranes also exhibited higher fouling tolerance than the commercial RO membranes, achieving >94% of water flux regeneration as a result of enhanced membrane surface hydrophilicity.CONCLUSIONCompared to hydrophilic modification using HEMA, nanofillers modified by hydrophobic HFBA proved more effective at producing a PA layer with better nanofiller distribution, making the resultant TFN membrane more suitable for desalination processes. © 2019 Society of Chemical Industry

Nanocrystalline cellulose/fluorinated polyacrylate latex via RAFT‐mediated surfactant‐free emulsion polymerization and its application as waterborne textile finishing agent

ABSTRACTA simple method for nanocrystalline cellulose (NCC)/fluorinated polyacrylate was developed by RAFT‐mediated surfactant‐free emulsion polymerization, in which the nanocomposites formed a core‐shell spherical morphology. The influence of the content of NCC‐g‐(PAA‐b‐PHFBA) (AA was acrylic acid, HFBA was hexafluorobutyl acrylate) on the properties of latex and film were systematically studied. The monomer conversion, the tensile strength, and water–oil repellency of film increased first and then decreased, the latex particle size decreased first and then decreased, when the content of NCC‐g‐(PAA‐b‐PHFBA) increased from 1 to 6 wt %. Elongation at break and thermal stability distinctly decreased when the content of NCC‐g‐(PAA‐b‐PHFBA) gradually increased. XPS showed that the fluorine‐containing groups well concentrated at the film–air interfaces during the annealing process. SEM analysis revealed that the treated fiber had a rugged surface, and the treated fabric had an excellent water repellency. In addition, this green grafting method in water offered a new perspective for the fabrication of exceptional NCC‐based nanocomposites with NCC as the core and also helped to promote the potential applicability of NCC in a range of multipurpose applications. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1305–1314

Improvement of carbon nanotube dispersion in electrospun polyacrylonitrile fiber through plasma surface modification

ABSTRACTIn this study, surfaces of multiwalled carbon nanotubes (CNTs) were functionalized with poly(hexafluorobutyl acrylate) (PHFBA) thin film using a rotating‐bed plasma‐enhanced chemical vapor deposition (PECVD) method without imparting any defects on their surfaces. Polyacrylonitrile (PAN) electrospun polymer fiber mats and composite fiber mats with CNTs and functionalized CNTs (f‐CNTs) were prepared. The wettability and chemical and morphological properties of the synthesized fiber mats were investigated, and the dispersion of CNTs and f‐CNTs in the polymer matrix was compared according to the contact angle results of electrospun polymer mats. According to the chemical and morphological characterization results, PHFBA‐coated CNTs were dispersed more uniformly in the polymer matrix than the uncoated CNTs. The f‐CNTs/PAN composite fiber mat exhibits a lower surface energy than the pristine CNTs/PAN fiber mat. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47768.

Synthesis and Pickering emulsifier performance of Ag/poly((2-dimethylamino)ethyl methacrylate)-co-poly(hexafluorobutyl acrylate) amphiphilic random copolymer hybrid micelles

A new type of comolymer containing nanoparticles, Ag/poly(2-(dimethylamino) ethyl methacrylate-co-hexafluorobutyl acrylate) (Ag/P(DMAEMA-co-HFBA)) amphiphilic random copolymer hybrid micelles was synthesized and used as the high-efficiency particulate emulsifiers to stabilize Pickering emulsion. Firstly, the amphilphilic random P(DMAEMA-co-HFBA) is facilely synthesized by a one-pot radical polymerization of poly(2-(dimethylamino)ethyl methacrylate)(DMAEMA) and hexafluorobutyl acrylate(HFBA). Then, this copolymer self-assembles into spherical-like polymeric micelles, and the effect of the copolymer content on the size and morphology of P(DMAEMA-co-HFBA) micelles was determined by dynamic light scattering(DLS) and transmission electron microscopy(TEM). Then, the Ag/P(DMAEMA-co-HFBA) hybrid micelles were prepared by in suit using P(DMAEMA-co-HFBA) micelles as the nanoreactors. The synthesis mechanism of the Ag/P(DMAEMA-co-HFBA) hybrid micelles was investigated by Fourier transform infrared spectroscopy(FT-IR), X-Ray Diffraction(XRD) and TEM. The hybrid micelles showed surface activity and pH sensitivity for producing Pickering oil-in-water emulsions. The emulsification performance of Ag/P(DMAEMA-co-HFBA) hybrid micelles with different surface activity demonstrated that the Pickering emulsion with long-time stability could only be stabilized by Ag/P(DMAEMA70-co-HFBA30) hybrid micelles, indicating that the surface wettability of Ag/P(DMAEMA-co-HFBA) hybrid micelles plays a crucial role in determining the type and stability of the prepared Pickering emulsions. Additionally, the effect of pH value of the aqueous solution of Ag/P(DMAEMA-co-HFBA) hybrid micelles on the Pickering emulsion were investigated. The Ag/P(DMAEMA70-co-HFBA30) had an excellent emulsification performance at pH value 1.98 and the pH-induced phase inversion derived from obtained emulsions observed at pH higher than 5.15. These results demonstrated that Pickering emulsion could be generated using self-assembled hybrid micelles as the stabilizer, and the prepared Pickering emulsion has promising potential to be applied in the medical and coating industries.

Di-block copolymer stabilized methyl methacrylate based polyHIPEs: Influence of hydrophilic and hydrophobic co-monomers on morphology, wettability and thermal properties

Due to intermediate hydrophobicity of methyl methacrylate (MMA) monomer in water, it is difficult to prepare its stable water in oil high internal phase emulsion (HIPE). Moreover, the addition of fully hydrophilic co-monomer such as 2-hydroxyethyl methacrylate (HEMA) in MMA monomer makes it further troublesome to stabilize these emulsions. This paper addresses the preparation of such type of difficult to prepare emulsions via addition of an amphiphilic fluorinated di-block copolymer (FDB), poly(2-dimethylamino)ethylmethacrylate-b-poly(trifluoroethyl methacrylate) (PDMAEMA-b-PTFEMA) as stabilizer. Interestingly, HEMA and/or HFBA (hexa fluorobutyl acrylate) as co-monomers were successfully added to impart some special properties such as thermodynamic stability, desired amphiphilicity to the final polyHIPEs. Fluorinated blocks in FDB anchored well at oil/water interface of HIPE, offering enough hydrophobicity to the comparatively hydrophilic monomers and in turn providing resistance against coalescence. MMA polyHIPEs were found to be fully hydrophobic just by replacing HEMA co-monomer with HFBA. Due to superb inherent hydrophobic nature of fluorine atoms, MMA-HFBA polyHIPEs showed remarkable water contact angle of 139°. Furthermore, the addition of fluorinated co-monomer in MMA based HIPEs significantly improved thermal stabilities of these materials with improvement in degradation temperature from 305 °C to 360 °C.

Synthesis of fluorinated polyacrylate surfactant‐free core–shell latex by RAFT‐mediated polymerization‐induced self‐assembly: Effects of the concentration of hexafluorobutyl acrylate

AbstractA simple method for preparing fluorinated polyacrylate surfactant‐free latex was developed by RAFT‐mediated polymerization‐induced self‐assembly, in which the fluorinated polyacrylate copolymers formed a core–shell spherical morphology. The influence of the concentration of hexafluorobutyl acrylate on the properties of latex was systematically studied. The results showed that the average particle size increased, and the monomer conversion gradually increased with increasing the length of the second segment (PHFBA). And the monomer conversion progressively decreased, and average particle size gradually increased as the concentration of monomer (HFBA) increased from 2 wt% to 6 wt%. Furthermore, the thermal stability and the water contact angle of the film increased as the concentration of HFBA increased, and the water contact angle of film can be up to 127.3° when the concentration of HFBA was 6 wt%. XPS also showed that the fluorine‐containing groups well concentrated at the film–air interfaces during the annealing process.

Synthesis and properties of partially biodegradable fluorinated polyacrylate: Poly(l‑lactide)‑co‑poly(hexafluorobutyl acrylate) copolymer

In order to alleviate the environmental pollution from fluoropolymer, the biodegradable poly(l‑lactide) (PLLA) segments were introduced into fluorinated polyacrylate. The PLLA macromonomers with vinyl terminal group and different molecular weight, i.e. 2500, 7400 and 14,700, were synthesized by ring opening polymerization of l‑lactide (LLA) first, then copolymerized with hexafluorobutyl acrylate (HFBA) through free radical copolymerization. By changing the macromonomers and feeding ratio of the macromonomer and HFBA, the poly(l‑lactide)‑co‑poly(hexafluorobutyl acrylate) (PLLA-co-PHFBA) copolymers with different structures were obtained. Structures of the PLLA macromonomers and the copolymers were confirmed by FTIR, 1H NMR and GPC. The crystallization, thermal decomposition resistance, surface hydrophobicity and hydrolytic degradation were also investigated. The results show that the PLLA segments in the copolymers still have the crystallization capacity and the highest crystallinity reaches 36%. PLLA-co-PHFBA-4 with the longest PLLA segments has the highest initial decomposing temperature up to 355 °C. The hydrophobicity of the copolymers is mainly related to the content of PHFBA segments. The length of PLLA segments also have some effect on the hydrophobicity. An obvious mass loss of the copolymers was observed in 35 days under the hydrolytic degradation and it was related to PHFBA content and PLLA segment's length, exhibiting partially biodegradable behavior.

Surfactant-Free Visible-Light-Controlled Emulsion Polymerization toward ABA-Type Amphiphilic Triblock Copolymers

Surfactant-free visible-light-controlled emulsion polymerizations are demonstrated here to synthesize ABA-type amphiphilic triblock copolymers, where A represents the hydrophilic block of poly(acrylic acid) (PAA) and B represents the hydrophobic block, such as poly(butyl acrylate) (PBA), poly(ethyl acrylate) (PEA), poly(trifluoroethyl acrylate) (PTFEA), and poly(hexafluorobutyl acrylate) (PHFBA). The photoiniferter solution polymerization of acrylic acid (AA) in 1,4-dioxane was first performed under air atmosphere and successfully controlled by visible light with the existence of iniferter agent and ascorbic acid. Using the as-synthesized PAA with trithioester end-groups as macro-iniferter agent, ABA-type triblock copolymers were synthesized in an aqueous emulsion system. Chain growth of various hydrophobic B blocks induced self-assembly and micellization. The micelles were in turn swelled by monomers and acted as main reaction loci for the further photoiniferter emulsion polymerizations. All the polymeri...

A Novel Synthetic UV-Curable Fluorinated Siloxane Resin for Low Surface Energy Coating.

Low surface energy materials have attracted much attention due to their properties and various applications. In this work, we synthesized and characterized a series of ultraviolet (UV)-curable fluorinated siloxane polymers with various fluorinated acrylates—hexafluorobutyl acrylate, dodecafluoroheptyl acrylate, and trifluorooctyl methacrylate—grafted onto a hydrogen-containing poly(dimethylsiloxane) backbone. The structures of the fluorinated siloxane polymers were measured and confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Then the polymers were used as surface modifiers of UV-curable commercial polyurethane (DR-U356) at different concentrations (1, 2, 3, 4, 5, and 10 wt %). Among three formulations of these fluorinated siloxane polymers modified with DR-U356, hydrophobic states (91°, 92°, and 98°) were obtained at low concentrations (1 wt %). The DR-U356 resin is only in the hydrophilic state at 59.41°. The fluorine and siloxane element contents were investigated by X-ray photoelectron spectroscopy and the results indicated that the fluorinated and siloxane elements were liable to migrate to the surface of resins. The results of the friction recovering assays showed that the recorded contact angles of the series of fluorinated siloxane resins were higher than the original values after the friction-annealing progressing.

Hydrophobic coating of surfaces by plasma polymerization in an RF plasma reactor with an outer planar electrode: synthesis, characterization and biocompatibility

This paper presents the plasma polymerization of poly(hexafluorobutyl acrylate) (PHFBA) thin films on different substrates in an RF plasma reactor with an outer planar electrode. This reactor configuration allows large area uniformity and fast processing times. Deposition rates of up to 60 nm min−1 were observed. The influence of plasma power and substrate temperature on the deposition rate, structure and wettability of the as-deposited films was investigated. It was observed that better hydrophobicity was obtained at high plasma power and in low temperature conditions. PHFBA thin films deposited on electrospun poly(acrylonitrile) fiber mats under such conditions resulted in superhydrophobic surfaces with contact angle values greater than 150°. In vitro cell studies using human epithelial cells demonstrated the non-toxic nature of the plasma-polymerized PHFBA films.

A cationic fluorosurfactant for fabrication of high-performance fluoropolymer foams with controllable morphology

High internal phase emulsion (HIPE) technique has been of great interest for fabrication of polymer foams with controlled porous structures. However, for fluoropolymers, it has been a challenge to fabricate high-performance foams with controllable porous structures by HIPE due to the lack of suitable surfactant. Here, for the first time, a new type of cationic fluorosurfactant (CFS) is proposed to address this issue. The cationic fluorosurfactant is a diblock copolymer, Poly(2-dimethylamino)ethyl methacrylate-b-Poly(hexafluorobutyl acrylate) (PDMAEMA-b-PHFBA) synthesized by reversible addition−fragmentation chain transfer (RAFT) polymerization. For the prepared fluoro-diblock copolymer having similar fluorosegments to fluoro-monomer, this cationic fluorosurfactant can effectively stabilize high internal phase emulsion (HIPE) system involving hexafluorobutyl acrylate monomer as oil phase, water as internal phase, DVB as cross linker and AIBN as an initiator. Polymerization of the HIPE system finally gave rise to novel flexible fluoropolymer foam, Poly(HFBA-DVB) with a porous morphology which can be tuned simply by the amount of the fluorosurfactant. As a high-performance porous material, the fluoropolymer foam demonstrated not only significant capacities and fast adsorption kinetic for separating various organic oils from water, but also has an excellent thermal stability up to 340°C, indicating significant applications at extreme conditions.

One-pot two-step perfluoroalkylsilane functionalization of multi-walled carbon nanotubes for polyurethane-based composites

A facile approach has been developed to prepare perfluoroalkylsilane functionalized multi-walled carbon nanotubes (MWCNTs) with high grafting content through one-pot two-step reactions. In this process, hydroxyl derivatized MWCNTs (hydroxylized MWCNTs) were covalently functionalized with 3-aminopropyl triethoxysilane by silanisation reaction, and subsequently reacted with hexafluorobutyl acrylate or dodecafluoroheptyl acrylate by Micheal-addition reaction. SEM, FT-IR and TGA characterizations demonstrated that the perfluoroalkylsilane were covalently attached onto the surface of MWCNTs and the higher molecular weight of perfluoroalky acrylate yielded higher grafting content. The perfluoroalkylsilane functionalized MWCNTs showed improved dispersibility and strong interfacial adhesion in/with polyurethane matrix. An increase in the grafting content led to a decrease the crystallinity and hydrogen bonding in the PU composites. As a result, the composites showed increased elongation and unimproved tensile strength, but reduced storage modulus and loss factor. Meanwhile, the higher grafting content offered their composite with higher hydrophobicity, lower percolation threshold and more enhanced electronic conductivity.

Chemical and plasma surface modification of lignocellulose coconut waste for the preparation of advanced biobased composite materials

In this study, surface-modified grinded coconut waste (CW) particles were used as bio-fillers to prepare polymeric composite materials with enhanced properties. Epoxy resin modified with acrylated and epoxidized soybean oil (AESO) was used as the polymer matrix. Two different strategies, namely chemical treatment and plasma enhanced chemical vapor deposition (PECVD) were utilized to modify the surface of CW particles for using them as compatible bio-fillers in composite preparation. Chemical modification involved the treatment of CW particles in a highly alkali NaOH solution, while PECVD modification involved coating of a thin film of hydrophobic poly(hexafluorobutyl acrylate) (PHFBA) around individual CW particle surfaces. Untreated and surface-modified CW particles were used in 10–50wt% for preparation of epoxy composites. FTIR analysis was performed to study the effect of modification on the structures of particles and as-prepared composites. The composite morphologies were investigated by XRD and SE. TGA test was conducted to study the thermal behavior of the composites. Also, the effects of CW particle surface modification on the mechanical and water sorption properties of epoxy resin composites were investigated in detail. It was observed that PECVD-treated CW particles had much more positive effects on the thermal, mechanical, wettability and flammability properties of composites.

Synthesis of cationic fluorinated polyacrylate copolymer by RAFT emulsifier-free emulsion polymerization and its application as waterborne textile finishing agent

Cationic fluorinated polyacrylate emulsifier-free emulsion was synthesized by ab initio RAFT emulsifier-free emulsion polymerization using fluorine-containing amphiphilic block copolymer poly (2-(dimethylamino) ethyl methacrylate)-b-poly (hexafluorobutyl acrylate) (PDMAEMA-b-PHFBA) macro-RAFT agent as a stabilizer, and (2-(acryloyloxy)ethyl)trimethylammonium chloride (DMC) as a cationic monomer. The critical micelle concentration (CMC) of PDMAEMA-b-PHFBA is much smaller than the CMC of SDS, suggesting the excellent micelle-forming ability of PDMAEMA-b-PHFBA in water. The influence of the amount of DMC on emulsion polymerization and finished fabric properties was investigated. The latex particle size and its distribution decreased as the amount of DMC increased from 0 wt% to 2.25 wt%, and then increased afterwards. The cationic fluorinated polyacrylate showed much higher thermal stability than polyacrylate. The water contact angle of the finished fabric decreased with the increase of the amount of DMC. The cationic fluorinated polyacrylate emulsifier-free emulsion was deposited on the surface of fabric characterized by SEM-EDX, and the finished fabrics showed good water repellency. In addition, the finished fabric with fluorinated polyacrylate emulsifier-free emulsion had good antibacterial property against E. coli and S. aureus.

Erratum: RAFT-Mediated Polymerization-Induced Self-Assembly of Poly(Acrylic Acid)-b-Poly(Hexafluorobutyl Acrylate): Effect of the pH on the Synthesis of Self-Stabilized Particles. Polymers, 2016, 8, 207.

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RAFT-Mediated Polymerization-Induced Self-Assembly of Poly(Acrylic Acid)-b-Poly(Hexafluorobutyl Acrylate): Effect of the pH on the Synthesis of Self-Stabilized Particles.

This paper describes a very simple strategy towards self-stabilized poly(acrylic acid)-block-poly(hexafluorobutyl acrylate) (PAA-b-PHFBA) block copolymer particles via reversible addition-fragmentation chain transfer (RAFT)-mediated polymerization-induced self-assembly. Hexafluorobutyl acrylate (HFBA) monomer conversion and number-average molar mass of PAA-b-PHFBA increased gradually with the increase in the pH value of the aqueous phase. When pH < 10, the molecular weight distributions of PAA-b-PHFBA were narrow, however, when the pH was raised to 11.55, PAA-b-PHFBA block copolymers had a broader distribution (ĐM = 1.82) with a serious trailing toward the low molecular weight. Furthermore, the morphology and size of PAA-b-PHFBA latex particles were measured by transmission electron microscopy and dynamic light scattering. The results indicated that the PAA-b-PHFBA latex particles had a clear spherical core-shell structure and the latex particles’ size increased with the increase of pH value.

Cationic fluorinated polyacrylate emulsifier-free emulsion mediated by poly(2-(dimethylamino) ethyl methacrylate)-b-poly (hexafluorobutyl acrylate) trithiocarbonate via ab initio RAFT emulsion polymerization

Abstract Cationic fluorinated polyacrylate emulsifier-free emulsion was synthesized by ab initio RAFT emulsifier-free emulsion polymerization using fluorine-containing amphiphilic block copolymer poly (2-(dimethylamino) ethyl methacrylate)-b-poly (hexafluorobutyl acrylate) (PDMAEMA-b-PHFBA) macro-RAFT agent as a stabilizer. The influence of the amount of hexafluorobutyl methacrylate (HFBMA) on emulsion polymerization and film properties was investigated. The latex particle size and its distribution decreased as the amount of HFBMA increased from 0 wt% to 8 wt%, and then increased afterwards. The latex particles presented spherical-like particles with diameters of 44–56 nm characterized by TEM. The GPC result showed that well-controlled cationic fluorinated polyacrylate with M w /M n = 1.40 was obtained. In addition, XPS revealed that the fluorinated segment preferentially concentrated at the film surface after the annealing process. The water contact angle and thermal stability of the film increased with the increase of the amount of HFBMA.

Cationic UV-curable fluorine-containing polyacrylic epoxy prepolymer with good compatibility

Abstract UV-curable fluorine-containing polyacrylic epoxy prepolymers were prepared by solution free radical polymerization with n -butyl acrylate (BA), glycidyl methacrylate (GMA) and hexafluorobutyl acrylate (HFBA) as co-monomers．The prepolymers with different molecular weight and fluorine content could be photopolymerized with up to 70% epoxy group conversion after 10 min of UV irradiation. They showed satisfactory compatibility and could form homogeneous cured film with commercial photoinitiator and monomer, evidence with transmittance, mechanic and graphic analysis. Also, they exhibited very good surface tension as low as 24.38 dyn/cm and their glass transition temperature and thermo decomposition temperature raised with the increase of fluoro-content.

Thermal stability and surface properties of acrylic PSAs modified by hexafluorobutyl acrylate

The article attempted to prepare special acrylic adhesives with preferable adhesion property and better thermal stability by introducing a fluorinated monomer. The FT-IR result showed that fluorinated monomers and acrylic monomers participated in copolymerization successfully. Furthermore, fluorinated groups performed good compatibility with acrylic resins, based on differential scanning calorimetry curve. According to the TG test under different heating rates, the activation energy of PSAs containing different content of fluorinated monomers was calculated to evaluate the effect of hexafluorobutyl acrylate on heat resistance of PSAs. Then, the findings of contact angle test revealed that the fluorinated PSAs also had rather lower surface energy than ordinary PSAs. Finally, the results of peel strength measurements indicated that the fluorinated PSAs demonstrated excellent adhesion property on various materials, especially low surface energy substrates.

Hydrophobic coating of expanded perlite particles by plasma polymerization

In this study, an RF plasma discharge was employed to deposit thin poly(hexafluorobutyl acrylate) (PHFBA) polymeric films on expanded perlite. A rotating plasma reactor was used to provide effective agitation and mixing of the particles during the depositions. Surface of expanded perlite, a hydrophilic porous material, was successfully transformed into super-hydrophobic due to the highly fluorinated chain of PHFBA. Deposition rates up to 42nm/min were observed. The influences of plasma discharge conditions on wettability and water holding capacity of expanded perlite powders were investigated. Chemical and morphological properties of uncoated and coated expanded perlites were determined by SEM (EDS), FTIR, and contact angle measurements analyses. It is observed that the pulsed plasma approach helps to minimize undesirable monomer fragmentation while providing better film structure. It also should be emphasized that PECVD experiments did not change the morphology of the expanded perlite powders. The water holding capacity of expanded perlite was decreased from 70% down to around 4% upon coating on pulsing mode.