A novel mono‐methacryloyloxy terminated fluorinated macromonomer used for the modification of UV curable acrylic copolymers

A novel macromonomer containing fluorinated units (PHFBMA‐GMA) was synthesized through a two‐step procedure: firstly, hexafluoro‐butyl methacrylate (HFBMA) was polymerized in the presence of functional chain transfer agent 3‐mercaptopropionic acid (MPA) and then the carboxyl acid group terminated polymer was end‐capped with glycidyl methacrylate (GMA). Chemical structures of PHFBMA‐GMA were characterized by gel permeation chromatography, fourier transform infrared spectroscopy (FTIR), and ¹H nuclear magnetic resonance (NMR). Subsequently, PHFBMA‐GMA was employed as reactive surface additives added into UV‐cured polyacrylate to modify UV‐curable coatings. It is convenient to control the tail length of the fluorinated segments in this study by adjusting the ratio of initiator and chain transfer agent. The influence of both the concentration and the molecular weight of PHFBMA‐GMA on the surface properties of UV‐cured films was investigated. With increasing both the concentration and the molecular weight of PHFBMA‐GMA, the surface energy of the UV‐cured films decreased. X‐ray photoelectron spectroscopy was employed to characterize and quantify the surface composition and the results confirm the enrichment of fluorinate atoms on the surface. Moreover, the physical properties of UV‐cured films, such as gel content, water absorption, pencil hardness, adhesion, chemical resistance, mechanical properties, optical transmittance, and thermal properties, were also investigated in detail. The novel macromonomer was economical but effective to modify the properties of the UV‐curable coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43116.     

Design and synthesis of bio-based UV curable PU acrylate resin from itaconic acid for coating applications

UV curable PUA resin was successfully synthesized from polyol based on sustainable resource originated from itaconic acid (IA), isophorone diisocyanate (IPDI) and 2-hydroxyethyl methacrylate (HEMA). A polyol was synthesized by condensation reaction of IA with 16-hexanediol in the presence of p-Toluenesulfonic acid (pTSA). The synthesized PUA resin was characterized for its structural elucidation by using Fourier Transform Infrared Spectrophotometer (FTIR), ¹H and ¹³C NMR spectroscopy. The synthesized UV curable PUA resin was incorporated in varying concentrations in conventional PUA coating system. The effects of varying concentration of synthesized UV curable PUA resin on rheology, crystallinity, thermal and coating properties were evaluated. The rheological behavior of the resins were evaluated at variable stress and result showed decrease in viscosity of resin as concentration of synthesized UV curable PUA resin increases in conventional PUA resin. The cured coatings have been evaluated for glass transition temperature (T_g) and thermal behavior by differential scanning calorimeter and thermogravimetric analysis respectively. The degree of crystallinity of the coatings was determined from X-ray diffraction patterns using the PFM program. It was found that increase in the mass proportion of IA based PUA in coatings, the coating becomes more rigid and crystalline. The synthesized UV curable PUA coatings showed interesting mechanical, chemical, solvent and thermal properties as compared to the conventional PUA. Further, cured coatings were also evaluated for gel content and water absorption.     

Performance of white light emitting diodes prepared by casting wavelength‐converting polymer on InGaN devices

UV‐curable siloxane oligomers prepared by a hydrosilylation reaction were used as encapsulant. Two fluorescent copolymers with emission covering the range of green and red light were synthesized and blended with the UV‐curable siloxane oligomers and photoinitiator to make the wavelength‐converting polymer (WCP). WCP was casted on blue light emitting InGaN diodes and UV cured to fabricate white light emitting diodes (WLEDs). Effects of monomer compositions on the fluidity of uncured oligomer, together with the optical, thermal, and mechanical properties of the cured polysiloxane were studied. We also investigated the influence of red fluorescent polymer which was comprised of repeating units of dioctylfluorene, bisthienyl‐benzothiadiazole, and benzothiadiazole segments on the color rendering index, correlated color temperature, and luminous efficacy of WLED. Because of the good match between the absorption and emission features of the segments in the fluorescent copolymers, white LEDs can be produced by fluorescent copolymer blends which can support incomplete energy transfer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45210.     

A novel UV‐curable epoxy acrylate resin containing arylene ether sulfone linkages: Preparation,characterization, and properties

UV‐curing processes are used in industrial applications because of their advantages such as high‐speed applications and solvent‐free formulations at ambient temperature. UV‐curable epoxy acrylate resins containing arylene ether sulfone linkages (EAAES) were synthesized through the condensation of bis(4‐chlorophenyl)sulphone and bisphenol‐A, followed by end‐caping of epichlorohydrin and subsequently acrylic acid. UV‐cured coatings were formulated with epoxy acrylates, reactive diluents such as pentaerythritol tri‐acrylate and pentaerythritol dia‐crylate and photoinitiator. Fourier transfer infrared, ¹H NMR, and thermal gravimetrical analysis were employed to investigate the structures and thermal properties of the EAs films. The introduction of EAAES into epoxy acrylate substantially improves its thermal properties and thermo‐oxidative stability at high temperatures. In addition, the acrylate containing arylene ether sulfone linkages can also improve pencil hardness and chemical and solvent resistance of the epoxy acrylate. The obtained UV‐curable epoxy acrylate containing arylene ether sulfone linkages is promising as oligomer for UV‐curable coatings, inks, and adhesives in some high‐tech regions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41067.     

Preparation and evaluation of epoxy methacrylate UV‐curable coatings containing phthalazinone

Epoxy methacrylate resin (EMA) UV‐curable coatings exhibit high reactivity, low viscosity and excellent chemical resistance in environmentally friendly coatings. A novel EMA containing phthalazinone moieties for high temperature resistant UV‐curable coatings was synthesized. The formulations were cured with hexanediol diacrylate (HDDA) and trimethylol propane triacrylate (TMPTA) as reactive diluents promoted by a photoinitiator, and then interpenetrating polymer networks were generated. The mechanical, chemical and thermal properties of the clear coatings were characterized using Chinese National Standard methods (GB). EMA was used with UV radiation curing in combination with 6.7 wt% of HDDA and 13.4 wt% of TMPTA, and the properties of the cured films were as follows: pencil hardness of 5 H, 30% NaOH resistance for 30 days, 15% HCl resistance for 10 days, 3% NaCl resistance for 30 days and 5% weight loss temperature of 300.5 °C. EMA UV‐curable coatings containing phthalazinone exhibit excellent chemical and thermal stability, and could be potential candidates for UV‐curable zero volatile organic compound coatings applied in the fields of salt spray corrosion, strong radiation and high‐temperature resistance. Copyright © 2009 Society of Chemical Industry     

Synthesis,characterization, and properties of silicone–epoxy resins

Silicone–epoxy (SiE) resins were synthesized through the hydrolytic condensation of 2‐(3,4‐epoxycyclohexylethyl) methyldiethoxysilane (EMDS) and the cohydrolytic condensation of EMDS with dimethyldiethoxysilane. Structural characterization was carried out by ¹H‐NMR, ²⁹Si‐NMR, and mass spectrometry analysis; the resins were linear oligomers bearing different numbers of pendant epoxy groups, and the average number of repeat Si O units ranged from 6 to 11. Methyhexahydrophthalic anhydride was used to cure the SiE resins to give glassy materials with high optical clarity. The cured SiE resins showed better thermal stability and higher thermal and UV resistances than a commercial light‐emitting diode package material (an epoxy resin named CEL‐2021P). The effect of the epoxy value on the thermal and mechanical properties and the thermal and UV aging performances of the cured SiE resins were investigated. The SiE resins became more flexible with decreasing epoxy value, and the resin with the moderate epoxy value had the highest thermal and UV resistances. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Self‐assembled nanostructures: preparation,characterization, thermal,optical and morphological characteristics of amphiphilic diblock copolymers based on poly(2‐hydroxyethyl methacrylate‐block‐N‐phenylmaleimide)

A series of well‐defined amphiphilic poly[(2‐hydroxyethyl methacrylate)‐block‐(N‐phenylmaleimide)] diblock copolymers containing hydrophilic and hydrophobic blocks of different lengths were synthesized by atom transfer radical polymerization. The properties of the diblock copolymers and their ability to form large compound spherical micelles are described. Their optical, morphological and thermal properties and self‐assembled structure were also investigated. The chemical structure and composition of these copolymers have been characterized by elemental analysis, Fourier transform infrared, ¹H NMR, UV–visible and fluorescence spectroscopy, and size exclusion chromatography. Furthermore, the self‐assembly behavior of these copolymers was investigated by transmission electron microscopy and dynamic light scattering, which indicated that the amphiphilic diblock copolymer can self‐assemble into micelles, depending on the length of both blocks in the copolymers. These diblock copolymers gave rise to a variety of microstructures, from spherical micelles, hexagonal cylinders to lamellar phases. © 2013 Society of Chemical Industry     

A novel flame retardant UV‐curable vinyl ester resin monomer based on industrial dipentene: Preparation,characterization, and properties

A novel bio‐based and flame‐retardant UV‐curable vinyl ester resin (VER) monomer named Diglycidyl ester of maleinized dipentene modified with dibutyphosphate and methacrylic anhydride (MDDMD) was synthesized from industrial dipentene via Diels‐Alder reaction, glycidylation, epoxy ring‐opening reaction, and esterification. Its chemical structures were characterized by Fourier transform infrared (FTIR) analysis and proton nuclear magnetic resonance (¹H‐NMR). In order to improve its flexibility, we prepared a series of copolymers under UV light radiation by mixing it with certain proportions of poly(ethylene glycol) dimethacrylate‐200 (PEGDMA‐200) which contained flexible groups. Their tensile property, curing degrees (CD), hardness, limiting oxygen index (LOI), dynamic mechanical thermal properties, and thermostability were all investigated. The cured mixed resins have a relatively high tensile strength of 10.05 MPa and curing degrees up to 92.5%. Both hardness (range: 50 to 23 HD) and LOI (range: 22.8% to 24.4%) of cured resins are improved with the increase of MDDMD content. Dynamic mechanical analysis (DMA) shows that their glass transition temperatures rise with the increase of MDDMD content. Thermogravimetric analysis (TGA) shows that the thermal stability of cured resins is enhanced with the increase of PEGDMA‐200 content, as the main thermal initial decomposition temperatures are all above 260 °C and char yield at 800 °C are above 18.10%. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44084.     

Synthesis of UV‐curable difunctional silane monomer based on 3‐methacryloxy propyl trimethoxysilane (3‐MPTS) and its UV‐curing characteristics and thermal stability

In the present investigation, silicon containing UV‐curable difunctional monomer was synthesized by reacting 3‐methacryloxy propyl trimethoxysilane (3‐MPTS) with acrylic acid using anhydrous ether as a solvent under inert atmosphere. The synthesized acryloxymethacryloxy silane monomer was characterized by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. The silane monomer along with 4 wt % photoinitiator (Darocure 1173) was cured under UV‐light for different exposure time. The curing characteristic of the monomer was investigated using FTIR spectroscopy. The conversion of the double bond due to curing has been evaluated from the peak intensity of the C?C double bond (at 1636 cm^?1) in the FTIR spectrum considering the peak intensity at 1720 cm^?1 due to C?O as internal standard. The maximum double bond conversion is observed to be 72%. The optimum cure time for the silane monomer has been estimated to be 7.8 sec. The UV‐cured sample decomposes at 440°C. The char residue is 35% at 700°C. The synthesized UV‐curable silane monomer may be useful for UV‐coating formulations, for fabrication of 3D‐objects by lithographic technique and as a precursor for organic–inorganic hybrid materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of UV-curable polysiloxanes containing methacryloxy/fluorinated side groups and the performances of their cured composite coatings

Three novel UV-curable polysiloxanes consisting of polysiloxane backbone with methacryloxy/fluorinated side groups were synthesized, and their structures were characterized by FT-IR, ¹H NMR and ¹³C NMR. A series of UV-cured composite coatings based on the synthesized polysiloxanes and an epoxy methacrylate were obtained through photopolymerization. Their gel content, flexibility, hardness, gloss, contact angle, thermal behavior as well as water absorption ratio were investigated. Results found that the siloxane component could enhance the flexibility and gloss of coatings, while the presence of fluorinated groups could improve the hardness. The combination of silicon and fluorine in the same polymer could increase thermal stability and water resistance of the coatings and decrease their surface energy simultaneously. The observation of the fractured-surface morphology showed that the polysiloxanes could be well dispersed in the epoxy methacrylate to some extent. A suitable addition of such polysiloxane in photocurable coating matrixes may provide excellent properties for the cured coatings and widen their applications.     

Synthesis and application of novel UV-curable hyperbranched methacrylates from renewable natural tannic acid

With a view to developing high performance UV curable coatings with high renewable contents, acrylated epoxidized soybean oil (AESO) was combined with a novel kind of biorenewable tannic acid-based hyperbranched methacrylates (TAHAs). The TAHAs were synthesized by ring-opening reaction of glycidyl methacrylate (GMA), glycidyl ester of Versatic acid (CE10) and natural tannic acid (TA). The epoxy groups of GMA and CE10 were involved in the ring-opening reaction with the hydroxyl groups of TA while residual methacrylate groups can carry out photopolymerization. By controlling the ratio of GMA and CE10, TAHAs with varying degree of methacrylate groups have been prepared. The synthesized TAHAs were formulated into acrylated epoxidized soybean oil (AESO) based UV curable coatings to produce the biorenewable materials based UV curable coatings. The effects of TAHAs on AESO coated film properties of pendulum hardness, flexibility and adhesion were investigated. Mechanical properties, thermal properties and biodegradability of the cured films were also evaluated. With the incorporation of TAHAs, the hardness, adhesion, tensile strength of the cured coating films were remarkably improved, which were attributed to the unique structure of hyperbranched methacrylates. Meanwhile, the biorenewable content was not greatly decreased due to the biorenewable character of tannic acid in TAHAs. These results showed that TAHAs as efficient toughening agents could produce UV-curable coatings of balanced coating performance with reasonably high biorenewable content. Moreover, the environment degradability of AESO-based cured films was also enhanced after the addition of TAHAs.     

Synthesis of a branched photosensitive copolymer and its application for negative‐type photoresists

Novel branched copolymers, poly(styrene‐alt‐maleic anhydride) (BPSMA), were synthesized through mercapto chain‐transfer polymerization with styrene, maleic anhydride (MA), and 4‐vinyl benzyl thiol (VBT). Then, the hydroxyl of hydroxyethyl methacrylate was reacted with MA to synthesize branched photosensitive copolymers, p‐BPSMAs. Fourier transform IR spectroscopy and ¹H‐NMR indicated that the synthesis was successful. Gel permeation chromatography indicated that the molecular weight decreased with increasing content of VBT. The thermal properties were characterized by thermogravimetric analysis; the results show that the thermal decomposition temperature of the BPSMAs was greatly enhanced. Real‐time IR was used to evaluate the UV‐curable kinetics of the p‐BPSMAs; the results show that the p‐BPSMAs could rapidly photopolymerize under UV irradiation in the presence of photoinitiators. Moreover, the photoresist based on the p‐BPSMAs exhibited improved photosensitivity when the VBT content increased, and the photoresist with 12 mol % VBT content had a low value of the dose that retained 50% of the original film thickness (10 mJ/cm²), and a 50‐μm resolution could be achieved compared to a linear photoresist. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42838.     

Preparation and performance on polycarbonate of B/F/Si‐containing hybrid coatings

A series of UV‐curable B/F/Si‐containing hybrid coatings was prepared by the anhydrous sol‐gel technique. The chemical structure of the coatings was characterized by FTIR, RTIR, and ¹HNMR techniques. The UV‐curable coatings were applied to polycarbonate substrates. The physical and mechanical properties of the UV‐cured coatings, such as pendulum hardness, pencil hardness, contact angle, gel content, MEK rubbing test values, tensile strength, abrasion resistance, and gloss, were examined. Thermal gravimetric analysis (TGA) was done. The relative flammability of the hybrid coatings was tested by the limiting oxygen index (LOI) method. Results of all analyses conducted on the free films and coatings are discussed. J. VINYL ADDIT. TECHNOL., 19:39–46, 2013. © 2013 Society of Plastics Engineers     

Preparation and characterization of acrylonitrile‐ethyl methacrylate copolymers and the effect of LiClO4 salt on electrical properties of copolymer films

Copolymers of poly(acrylonitrile‐co‐ethyl methacrylate), P(AN‐EMA), with three different EMA content and parent homopolymers were synthesized by emulsion polymerization. The chemical composition of copolymers were identified by FTIR, ¹H‐NMR and ¹³C‐NMR spectroscopy. The thermal properties of copolymers were modified by changing the EMA content in copolymer compositions. Various amounts of LiClO₄ salt loaded (PAN‐co‐PEMA) copolymer films were prepared by solution casting. The dielectric properties of these films at different temperatures and frequencies were investigated. It was found that the dielectric constant and ac‐conductivity of copolymer films were strongly influenced by the salt amounts and EMA content in copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Novel copolymers for electroluminescent devices

Two novel luminescent block copolymers (CE–PPV and CE–DMPPV), containing alternating distyrylbenzene [poly(phenylene vinylene) model oligomer] as light‐emitting units and crown‐ether segments as ionic conductive and spacer units were synthesized by use of a Wittig reaction between the dialdehyde monomer and 1,4‐xylylene‐bis(triphenylphosphonium bromide) or 1,4‐bis(triphenylphosphoniomethyl)‐2,5‐dimethoxybenzene dichloride. The synthesized polymers were characterized with FTIR, ¹H‐NMR, UV–Vis, differential scanning calorimetry, and gel permeation chromatography. The number‐average molecular weights were 6896 with a polydispersity index of 1.75 for CE–PPV, and 9301 with a polydispersity index of 2.474 for CE–DMPPV, respectively. The decomposition temperatures and the glass‐transition temperatures were in the range of 395–411°C and 75–77°C, respectively. The electrochemical properties of the copolymers were evaluated and the highest occupied molecular orbital and the lowest unoccupied molecular orbit energy levels of the copolymers were estimated by cyclic voltammetry. Efficient light‐emitting diodes were successfully fabricated. The synthesis, characterization, and electroluminescent properties of the polymers are reported in this study. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3316–3321, 2002     

Synthesis and characterization of poly(dimethylamino ethyl methacrylate)–poly(ethylene oxide)–poly(dimethylamino ethyl methacrylate) triblock copolymers

Novel, monodispersed, and well‐defined ABA triblock copolymers [poly(dimethylamino ethyl methacrylate)–poly(ethylene oxide)–poly(dimethylamino ethyl methacrylate)] were synthesized by oxyanionic polymerization with potassium tert‐butanoxide as the initiator. Gel permeation chromatography and ¹H‐NMR analysis showed that the obtained products were the desired copolymers with molecular weights close to calculated values. Because the poly(dimethylamino ethyl methacrylate) block was pH‐ and temperature‐sensitive, the aqueous solution behavior of the polymers was investigated with ¹H‐NMR and dynamic light scattering techniques at different pH values and at different temperatures. The micelle morphology was determined with transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and photopolymerization of acrylic acrylate copolymers

Acrylate‐functionalized copolymers were synthesized by the modification of poly(butyl acrylate‐co‐glycidyl methacrylate) (BA/GMA) and poly(butyl acrylate‐co‐methyl methacrylate‐co‐glycidyl methacrylate). ¹³C‐NMR analyses showed that no glycidyl methacrylate block longer than three monomer units was formed in the BA/GMA copolymer if the glycidyl methacrylate concentration was kept below 20 mol %. We chemically modified the copolymers by reacting the epoxy group with acrylic acid to yield polymers with various glass‐transition temperatures and functionalities. We studied the crosslinking reactions of these copolymers by differential scanning calorimetry to point out the effect of chain functionality on double‐bond reactivity. Films formed from acrylic acrylate copolymer precursors were finally cured under ultraviolet radiation. Network heterogeneities such as pendant chains and highly crosslinked microgel‐like regions greatly influenced the network structure and, therefore, its viscoelastic properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 753–763, 2002     

Micropatterning of polymethacrylates by single‐ or two‐photon irradiation using π‐conjugated o‐nitrobenzyl ester phototrigger as side chains

A new single‐/two‐photon sensitive monomer, (E)‐5‐(4‐ethoxystyryl)?2‐nitrobenzyl methacrylate (ENbMA), was synthesized and copolymerized with methyl methacrylate (MMA) to form a series of photosensitive copolymers P(ENbMA–MMA)s that were well characterized by ¹H NMR and GPC. The photochemical and photophysical properties of both photosensitive monomer and copolymers upon visible light irradiation were studied by UV–Vis, FTIR, and HPLC spectra, which confirmed that 5‐(4‐ethoxystyryl)‐2‐nitrobenzyl ester can be photolyzed effectively with generation of the corresponding 5‐(4‐ethoxystyryl)‐2‐nitrosobenzaldehyde and carboxylic acid groups. The successful photocleavage endowed the optimized copolymers with excellent micropatterning property due to the effective generation of alkaline‐soluble carboxylic acid groups. Moreover, the high two‐photon absorption cross‐sections (over 20 GM at 800 nm) and the comparable photolysis upon two‐photon NIR light irradiation of the chromophores provided the copolymers with significant application in two‐photon microfabrication. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4099–4106, 2013     

Synthesis,characterization, and UV‐curing properties of silicon‐containing (Meth)acrylate monomers

Eight different silicon‐containing (meth)acrylate monomers are synthesized by the substitution reaction of chlorosiloxanes with 2‐hydroxyethyl methacrylate or 2‐hydroxyethyl acrylate. Their molecular structures are confirmed by IR, ¹H‐NMR, and ¹³C‐NMR spectroscopic analyses. The effects of silicon content on the UV‐curing behavior, physical, surface, and thermal properties are investigated. The UV‐curing behavior is analyzed by photo differential scanning calorimetry. The surface free energy of the UV‐cured film is calculated from contact angles measured using the Lewis acid‐base three liquids method. The silicon‐containing (meth)acrylate monomers perform much better than traditional (meth)acrylate monomers on UV‐curing. The silicon‐containing monomers have higher final conversions and fast UV‐curing rates in photopolymerization. The surface free energy decreases with increasing silicon content, because silicon in the soft segment is transferred to the surface, producing a UV‐cured film; this is confirmed by X‐ray photoelectron spectroscopy measurements. All these advantageous properties enable these synthetic silicon‐containing monomers to perform better in applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and ultraviolet‐curing behaviors of vinyl ether functionalized polyurethane oligomers

The vinyl ether functionalized oligomer is one of the most basic components of vinyl ether functionalized materials for cationic UV‐curable coatings. In this study, three types of vinyl ether functionalized polyurethane oligomers (i.e., polyether, polyester, and polydimethylsiloxane) were synthesized with diisocyanate, diol, and hydroxyethyl vinyl ether. These oligomers were characterized by IR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. The effect of the raw material ratio on the oligomer, UV‐curing behaviors, and thermal properties of these oligomers were investigated. The UV‐curing behavior was analyzed by real‐time Fourier transform infrared spectroscopy. The vinyl ether terminated polyester urethane oligomer exhibited better UV curing, with a higher final conversion and maximum UV‐curing rates. In addition, the light intensity was enhanced for oligomers with better UV‐curing properties. Research on these vinyl ether functionalized oligomers is essential to the development and applications of cationic vinyl ethers systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40501.