Photo‐Induced atom transfer radical polymerization with nanosized α‐Fe2O3 as photoinitiator

Photo‐induced atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was achieved in poly(ethylene glycol)‐400 with nanosized α‐Fe₂O₃ as photoinitiator. Well‐defined poly(methyl methacrylate) (PMMA) was synthesized in conjunction with ethyl 2‐bromoisobutyrate (EBiB) as ATRP initiator and FeCl₃·6H₂O/Triphenylphosphine (PPh₃) as complex catalyst. The photo‐induced polymerization of MMA proceeded in a controlled/living fashion. The polymerization followed first‐order kinetics. The obtained PMMA had moderately controlled number‐average molecular weights in accordance with the theoretical number‐average molecular weights, as well as narrow molecular weight distributions (M_w/M_n). In addition, the polymerization could be well controlled by periodic light‐on–off processes. The resulting PMMA was characterized by ¹H nuclear magnetic resonance and gel permeation chromatography. The brominated PMMA was used further as macroinitiator in the chain‐extension with MMA to verify the living nature of photo‐induced ATRP of MMA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42389.     

Photoinitiating behavior of bifunctional photoinitiator containing α‐hydroxyalkylphenone group on free‐radical polymerization

Photoinitiating behaviors of bis[4‐(2‐hydroxy‐isopropionyl)]ether photoinitiator on free‐radical polymerization have been investigated. The kinetics of photopolymerization initiated by the photoinitiator was studied by means of differential photocalorimetry. The bifunctional photoinitiator showed comparative performance with those commercial photoinitiators with monofunctional chromophoric group. The effect of UV intensity on the polymerization rate was investigated, and the value of exponential factor was found to be 0.5 at the beginning of polymerization, suggesting that the photopolymerization initiated by bis[4‐(2‐hydroxy‐isopropionyl)]ether followed biradical termination mechanism. Photosensitizer triethylamine improves the initiating efficiency while oxygen is shown to restrict polymerization in this system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5297–5302, 2006     

Synthesis and characterization of biodegradable crosslinked polymers from 5‐hydroxylevulinic acid and α,ω‐diols

Novel biodegradable chemically crosslinked polymers, poly(5‐hydroxylevulinic acid‐co‐α,ω‐diol)s (PHLA‐diols), were synthesized from 5‐hydroxylevulinic acid and α,ω‐diols and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. The gel content, swelling ratio, tensile properties, and hydrolytic degradation behaviors were also measured and assessed. The glass‐transition temperature of the PHLA‐diols could be adjusted within a wide range (?50 to 30°C) by the type and feed ratio of the diol. Because of the low glass‐transition temperature and crosslink structure, they exhibited certain elastic properties. The tensile modulus, strength, and elongation at break measured at 37°C were 1.4–6.3 MPa, 0.8–1.6 MPa, and 10–25%, respectively. These polymers could be hydrolytically degraded. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

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 polymerizations of novel bisphosphonate‐containing methacrylates derived from alkyl α‐hydroxymethacrylates

The synthesis and polymerizations of four novel bisphosphonate‐containing monomers are reported. The monomers were synthesized from reaction of ethyl and tert‐butyl α‐bromomethacrylates with 3,3‐bis(diethoxyphosphoryl)propanoic acid or with tetraethyl 4‐hydroxybutane‐1,1‐diyldiphosphonate. Their thermal bulk polymerizations, photopolymerizations and copolymerizations with poly(ethylene glycol) methyl ether methacrylate were investigated. The homopolymerizations resulted in polymers with values of 25 000–83 000 g mol^?1; the copolymerizations yielded soluble polymers with 22–34% incorporation of the new monomers; the photopolymerizations gave some structure–reactivity correlation; and one of the homopolymers, upon hydrolysis of its bisphosphonate groups, could interact with hydroxyapatite. © 2013 Society of Chemical Industry     

Post‐oligomerization of α‐olefin oligomers: A route to single‐component and multicomponent synthetic lubricating oils

This article describes a synthetic route to single‐component and multicomponent base stocks for synthetic lubricated oils. The synthesis was carried out in two stages. First, oligomers of α‐olefins (1‐hexene, 4‐methyl‐1‐pentene, and 1‐decene) were prepared via reactions catalyzed by metallocene catalysts. The distribution of the oligomers with respect to their oligomerization number could be controlled by the reaction temperature. The oligomer mixtures were then fractionated, and the lightest components, dimers and trimers, were separated. Finally, the latter materials, branched α‐olefins containing vinylidene double bonds, were further oligomerized with cationic catalysts. One such material prepared in the two‐stage process, the dimer of the 1‐decene dimer (C₄₀ product), has a kinematic viscosity of 6.4 cs at 100°C and a viscosity index of 147. It represents the first example of a single‐component base stock for synthetic lubricating oils. The post‐oligomerization procedure was performed on unfractionated oligomer mixtures as well, leading to an improved distribution of the final materials with respect to the carbon atom number. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Allyl ether‐modified unsaturated polyesters for UV/air dual‐curable coatings. I: Synthesis and characterization of the oligomers and their cured films

Allyl ether (AE)‐modified unsaturated polyester oligomers were synthesized from polyethylene glycol (PEG), maleic anhydride (MAH), and trimethylolpropane mono allyl ether (TMPAE), and characterized by Fourier transform infrared (FTIR) spectra. The UV/air dual‐curable coatings were prepared from the oligomers using vinyl ether (VE) as a reactive diluent. FTIR spectra showed that C?C bonds in the coating composition had polymerized partially after cured by UV or air. The investigation of rheological behavior of the dual curable composition suggested that all the systems belonged to pseudoplastic fluid, and the increasing allyloxy content in oligomer resulted in a higher viscosity. Differential scanning calorimetry (DSC) analysis showed that the increasing TMPAE‐PEG molar ratio resulted in lower T_g, and all samples had the same glass transition temperature irrespective of the type of curing. The results of TGA for cured films indicated that UV‐cured film had better thermal stability than the air‐cured one. The air‐cured film showed superior pencil hardness, impact strength, and flexibility to the UV‐cured counterpart. However, the air‐cured film had poor adhesion and electric resistance properties. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2765–2770, 2004     

Synthesis and characterization of novel oligomeric poly(styrene‐co‐acrylonitrile)–clay complexes

Oligomeric poly(styrene‐co‐acrylonitrile) quaternary ammonium salts were prepared through reactions of trimethylamine with corresponding poly(styrene–acrylonitrile–vinyl benzyl chloride)s, which were synthesized by the free‐radical polymerization of a mixture of styrene, acrylonitrile, and vinyl benzyl chloride. Then, oligomeric poly(styrene‐co‐acrylonitrile)‐modified clays were prepared through the cation exchange of the sodium ions in the clay with the corresponding poly(styrene‐co‐acrylonitrile) quaternary ammonium salts. The poly(styrene–acrylonitrile–vinyl benzyl chloride)s, poly(styrene‐co‐acrylonitrile) quaternary ammonium salts, and their clay complexes were characterized with infrared spectroscopy, gel permeation chromatography, thermogravimetric analysis, proton nuclear magnetic resonance, X‐ray diffraction, and transmission electron microscopy. X‐ray diffraction and transmission electron microscopy studies showed that these novel clay complexes were well intercalated. Furthermore, thermogravimetric analysis data indicated that this series of polymerically modified clays had high enough thermal stability for nanocomposites by melt blending. The thermal treatment of one of these novel clays at 250°C under nitrogen was also conducted. Solubility and infrared studies of this thermally treated clay complex revealed that a novel polyimine/enamine structure clay complex had been formed in the gallery of the clay. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Polymer precursor to diamondlike carbon prepared by the polymerization of α,α,α‐trichlorotoluene and acetonitrile

A novel liquid/solid two‐phase reaction of α,α,α‐trichlorotoluene (PhCCl₃) and acetonitrile (AN) has been discovered that produces a carbon‐based polymer with diamondlike structure at the atomic level. The solid phase is potassium hydroxide particles, and the liquid phase is a tetrahydrofuran solution of PhCCl₃ and AN containing a certain amount of tetrabutylammonium bromide as a phase‐transfer catalyst. The structure of the carbon‐based polymer has been characterized by elemental analysis, Fourier transform infrared spectroscopy, and ¹H‐ and ¹³C‐NMR spectroscopy. The pyrolysis of the carbon‐based polymer at 800°C under a nitrogen atmosphere leads to the formation of a diamondlike carbonaceous material according to the results of X‐ray photoelectron spectroscopy and Raman spectroscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 16–23, 2003     

Water‐soluble and polymerizable thioxanthone photoinitiator containing imidazole

A novel free radical photoinitiator, 3‐allyl‐1‐[2‐hydroxy‐3‐(thioxanthen‐9‐one‐2‐yl)oxypropyl]imidazolium chloride ([AIPTX]Cl), is synthesized by the addition reaction of 2‐(2,3‐epoxy)propoxylthioxanthone (ETX) with a heterocyclic compound imidazole firstly, and the achieved intermediate 1‐[2‐hydroxy‐3‐(thioxanthen‐9‐one‐2‐yl)oxypropyl]imidazole (IPTX) is then reacted with allyl chloride. IPTX is chosen to evaluate the photoefficiency of [AIPTX]Cl. FTIR and ¹H‐NMR confirm the structures of [AIPTX]Cl and IPTX. UV‐Vis spectra of the two photoinitiators are similar and both exhibit the maximal absorption about 400 nm. Fluorescence spectra show [AIPTX]Cl/IMZ has slightly higher fluorescence intensity than IPTX system. Photopolymerization studies indicate that [AIPTX]Cl/IMZ is more efficient for the polymerization of water‐soluble monomer than IPTX. Moreover, due to its advantages of water solubility and polymerizability, [AIPTX]Cl is an environmental‐friendly photoinitiator and has potential for application in UV‐curing systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40659.     

Phosphonic acid‐containing polysulfones as anticorrosive layers

As a part of research work to elaborate polymeric materials for metal corrosion protection, we have developed a new family of phosphonic acid‐containing polymers. The synthesis and the characterization of polysulfones bearing alkyl phosphonate ester side groups are first described. These polymers are synthesized by direct polycondensation of a phosphonate ester‐containing bisphenol by aromatic nucleophilic substitution. The physicochemical properties of the resulting polymers are described. Acidic hydrolysis of phosphonate esters results in the formation of phosphonic acid groups. A series of phosphonic acid‐containing polysulfones is therefore obtained and characterized. A preliminary evaluation of the anticorrosive properties of these polymers is described. In 0.25M Na₂SO₄ solution, the corrosion rate of a polymer‐coated mild steel sample is much lower than of the free metal substrate. These results suggest that phosphonic acid‐containing polysulfones might be interesting as anticorrosive coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41890.     

UV‐activated silicone oligomer cross‐linking through photoacid and photobase organocatalysts

Diphenyl iodonium hexafluorophosphate salt and N‐alkyl morpholino acetophenone were shown to be effective photocatalyst generators for the cross‐linking of α,ω‐silanol terminated silicone oligomers. These two photoacid and photobase‐induced polycondensation pathways provided an attractive and efficient alternative to toxic and expensive organometallic catalysts. The utility of this novel UV‐curing process was demonstrated with a combination of time‐resolved infrared spectroscopy to follow the fast reaction kinetics and solid‐state ²⁹Si nuclear magnetic resonance to investigate the polysiloxane network. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39875.     

Synthesis and characterization of Schiff‐base‐containing polyimides

Benzyl bisthiosemicarbazone and its complexes with nickel (NiLH₄) and copper (CuLH₄) were used as diamine monomers for the synthesis of new Schiff‐base polyimides. The solution polycondensation of these monomers with the aromatic dianhydrides afforded metal‐containing Schiff‐base polyimides with inherent viscosities of 0.98–1.33 dL/g (measured in N‐methyl‐2‐pyrrolidone at 25°C). The polyimides were generally soluble in a wide range of solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, tetrahydrofuran, dimethyl sulfoxide, tetrachloroethane, hexamethylene phosphoramide, N‐methyl‐2‐pyrrolidone, ethyl acetate, and pyridine at room temperature. The initial degradation temperatures of the resultant polyimides fell in the range of 220–350°C in nitrogen with char yields ranging from 36 to 64% at 700°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A water‐soluble supramolecular‐structured photoinitiator between methylated β‐cyclodextrin and 2,2‐dimethoxy‐2‐phenylacetophenone

A water‐soluble supramolecular‐structured photoinitiator (SSPI) was synthesized by supramolecular self‐assembling between methylated β‐cyclodextrin (MβCD) and hydrophobic 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA). The structure of SSPI was characterized by X‐ray diffraction, FTIR, ¹H NMR, UV–vis, and fluorescence spectra. The results indicated that MβCD and DMPA had formed 1 : 1 inclusion complex in methanol solution. The binding constant (K) for the complex was 7.51 × 10²M^?1. SSPI could be dissolved in water easily and its water‐solubility was 15.3 g/100 mL. SSPI was the more efficient photoinitiator than DMPA for the photopolymerization of acrylamide (AM) in homogeneous aqueous system. The conversion for photopolymerization of trimethylolpropane triacrylate system initiated by SSPI was similar to that initiated by DMPA. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and characterization of poly[(methyl methacrylate)‐co‐(methacrylic acid)] for a UV‐sensitive aqueous base developable lithographic plate

Syntheses of the copolymers of methyl methacrylate and methacrylic acid were carried out by free radical chain polymerization in the presence of benzoyl peroxide (BPO) as an initiator. The effects of the monomer ratio and polymerization time on the averaged molecular weights, polydispersity index, and glass transition temperature were investigated. FTIR and NMR were used for functional group characterization, GPC for average molecular weights and the distribution, elemental analysis for CHO content, and DSC for the glass transition temperature. The copolymers were mixed with tripropylene glycol diacrylate (TPGDA) and trimethylol propane ethoxylated triacrylate (TMPEOTA), 2‐hydroxy‐2‐methyl‐1‐phenyl‐propan‐1‐one (Darocur® 1173) and benzophenone (Darocur® BP) with anthraquinone for visibility of images. The photosensitive coating was spin‐coated onto the anodized aluminum plate on which a thin film was formed. The wet film was then coated with PVA solution as an oxygen barrier layer. The plate assembled with a control wedge and a black color separation film was exposed to UV radiation at different exposure times. The plate was developed in a dilute alkaline developer. The resulting plate was evaluated for its reproduction properties in terms of surface properties (hydrophilic/hydrophobicity) by contact angle measurement of image/nonimage areas, resolution by microline, tone reproduction, and adhesion tests. The article describes the results of the syntheses, characterizations, and uses of the copolymer as a binder of a negative, lithographic printing plate. The present lithographic printing plate is good for a medium viscosity printing ink to produce medium printing quality on uncoated paper. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1829–1837, 2002     

Novel sulfur—containing benzophenone derivative as radical photoinitiator for photopolymerization

A novel, highly efficient, polymerizable sulfur‐containing photoinitiator for free radical polymerization, benzophenone thio‐acetic acid (BP‐S‐CH₂‐COOH) was synthesized, characterized, and compared to photoinitiator parameters of the benzophenone (BP) and benzophenone/(phenylthio)acetic acid couple. The photoinitiator possesses a greatly redshifted UV maximal absorption in comparison to BP. Laser flash photolysis studies suggest that photoinitiator radicals are generated by photocleavage of C? S bond. Photopolymerization of 2‐ethyl‐2‐(hydroxymethyl)‐1,3‐propanediol triacrylate (TMPTA) demonstrated that one‐component system BP? S? CH₂? COOH is more efficient for polymerization than two‐component system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and nonlinear optical characterization of copolymers containing alternating 3,4‐dialkoxythiophene and (1,3,4‐oxadiazolyl)benzene units

We report the synthesis and linear and third‐order nonlinear optical (NLO) characterization of two novel copolymers containing alternating 3,4‐dialkoxythiophene and 1,4‐bis(1,3,4‐oxadiazolyl)benzene units. The copolymers were synthesized with a precursor polyhydrazide route. Both copolymers exhibited fluorescence around 430 nm under the irradiation of UV light. The NLO measurements were made with the single‐beam Z‐scan technique with Nd:YAG nanosecond laser pulses at 532 nm. The nonlinear refractive index of the investigated copolymers was negative, and the magnitude was as high as 10^?10 esu. The samples exhibited strong reverse saturation absorption and very good optical limiting properties at the wavelength used. The concentration dependence of third‐order NLO parameters was studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Synthesis of polyundecamethylene 2,6‐naphthalamide as semiaromatic polyamide‐containing naphthalene ring

A novel engineering plastic polyundecamethylene 2,6‐naphthalamide (PA11N) was prepared via a reaction of 2,6‐naphthalene dicarboxylic acid and 1,11‐undecanediamine through a three‐step procedure. The structure of synthesized PA11N was characterized by elemental analysis, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance (¹H‐NMR). The thermal behaviors were determined by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. The solubility, water‐absorbing capacity, and mechanical properties of PA11N have also been investigated. Melting temperature (T_m), glass transition temperature (T_g), and decomposition temperature (T_d) of PA11N are 294, 139, and 493°C, respectively. The results show that the heat resistance and mechanical properties of PA11N are near to those of polynonamethylene terephthalamide, and PA11N is a promising heat‐resistant and processable engineering plastic. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of photoluminescent conjugated polymer containing N‐(α‐naphthyl)‐carbazole unit

A novel luminescent conjugated polymer, poly[{9‐(α‐naphthyl)‐3,6‐divinylenecarbazolylene}‐alt‐co‐(1,4‐phenylene)] (PNVCP), bearing alternated 9‐(α‐naphthyl)‐carbazole and benzene units, was synthesized via a Wittig–Horner reaction. The solubility, thermal, and optical properties were investigated. It was soluble in common organic solvents, such as tetrahydrofuran and 1,2‐dichlororoethane. Thermogravimetric analysis and differential scanning calorimetry showed that the conjugated polymer exhibited good thermal stability up to 496°C with a glass‐transition temperature higher than 110°C. The photoluminescence properties were studied. The polymer emits blue light and the quantum yield is 93% in solution. The emission spectra exhibited an obvious solvent effect. With the increase of the polarity of the solvents, the fluorescence spectra changed obviously and appeared to be redshifted at room temperature. The redshift was more obvious in aromatic solvents than in aliphatic solvents. When N,N‐dimethylaniline was gradually added into the solution of the conjugated polymer, the emission intensity of the fluorescence decreased. In comparison, the emission intensity of the polymer showed invariability when 1,4‐dicyanobenzene was added into the polymer solution. Moreover, the fluorescence of the polymer could be effectively quenched by fullerene. Overall, the synthesized polymer is a potential candidate material for fabrication of polymeric light‐emitting devices. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 923–927, 2006     

Synthesis and characterization of novel biodegradable polymeric prodrugs containing 5‐fluorouracil and 4‐amino‐N‐(2‐pyrimidinyl) benzene sulfonamide terminal groups

To develop novel biodegradable polymeric prodrugs with target‐directing and drug‐active functional groups, a series of polymeric antitumor prodrugs containing sulfadiazine and 5‐fluorouracil terminal groups were prepared via the two‐step reaction of chlorinated poly(lactic acid) or chlorinated poly(lactic acid‐co‐glycolic acid) with potassium sulfadiazine (SF‐K) and 1,3‐dihydroxymethyl‐5‐fluorouracil. The synthesized polymers were characterized by means of infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, viscosity measurements, differential scanning calorimetry, and ultraviolet (UV) spectroscopy. The GA/LA value was varied, so that the effects of the comonomer content on the solubility, thermal properties, and degradable behaviors were examined respectively. It was found that introducing the GA units could increase the melting temperature (T_m), the hydrolytic degradation, and the hydrophilicity, while it decreased the glass transition temperature (T_g). The drug content of 5‐FU measured by UV spectra is 56.3 in maximum. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007