Anti-fouling ultrafiltration membrane prepared from polysulfone-graft-methyl acrylate copolymers by UV-induced grafting method

Membrane fouling is one of the most important challenges faced in membrane ultrafiltration operations. The copolymers of polysulfone-graft-methyl acrylate were synthesized by homogeneous photo-initiated graft copolymerization. The variables affecting the degree of grafting, such as the time of UV （Ultraviolet-visible） irradiation and the concentrations of the methyl acrylate and photoinitiator, were investigated. The graft copolymer membranes were prepared by the phase inversion method. The chemical and morphological changes were characterized by attenuated total reflection-Fourier transform infrared spectroscopy （ATR/FT-IR）, scanning electron microscopy, and water contact angles measurements. Results revealed that methyl acrylate groups were present on the membranes and the graft degree of methyl acrylate had remarkable effect on the performance of membranes. Pure water contact angle on the membrane surface decreases with the increase of methyl acrylate graft degree, which indicated that the hydrophilicity of graft copolymer membranes was improved. The permeation fluxes of pure water and bovine serum albumin solution were measured to evaluate the antifouling property of graft copolymer membranes, the results of which have shown an enhancement of antifouling property for graft copolymer membranes.

Synthesis and Characterization of the Polyacrylonitrile-block- poly(methyl acrylate) by RAFT Technique

Polyacrylonitrile-block-poly（methyl acrylate）（P（AN-b-MA）） was synthesized by reversible addition-fragmentation chain transfer （RAFT） polymerization employing macro-RAFT agent （PAN-RAFT） as the chain transfer agent and azobis（isobutyronitrile） （AIBN） as the initiator. A linear relationship between ln（[M]0/[M]1） and reaction time was observed. The molecular structure of P（AN-b-MA） was characterized by ^1H-NMR, element analysis, FTIR and SEC. The molecular weight distribution （MWD） was less than 1.40, the Mn could be controled from 0.733 to 4.834×10^4, and the molar content of MA in P（AN-b-MA） were from 15.6 to 75.0 percentage, respectively.

PHOTO-INDUCED DOPED POLYANILINE BY THE VINYLIDENE CHLORIDE AND METHYL ACRYLATE COPOLYMER AS PHOTO ACID GENERATOR

The emeraldine base form of polyaniline (PANI) can be doped by a photo-induced doping method. In this method a. copolymer of vinylidene chloride and methyl acrylate (VCMAC) was used as photo acid generator which can release proton when it is exposed to ultraviolet light (lambda = 254 nm). The structure of PANI-VCMAC system before and after irradiation was characterized by elemental analysis, IR, XTP, anti SEM images. Results obtained indicate that the photo-induced doping characteristics, such as doping position and type of charge carriers, are similar to that of PANI doped with HCl. The poor room-temperature conductivity (similar to 10-S-5/cm) of PANI-VCMAC system after irradiation may be due to low doping degree (similar to pH=3) and the difference in morphology as compared with PANI-HCl film.

Study of intermolecular interactions in binary mixtures of methyl acrylate with benzene and methyl substituted benzenes at different temperatures:An experimental and theoretical approach

The ultrasonic speeds,u and viscosities,ηof the binary mixtures of methyl acrylate with benzene,toluene,o-xylene,m-xylene,p-xylene,and mesitylene over the whole mole fraction range were measured at six different temperatures and at atmospheric pressure.From the experimental data,the excess isentropic compressibility,κ_(s)^(E),excess ultrasonic speed,u^(E),excess molar isentropic compressibility,K_(s,m)^(E),excess specific impedance,Z^(E)and deviations in viscosity,Δηhave been calculated.The partial molar isentropic compressions,K_(s,m,1) and K_(s,m,2),and excess partial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E) over the whole composition range,partial molar isentropic compressions,K_(s,m,1)^(-)and K_(s,m,2)^(-),and excesspartial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E)of the components at infinite dilution have also been calculated.The results specified the existence of weak interactions between unlike molecules,and these interactions follow the order:benzene>toluene>p-xylene>m-xylene>o-xylene>mesityle ne.The magnitude of interactions was found to be dependent on the number and position of the methyl groups in these aromatic hydrocarbons.

Polymerization of Methyl Acrylate with Nd-Al-α,α'-Dipyridyl Catalyst System

The polymerization of methyl acrylate (MA) with Nd(naph) 3 Al( i Bu) 3 α,α′ dipyridyl catalyst was studied. The molecular weight and its distribution were determined by gel penetration chromatography. Kinetic studies show that the MA polymerization rate is the first order with respect to monomer concentration. The apparent activation energy of MA polymerization is 49 34 kJ·mol -1 .

ESTIMATION OF REACTIVITY RATIOS OF METHYL ACRYLATE WITH N-ARYLMETHACRYL-AMIDE COPOLYMERS BY ~1H NMR METHOD

The copolymerizations of methyl acrylate （MA） with different N- arylmethacrylamide （N-ArMA） were carried out in benzene solution by free radical initiation. The compositions of the copolymers were deter mined by;H NMR method. The monomer reactivity ratios were calculated by the Fineman-Ross （F-R） method. The reactivity ratios and the activity of various N-ArMA with MA were investigated.

BARRIER PROPERTIES OF VINYLIDENE CHLORIDE/METHYL ACRYLATE COPOLYMER

A series of vinylidene dichloride (VDC) copolymers with methyl acrylate (MA) as comonomer (3-12wt%), was prepared by free-radical suspension copolymerization. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at 1.0 MPa and at 30 degrees C, and those to water vapor were measured at 30 degrees C and 100% relative humidity. All the VDC/MA copolymers studied are semicrystalline. As the MA content increases, the permeability coefficients of the copolymers to oxygen, carbon dioxide, and water vapor are progressively increased, caused by decrease in crystalline fraction and increase in free volume of VDC/MA copolymers.

Study of Catalysts on the Synthesis of Methyl Acrylate by Hydroesterification of Methyl Formate with Acetylene

The catalytic hydroesterification of methyl formate (MF) with acetylene to methyl acrylate (MA) over nickel-based catalysts prepared by impregnation has been comprehensively studied in a fixed bed reactor at 160 similar to 240 degrees C and under 4 similar to 6MPa GHSV: 630h(-1), CO:N-2:C2H2 = 65:28:7. In present work, we have found a catalyst of 11wt%NiO/Al2O3 (80 similar to 100 mesh) prepared by wet impregnation with NiCl2 aqueous solution, then calcined in air at 500 degrees C for 5 h. The selectivity to methyl acrylate and the conversion of methyl formate over 11wt%NiO/Al2O3 catalyst are higher than other catalysts studied in this paper. The optimum reaction temperature for the hydroesterification of methyl formate with acetylene to methyl acrylate is around 220 degrees C.

Cooperative catalytic effects between the penta-coordinated Al and Al_(2)O_(3)in Al_(2)O_(3)-AlPO_(4)for aldol condensation of methyl acetate with formaldehyde to methyl acrylate

The bare amorphous Al_(2)O_(3)-AlPO_(4)and Cs/Al_(2)O_(3)-AlPO_(4)catalysts were developed for the aldol condensation of methyl acetate with formaldehyde to methyl acrylate.The structure and property of catalyst were characterized by XRD,XPS,BET,Pyridine-IR,FT-IR,^(27)Al-MASNMR,NH_(3)-/CO_(2)-TPD and SEM.The correlation between structural features and acid-base properties was established,and the loading effect of the cesium species was investigated.Due to cooperative catalytic effects between the penta-coordinated Al and Al_(2)O_(3),the weak-Ⅱacid and medium acid site densities and the product selectivity were improved.While the basic site densities of these catalysts were almost in proportion to the conversion of methyl acetate.The loaded Cs could form new basic sites and change the distribution of acid sites which further enhance the catalytic performance.As a result,the 10Cs/8AlP was proved to be an optimal catalyst with the yield and selectivity of 21.2%and 85%for methyl acrylate respectively.During the reaction,a deactivation behavior was observed on 10Cs/8AlP catalyst due to the carbon deposition,however,it could be regenerated by thermal treatment in the air atmosphere at 400℃.

PHOTOSENSITIVITY OF CERIC ION INITIATED METHYL ACRYLATE POLYMERIZATION

The polymerization of methyl acrylate was sensitive to UV light. Under UV light,the rate of polymerization is 8 times as high as the rate in dark.The overall activation energy was decreased by the UV light (313nm).A tentative explanation is given and the mechanism is discussed.

STUDIES ON THE HYDROGENATION OF METHYL ACRYLATE CATALYZED BY Pd/DVB CROSSLINKED POLY-(N-VINYL PYRROLIDONE)

Many kinds of dispersed Pd (0) supported on cross-linked poly (N-vinyl pyrrolidone) were prepared and characterized by IR and X-ray diffraction. Their hydrogenation properties of methyl acrylate have been examined. Experimental results indicate that the hydrogenation rate will reach a maximum as the degree of crosslinking increases to a certain point. The catalytic activity of the catalysts is closely related to the preparation condition and the particle size of Pd of the catalysts. Some other factors which affect the catalytic properties have also been studied.

COMPUTER SIMULATIONS ON UNPERTURBED CONFIGURATIONAL DIMENSIONS OF POLY (METHYL ACRYLATE)

A full-relaxation optimization of molecule and the popular MM2 force field are employed to obtain the geometry parameters and the conformational energy surface of a meso or a racemic dyad of poly(methyl acrylate) (PMA) with a specified carbonyl-bond orientation in side-groups. It is found that the conformational energy maps calculated here considerably differ from those calculated with the rigid molecular model as reported in the earlier studies. The g(-) state cannot be omitted in the obtained contour maps. Two important conformers tg(-) and g(-t) with energy minima were newly detected for a racemic dyad. The analysis on the conformations with energy minima confirmed that the ester groups are not always perpendicular to the plane defined by the two adjacent skeletal bonds and may change their relative orientations to meet the requirement of lower energies during the conformational state transition. Instead of the early way of adjusting the interaction energy parameters to fit the experimental data, we attempt to predict unperturbed chain dimensions via the reliable force field and the configurational statistical mechanics. The proposed scheme with three rotational states identified from the contour maps allowed us to satisfactorily reproduce the experimental dimensions of random PMA chains.

PHOTOSENSITIVITY OF Ce (Ⅳ) INITIATED METHYL ACRYLATE POLYMERIZATION

The influences of UV light irradiation (313 nm) and diffused daylight on the polymerization of methyl acrylate initiated by the ceric ammonium nitrate without any reducing agent have been studied both in aqueous nitric acid and in pure water. The rate of polymerization was found to be accelerated and the overall activation energy and the induction time were found to be decreased sharply by the UV light irradiation. Under UV light, the rate of polymerization is 8 times as high as the rate in dark. The rate of polymerization was found to attain a maximum with the increase of nitric acid concentration and the rate of polymerization became less sensitive to UV light in the presence of nitric acid whereas the induction period reduced outstandingly. Based on the experimental results, the mechanism is proposed.

Studies on the Graft Copolymerization of Methyl Acrylate and Ethyl Acrylate onto Corn Starch Using Potassium Persulfate-Sodium Thiosulphatc as Initiation System

Grafting copolymerizations of methyl acrylate(MA) and ethyl acrylate(EA) onto corn starch, respectively, initiated by potassium persulfate-sodium thiosulphate (KPS-STS) redox system, were studied. The structures of poly(MA)-g-starch and poly(EA)-g-starch were characterized by IR, SEM and X-ray diffraction. Experimental results show that KPS-STS is an efficient initiation system for grafting of MA and EA onto corn starch. The maximum percent grafting was obtained at [KPS] of 6.0× 10~3 mol/L, [STS] of 1.8× 10 5 mol/L, [M] of 6. 0× 101 mol/L, S:L=4:100 at 40℃ for 6 h. The reactivity order is MA>EA.

CARBONACEOUS PRODUCTS OF POLYMER-PALLADIUM COMPLEXES AS CATALYSTS FOR THE HYDROGENATION OF METHYL ACRYLATE

Many catalysts were pcrpared by carbonization of ion exchange resin-PdCl_2 complexes at high temperature in nitrogen, hydrogen atmosphere. The rates for the hydrogenation of methyl acrylate and the amounts of Pd elution of the carbonaceous products were measured and compared with those of commercial Pd/C catalyst. It indicates that the carbonaceous products are less active than Pd/C. However, the leaching of Pd from carbonaceous products is very small and much less than that from Pd/C.

Synthesis and Crystal Structure of (Z)-Methyl-3-methoxy-2-{2-[(4-(E-3-p-tolylacryloyl)phenoxy)methyl]phenyl}acrylate

The title compound,(Z)-methyl-3-methoxy-2-{2-[(4-(E-3-p-tolylacryloyl)phenoxy)-methyl]phenyl}acrylate,was synthesized and determined by X-ray single-crystal diffraction.The crystal belongs to the triclinic system,space group P1 with a=8.0157(8),b=12.5748(13),c=13.3768(14)Å,α=64.770(2),β=75.720(2),γ=89.784(2)°,μ=0.085 mm^(-1),Mr=442.49,V=1174.1(2)Å3,Z=2,Dc=1.252 g/cm^(3),F(000)=468,T=294(2)K,R=0.0603 and wR=0.1498 for 2644 observed reflections with I〉2σ(I).X-ray diffraction analysis reveals that the single crystal contains strong non-classical hydrogen bonds.The preliminary bioassay showed that the title compound exhibits inhibitory activity against the Pseudoperoniospora cubensis and Rhizoctonia solani at the test concentration of 200 mg/L.

EFFECTS OF ω-ACRYLOYL POLY (ETHYLENE OXIDE) MACROMONOMER ON EMULSIFIER-FREE EMULSI0N COPOLYMERIZATION OF METHYL METHACRYLATE AND n-BUTYL ACRYLATE

Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction termi-nating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emul-sion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containingvarious concentrations of PEO-A was studied. In all cases stable emulsion coplymerizationsof MMA and BA were obtained. The stabilizing effect was found to be dependent on themolecular weight and the feed amount of the macromonomer.

KNaY-zeolite catalyzed dehydration of methyl lactate

A promising catalyst, KNaY was prepared by an ion exchange method with aqueous potassium chloride solution, Compared with NaY, KNaY was an effective catalyst for the dehydration of methyl lactate to methyl acrylate. Under the optimized conditions, an improved yield of 37.9 mol% was achieved.

BARRIER PROPERTY AND STRUCTURE OF ACRYLONITRILE/ACRYLIC COPOLYMERS

A series of acrylonitrile (AN) copolymers with methyl acrylate (MA) or ethyl acrylate (EA) as comonomer (5-23 wt%) was prepared by free-radical copolymerisation. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at 1.0 MPa and at 30 degrees C, and those to water vapor also measured at 100% relative humidity and at 30 degrees C. All the AN/acrylic copolymers are semicrystalline. As the acrylate content increase, the permeability coefficients of the copolymers to oxygen and carbon dioxide are increased progressively, but those to water vapor are decreased progressively. The gas permeability coefficients of the polymers were correlated with free-volume fractions or the ratio of free volume to cohesive energy.

Miscibility and Crystallization of PHB/PMA Blends

The miscibility, crystallization behavior and morphological structure of PHB/PMA blends have been studied by the differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The chemical repeat units of the two components of the blend are isomers. The results indicate that PHB and PMA are miscible in the melt. The addition of PMA into PHB results in a depression in the spherulite growth rate of PHB. With increasing PMA content in the blends, the texture of PHB spherulite becomes more open.