Removal of manganese from waste water by complexation-ultrafiltration using copolymer of maleic acid and acrylic acid

Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.

Synthesis and Characteristic Study on Complexes of Europium(Ⅲ) and Maleic Acid Doped with Non-Fluorescent Ions

Complex of europium （Ⅲ） with maleic acid, and binuclear complexes of europium（Ⅲ）with maleic acid doped with non-fluorescent ions gadolinium, lanthanum and yttrium, were synthesized. The compositions and structures of complexes were characterized with elemental analysis, single crystal X-ray diffraction, IR and DSC-TG. Fluorescent properties were studied with fluorescence spectrum. The results indicated that the strongest fluorescent complexes were obtained when the ratio of europium and non-fluorescent ion was 8：2. The order of Eu^3＋ fluorescence strengthened by three doped rare earths was Gd^3＋ 〉La^3＋ 〉Y^3＋

Microwave-assisted Polymerization of ε-Caprolactone with Maleic Acid as Initiator and Drug Release Behavior of Ibuprofen-Poly(ε-caprolactone) System

Poly(e-caprolactone) (PCL) with weight-average molar mass over 10000 g/mol was synthesized by microwave-assisted ring-opening polymerization of e-caprolactone (e-CL) with maleic acid (MA) as initiator (2.45 GHz, 360 W, 85 min). Ibuprofen-PCL controlled release system was prepared directly by the ROP of e-CL in its mixture with ibuprofen. The release of ibuprofen from the system was sustained and steady.

Synthesis of Coordination Polymers Using Different Maleic Acid Ligands under Hydrothermal Conditions

A novel coordination polymer, [ Ni （mal） （1,10＇-phen） （ H2O） ] n （ 1 ） （ mal = malate, 1,10＇-phen = 1,10- phenanthroline） was synthesized using malic acid which was generated from maleic acid via hydrothermal reaction. Complex 1, which displays a two-dimensional supramolecular network, was formed by the addition reaction of Ni and maleic acid with water molecules. To our knowledge, several coordination polymers have been directly synthesized from malic acid, but these types of complexes have seldom been synthesized from maleic acid via hydrothermal reactions. When Ni（ Ⅱ ） ion was changed to Zn（ Ⅱ） ion under the same condition, two-dimensional covalent complex 2 [ Zn2 （fma） 2 （1,10＇-phen） 2 ] n （fma = fumatic acid） was formed. Furthermore, complex 2 exhibits intense photolumi- nescent property at room temperature.

A STUDY OF SILICA-SUPPORTED CROSS-LINKED POLY (MALEIC ACID-CO-STYRENE)-PLATINUM COMPLEX IN THE HYDROGENATION OF p-CRESOL

A silica-supported cross-linked poly(maleic acid -co- styrene)-platinum complex (PMS-Pt) has been prepared and found to be active in the hydrogenation of p-cresol under mild conditions (303-323K, 1.01 x 10(5)Pa). In this hydrogenation system water serves as a solvent and p-cresol can be converted to 4-methylcyclohexanol quantitatively via 4-methylcyclohexanone as intermediate.

Covalent Immobilization of Lipase on Poly(acrylonitrile-co-maleic acid) Ultrafiltration Hollow Fiber Membrane

Lipase from Candida rugosa was covalently immobilized on the surface of an uhrafihration hollow fiber membrane fabricated from poly （ acrylonitrile-co-maleic acid） （ PANCMA ） in which the carboxyl groups were activated with 1-ethyl-3-（ dimethylaminopropyl ） carbodiimide hydrochloride （ EDC ） and dicyclohexyl carbodiimide （ DCC ）/ N-hydroxyl succinimide（NHS）, respectively. The properties of the immobilized lipase were assayed and compared with those of the free enzyme. The maximum activities were observed in a relatively broader pH value range at high temperatures for the immobilized lipase compared to the free one. It was also found that the thermal and pH stabilities of lipase were improved upon immobilization and at 50 ℃ the thermal inactivation rate constant values are 2. 1 × 10^ -2 for the free lipase, 3.2 × 10^-3 for the immobilized lipase on the EDC-activated PANCMA membrane and 3.5 × 10^-3 for the immobilized lipase on the DCC/NHS-activated PANCMA membrane, respectively.

COPOLYMERS OF 2-ACRYLAMIDO-2-METHYL-1-PROPANESULFONIC ACID/MALEIC ACID:SYNTHESIS,CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY

2-Acrylamido-2-methyl-1-propanesulfonic acid （AMPS）, and maleic acid （MA） copolymerized with different feed ratios using N,N-dimethylformamide as a solvent and benzoyl peroxide （Bz2O2） as an initiator at 70℃. Structure and composition of copolymers for a wide range of monomer feed were determined by elemental analysis （content of N for AMPS-units）. Monomer reactivity ratios for AMPS （M1）-MA （M2） pair were determined by the application of conventional linearization methods such as Fineman-Ross （F-R）, Kelen-Tudos（KT） and Extended Kelen-Tudos （EKT） and a nonlinear error invariable model method using a computer program RREVM. The characterizations were done by Fourier transform infrared spectroscopy （FTIR）, differential scanning calorimetry （DSC） thermal gravimetry analysis （TGA）, and and X-ray diffraction. The antimicrobial effects of polymers were also tested on various bacteria, and yeast.

Graft co-polymerization of maleic acid and vinyl acetate onto poly(vinylidene fluoride) powder by pre-irradiation technique

Binary monomers of maleic acid and vinyl acetate are grafted onto poly(vinylidene fluoride) (PVDF) powder by pre-irradiation induced graft polymerization technique in emulsion solution. The co-grafting of binary monomers is successfully proved by FT-IR spectroscopy analysis. The influences of the absorbed dose, reaction temperature, reaction time, total concentration of monomers, and feed ratio of binary monomers on the degree of grafting are investigated. The thermal property of grafted PVDF powder was characterized by differential scanning calorimetry (DSC) and thermo-gravimetry analysis (TGA).

Kinetics of Maleic Acid/Itaconic Acid In-situ Polymerization on Cotton

Cotton fabric samples are padded with maleic acid (MA) and itaconic acid (IA) finishing bath in the presence of potassium persulfate (K 2S 2O 8), and then dried at different temperatures for different time intervals. The portion of unreacted monomers on cotton fabric samples is determined by means of measuring the double bond content. The kinetic data (rate constants, Arrhenius activation energy, frequency factor) of the in-situ polymerization have been calculated.

Investigation of the Reaction Mechanism of Itaconic Acid/Maleic Acid Copolymer System and Cotton Cellulose

The reaction mechanism of IA/MA copolymer system andcotton cellulose is conjectured and verified, the two keysteps, such as the formation of cyclic anhydride interme-diates and the building of ester crosslinklng, and the ef-fect of sodium hypophosphite are especially emphasized,by FT - IR spectroscopy and acid- base titration anal-yses. The experiments reveal that carboxylic acids main.ly change to cyclic anhydride in the pre - drying step andSodium Hypophosphite (SHP) has effect on it, but mostester - crosslinkages are built in the curing step and SHPhas effects on both anhydride formation and ester -crosslinking formation.

Constructing osteo-inductive bio-ink for 3D printing through hybridization of gelatin with maleic acid modified bacterial cellulose by regulating addition volumes of maleic acid solution

Bacterial cellulose(BC)is an exopolysaccharide with unique properties that has been applied in various fields.However,the dense and intertwined nature of BC fibers limits its use in certain applications,including 3D printing scaffolds for bone regeneration.In this work,a controllable BC-based bio-ink for 3D printing was successfully prepared by modifying the neat BC through maleic acid(MA)treatment,aiming to promote bone tissue regeneration.To achieve homogeneous BC dispersions while preserving its crystalline and chemical properties,BC was modified by MA solution(60%,w/V)with solid-liquid ratio from 1꞉5 to 1꞉50(w/V)to obtain MA-BC dispersions.The analysis results from microstructure,chemical group,crystallinity,and wettability indicated that the BC/MA solution with ratio of 1꞉30 demonstrated the best pre-treatment performance to obtain MA-BC.Subsequently,by combining MA-BC with gelatin,we successfully formulated MA-BC-GEL gels with favorable rheological properties and compression modulus,which can be used as promising bio-inks for 3D bioprinting applications.In vitro tests demonstrated 1꞉30 MA-BC possessed excellent biocompatibility,a significant ability to express the alkaline phosphatase gene and osteogenic-related genes,and facilitated the formation of mineralized nodules.The utilization of this novel bio-ink in scaffold preparation for bone regeneration highlights the promising application of modified BC in bone tissue engineering field.

Maleic acid and malonic acid reduced the pathogenicity of Sclerotinia sclerotiorum by inhibiting mycelial growth,sclerotia formation and virulence factors

Sclerotinia sclerotiorum is a necrotrophic plant pathogenic fungus with broad distribution and host range.Bioactive compounds derived from plant extracts have been proven to be effective in controlling S.sclerotiorum.In this study,the mycelial growth of S.sclerotiorum was effectively inhibited by maleic acid,malonic acid,and their combination at a concentration of 2 mg/mL,with respective inhibition rates of 32.5%,9.98%,and 67.6%.The treatment of detached leaves with the two acids resulted in a decrease in lesion diameters.Interestingly,maleic acid and malonic acid decreased the number of sclerotia while simultaneously increasing their weight.The two acids also disrupted the cell structure of sclerotia,leading to sheet-like electron-thin regions.On a molecular level,maleic acid reduced oxalic acid secretion,upregulated the expression of Ss-Odc2 and downregulated CWDE10,Ss-Bi1 and Ss-Ggt1.Differently,malonic acid downregulated CWDE2 and Ss-Odc1.These findings verified that maleic acid and malonic acid could effectively inhibit S.sclerotiorum,providing promising evidence for the development of an environmentally friendly biocontrol agent.

Equilibrium of Extraction of Succinic, Malic, Maleic and Fumaric Acids with Trioctylamine

Extraction equilibrium features of succinic acid, malic acid,maleic acid and fumaric acid were investi- gated systematically withtrioctylamine (TOA) in chloroform, 4-methyl-2-pentanone (MIBK) and1-octanol. Fourier transform-infrared (FTIR) spectroscopic analysisof organic samples loaded with the acid shows that amine forms 1:1complex of ion-pair association with succinic acid, malic acid andmaleic acid, and 1:1, 2:1 complex of ion-pair association withfumaric acid. It is proposed that the complex forms depend on thesecond dissociation constant of the dibasic acid, pK_a2.

Crosslinking of PVA Pervaporation Membrane by Maleic Acid

Maleic acid (MA) crosslinked polyvinyl alcohol (PVA) membrane is prepared using a high temperature esterification reaction between PVA and MA in the presence of sulfuric acid as a catalyst. The crosslinking reaction mechanism is investigated using FT IR spectral analysis. The results indicate that maleic acid reacts with hydroxyl groups in PVA to form mono and bis ester in a two step process.

Oxidation of furfural to maleic acid and fumaric acid in deep eutectic solvent(DES)under vanadium pentoxide catalysis

Furfural is an alternative feedstock and has been used for the production of maleic acid(MA)and fumaric acid(FA)by an oxidation process.Deep eutectic solvents(DESs)were used as the green solvents while sodium chlorate was used as an oxidant and vanadium pentoxide was used as the catalyst at 70-90°C under atmospheric pressure.It was found that several acidic DESs are valid,such as acetic acid/choline chloride(AA/ChCl)and propionic acid/choline chloride(PA/ChCl),and AA/ChCl DES was selected as the solvent for the conversion.The optimal DES is AA/ChCl,and the effect of the amount of oxidant,time,and temperature on the yield of the MA and FA has been systematically studied,and the conversion of furfural can reach 100%while the yield of the MA and FA reached 66.5%under reaction temperature of 80℃ for 12 h,which provides a new green route to synthesis valuable monomers from furfural.

The UV Aging Properties of Maleic Anhydride Esterified Starch/Polylactic Acid Composites

Esterified starch/polylactic acid（ES/PLA） blending composite was prepared by melting extrusion with maleic anhydride esterified starch and PLA as the raw materials. The composite was accelerated aging by using UV aging box, and its properties were characterized by Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM）, X-ray diffraction（XRD）, thermo gravimetric analysis（TGA） and mechanical testing machine. FT-IR and SEM results show that the infrared absorption peak intensities of C-O, C-H, and C=O in aged samples decrease gradually with increasing aging time. The damage degree of surface and internal of aged samples increases gradually. XRD analysis results show that after aging treatment, the crystalline diffraction peak of thermoplastic esterified starch at 2θ = 21° disappears and the diffraction peaks of PLA at 2θ = 16.5° appear, indicating that the hydrolysis rate of esterified starch is greater than that of PLA. The crystallinity of PLA in aged sample shows an increasing trend at first followed by a decreasing one along with the increasing time of aging treatment, suggesting that the hydrolysis of amorphous regions of PLA is more preferential than its crystalline regions. Because of the influence of crystal structure and the change of composition structure, the initial decomposition temperature of aging test specimen gradually increases with the extension of aging time. The maximum decomposition rate temperature and residual mass increases at first, and then decrease after the aging time extending to 1600 h. As the aging time increases, the damage degree of combination interface between esterification starch and PLA is exacerbated, resulting in the tensile strength and bending strength of aged specimen decreasing gradually.

接枝不同种类氨基酸对聚天冬氨酸阻垢剂阻垢性能的影响

在油田生产过程中结垢问题给油田企业带来巨大损失。常见的处理结垢的方法大致分为物理法、工具法和化学法。采用物理法、工具法处理结垢问题存在费用高、垢物清除效率低等缺陷,化学法因其操作简单、用量少、效果好等优点而被广泛采用。近年来,随着人们对环境保护意识的增强,聚天冬氨酸类阻垢剂被广泛研究。以马来酸酐和碳酸铵为原料合成了聚琥珀亚酰胺(PSI),在此基础上接枝丝氨酸、谷氨酸、酪氨酸并研究其阻垢性能。结果表明:谷氨酸接枝改性聚合物(GUL-PASP)阻垢效率为100%,具有优异的阻垢性能。

光引发聚合制备P(AA-MA)高吸水性树脂及性能研究

以丙烯酸(AA)、马来酸酐(MA)为聚合单体,亚甲基双丙烯酰胺(MBA)为交联剂,安息香异丙醚为光引发剂,采用紫外光辐射聚合法合成了P(AA-MA)高吸水树脂。讨论了AA中和度、MA氨化度、单体质量比、交联剂的使用量等因素对吸水树脂吸水性能的影响。通过红外光谱(FT-IR)、扫描电子显微镜(SEM)和热重分析(TG)对树脂的分子结构、微观形貌和热稳定性进行了表征。结果表明,优化实验条件下所制备的高吸水树脂在蒸馏水中的最大吸水倍率为1112.5g/g,在0.9%盐水中的最大吸水倍率为100.8g/g。

复合功能型聚羧酸减水剂的制备及其性能研究

以改性聚醚异戊烯醇聚氧乙烯醚(TPEG-2400)为功能大单体,甲基丙烯酰氧乙基三甲基氯化铵(DMC)、丙烯酸(AA)和顺丁烯二酸酐(MA)为功能小单体,以过氧化氢(H_(2)O_(2))-抗坏血酸(Vc)氧化还原体系为引发剂,以巯基丙酸(MPA)为链转移剂,通过水溶液自由基聚合法,制备一种兼具抗泥、保坍性能的复合功能型聚羧酸减水剂。通过正交实验设计得出最佳合成条件,并通过单因素实验优化合成条件。通过FTIR、TGA、TOC进行性能表征。结果表明,最佳合成工艺条件:反应温度为45℃,n(AA)∶n(TPEG)=4.0∶1,n(DMC)∶n(TPEG)=0.75∶1,n(MA)∶n(TPEG)=0.6∶1,巯基丙酸(MPA)用量为大单体聚醚的0.65%,引发剂用量为大单体聚醚的1.27%,且m(H_(2)O_(2))∶m(Vc)=3.5∶1,A液、B液滴加时间为3.0,3.5 h。此合成工艺条件下,得到的复合功能型聚羧酸减水剂分散性能较好,对蒙脱土的敏感性较低且经时坍落度损失较小。

改性淀粉与聚乳酸共混物的结构与性能

可生物降解的聚乳酸(PLA)可用于替代化石燃料基聚合物,可再生淀粉改性PLA有利于其推广应用。采用湿法工艺制备了3种马来酸酐(MAH)改性玉米淀粉(CSM),与PLA共混制备了PLA/CSM的共混物,对改性淀粉和PLA与不同淀粉的共混物进行了结构与性能研究。红外分析表明,MAH可通过酯化接枝至淀粉上,MAH水溶液滴入淀粉水分散液中的淀粉酯化程度高于MAH直接加入淀粉水分散液接枝而得的,冷冻干燥得到的MAH改性淀粉由粒度仪测得的粒径小于热干燥的改性淀粉。差示扫描量热分析(DSC)和X射线衍射(XRD)分析表明,PLA中混入淀粉后易于结晶,结晶度也提高了,冷冻干燥的改性淀粉与PLA共混膜的结晶度高于热干燥改性淀粉共混的PLA膜,玻璃化转变温度有所下降,但仍高于52℃;扫描电镜(SEM)可观察到改性淀粉与PLA共混有较好的界面相容性,热失重分析(TG)表明PLA与改性淀粉共混后热稳定性降低,但5%热失重温度仍高于220℃,600℃残炭率有3%以上。湿法工艺可用于淀粉接枝MAH,改性后淀粉可用于PLA的共混改性以降低成本。