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.

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.

Synthesis and Characterization of a Novel Biomaterial: Maleic Anhydride-modified Poly(dl-lactic acid)

A novel modified poly(dl-lactic acid) (PDLLA) was obtained by covalently grafting of maleic anhydride onto the backbone of PDLLA, attempting to improve PDLLA’s hydrophilicity and cell affinity and to provide reactive groups for further chemical modification. FTIR, 13C NMR and DSC were used to characterize the maleic anhydride-modified PDLLA.

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。

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＋

Flavonoids and Amino Acids Analysis of the Fruits of Cornus mas L. Introduced in Uzbekistan

Cornelian cherry is used in the food and pharmaceutical industry as an ornament, in traditional medicine, and in the manufacture of household items. It is widely used in medicine for the prevention and treatment of many diseases. Therefore, it is important to research the chemical composition of these species. In the article, based on our research, the analysis of the quantitative calculation of flavonoids and amino acids of the fruits of the “Elegant” and “Svetlyachok” cherry varieties was carried out. It was found that the amount of amino acids in the fruits of Cornus mas L., introduced in Uzbekistan, is higher in the variety “Svetlyachok” 2.643235 mg/g. In “Elegant” variety it was 1.794235 mg/g. The amount of 4 different flavonoids in the fruit was also determined. It has been established that the Elegant variety has a high concentration of lutein and rutin, and the svetlyachok has a high concentration of apigenin and quercetin.

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.

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.

TPAS/PLA/PLA-g-MAH共混材料制备及性能

使用熔融和注塑工艺制备热塑性醋酸淀粉(TPAS)/聚乳酸(PLA)/聚乳酸接枝马来酸酐(PLA-g-MAH)共混材料,考察PLA-g-MAH的增容效果,并对共混材料的力学性能、热性能、熔体流变性能和亲水性进行分析。结果表明:PLA-g-MAH提高TPAS在PLA中的分散程度,显著增强了两者的界面结合力;随着PLA-g-MAH含量的增加,共混材料的拉伸强度、断裂伸长率和缺口冲击强度均先升高后降低,含量为15%时达到最大值,较未增容体系分别增加17.9%、18.5%和138.5%;添加PLA-g-MAH导致共混材料结晶能力减弱,表面疏水性提高,共混材料熔体黏弹性增强,加工性能提高。

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.

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.

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.

The Effect of Methacrylic Acid and Maleic Acid on the Isothermal Kinetics of Acrylic Acid Crosslinking Co-polymerization under Conventional and Microwave heating

The kinetics of free-radical crosslinking co-polymerization(FRCCP)of acrylic acid(AA)with both methacrylic acid(MA)(PAMA hydrogel)and maleic acid(MAL)(PAMAL hydrogel)was investigated under the conditions of isothermal conventional heating(CH)and under the conditions of microwave heating(MWH)with controlled cooling.The kinetics curves of FRCCP of PAMA and PAMAL hydrogels under the conditions of CH are described with the kinetics model of second order chemical reaction,whereas the kinetics curves under the conditions of CH are described with the kinetics model of Polany-Winger.It is proved that MWH leads to the changes in the rate of FRCCP and to the changes in the values of the kinetic parameters activation energy(Ea)and pre-exponential factor(lnA).It was found the existence of relationship between the values of the kinetic parameters calculated for MWH and CH for PAMA and PAMAL hydrogel synthesis process,which is well-known as compensation effect.The effect of MWH on the kinetics of FRCCP for PAMA and PAMAL hydrogel formation were explained by applying the model of activation by selective energy transfer(SET).The changes in kinetics model,rate of FRCCP and kinetics parameters,caused with the MWH can found wide application in designing novel technologies for obtaining polymers and for synthesis of polymers with novel physico-chemical properties.The suggested mechanism of activation for polymerisation under the conditions of MWH also enables development of novel reaction systems and technologies for polymers productions.

LLDPE-g-MAH接枝率的测定方法的建立与分析

本文通过酸碱滴定法和红外分析法建立了一种快速检测线型低密度聚乙烯接枝马来酸酐(LLDPE-g-MAH)接枝率的方法。首先,通过酸碱滴定法得到不同接枝率LLDPE-g-MAH样品的接枝率,然后通过红外分析法得到该样品的马来酸酐特征峰与LLDPE内标峰的峰高比值,通过滴定法得到的接枝率与红外特征峰峰高比值的拟合出标准曲线。该标准曲线可以用于快速测定未知LLDPE-g-MAH的接枝率。此方法操作快速便捷,对工业投产具有指导意义。

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.

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.

PHOTOCOPOLYMERIZATION OF MALEIC ANHYDRIDE AND VINYL ACETATE IN TETRAHYDROFURAN~*

The copolymerization of maleic anhydride and vinyl acetate in tetrahydrofuran was studied. Results show that the maximum copolymerization rate is in 0.6 mole fraction of maleic anhydride, indicating the involvement of maleic anhydride-tetrahydrofuran charge transfer complex in the chain initiation process. ESR study provides collateral evidence for the formation of maleic anhydride radical and tetrahydrofuran radical.