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.

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.

SYNTHESIS AND THERMAL PROPERTIES OF A NEW CHOLIC ACIDCONTAINING COPOLYMER

A new copolymer was synthesized by free radical polymerization in solution from methyl 3α-methylacryloyl-7α, 12α-dihydroxy-5β-cholan-24-oate (MACAME) and maleic anhydride (MAN). The copolymer was characterized by FT-IR and functional group analysis. The reactivity ratios of the two monomers were estimated [r_1 = 11.6 (MACAME), r_2 = 0.01(MAN)] by conducting a series of copolymerizations with a variety of monomer feed compositions and analyzing thecopolymer composition. Thermogravimetric and differential scanning calorimetric analyses of the samples indicate that thecopolymer possesses good thermal stability. The temperature at which the copolymer samples experienced a 10% weight loss(T_(WL)) is over 287℃, and the T_g ranged from 174 to 185℃ for the copolymers.

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.

Synthesis and application of lignin-based copolymer LSAA on controlling non-point source pollution resulted from surface runoff

In this article,alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin,starch, acrylamide,and acrylic acid).Its practical application effect and environmental safety were studied.The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants.The runoff quantity was decreased by 16.67%-47.00%and the loads of total suspended solids (TSS),chemical oxygen demand (COD),total nit...

Comparison of selective flocculation of low grade goethitic iron ore fines using natural and synthetic polymers and a graft copolymer

This study aims to beneficiate low grade goethitic iron ore fines using a selective flocculation process. Selective flocculation studies were conducted using different polymers such as starch amylopectin(AP), poly acrylic acid(PAA), and a graft copolymer(AP-g-PAA). The obtained results were analyzed; they indicate the enhancement of the iron ore grade from 58.49% to 67.52% using AP-g-PAA with a recovery of 95.08%. In addition, 64.45% Fe with a recovery of 88.79% was obtained using AP. Similarly, using PAA, the grade increased to 63.46% Fe with a recovery of 82.10%. The findings are also supported by characterizing concentrates using X-ray diffraction(XRD) and electron probe microanalysis(EPMA) techniques.

An Approach to the Flame Retardancy of EVA Copolymer by Plasma Treatmentc2

An attempt was made in the paper aiming at imparting flame retardancy to polymers by plasma grafting technique Based on EVA copolymers with different VA contents the author tried to use the Ar plasma followed by grafting with/without subsequent saponification and metal ion exchange expediting the charring of polymers upon heationg Characterization of the flammability of the plasma treated EVA copolymers grafted with acrylic monomers(MAA,AA and AAm)indicates that this approach turns out to be a promising way and worthy doing whatever in research and/or applications

Synthesis and characterization of amphiphilc block copolymer poly(methyl acrylic acid)-block-polytetrahydrofuran

Under the specially designated condition the polymerization of both tetrahydrofuran (THF) and tert-butyl methacrylate (tBMA) is a living one. The diblock copolymer, poly(tert-butyl methacrylate)-block-polytetrahydrofuran (PtBMA-b-PTHF), was successfully synthesized by meansof the coupling reaction of living cationic PTHF+, SbF6 with living anionic PtBMA-, Li+. LiCI, whichhas a beneficial effect on the molecular weight distribution (MWD) in the anionic polymerization of (meth)acrylates, hinders the coupling reaction of living chains and cannot be used in the preparation of tBMA precursor. The hydrolysis of the aforementioned diblock copolymer under acid condition results in the amphiphilic diblock copolymer, i.e. poly(methyl acrylic acid)-block-polytetra-hydrofuran (PMAA-b-PTHF). The diblock copolymers were characterized with GPC and IR.

Effect of the Side Chain Structure on Hydrolysis Degradation of Zinc Acrylate Copolymers

In this report,zinc acrylate copolymers were synthesized by used different organic acid as the side chain structure.These copolymers were further characterized by GPC,DSC and Water absorption analysis respectively,and then the effects of the chain structure of organic acid on hydrolysis degradation and copper release rate were also discussed.In the meantime,the result shows that the biocide release rate could be controlled by used different chain structure of organic acid.

3D打印工艺参数对PLA/PTW共混物力学性能影响的研究

采用3D打印中的熔融沉积成型(FDM)工艺制备了聚乳酸/乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PLA/PTW),通过单因素实验探究了3D打印工艺参数(喷头温度、打印平台温度和打印速度)对PLA/PTW共混物力学性能的影响,并在此基础上设计了三因素三水平正交实验,优化了3D打印的工艺参数。结果表明,共混物的冲击强度和拉伸强度均随喷头温度的增加呈现先上升后下降、均随打印平台温度的增加而增加、均随打印速度的增加出现下降的趋势。各工艺参数对PLA/PTW共混物综合力学性能的影响从大到小依次为:喷头温度、打印速度、打印平台温度,且当喷头温度为210℃、打印平台温度为80℃以及打印速度为40 mm/s时,打印出的PLA/PTW共混物的综合力学性能最佳。

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。

乙烯-丙烯酸及酯共聚物的结构研究

为进一步探究自由基聚合与配位共聚得到乙烯-丙烯酸甲酯共聚物的支链结构差异,并对该支链结构差异性的本质原因进行解释,本研究对进口的乙烯-丙烯酸及酯共聚物的熔点、熔指、分子量、极性单体插入率以及共聚物的微观链结构进行表征分析。研究结果表明:(1)乙烯-丙烯酸及酯共聚物熔点范围为64.1~98.4℃,熔融指数范围为2.81~10.50 g/10 min。EMA、EEA、EBA的重均分子量(Mw)都在20万左右,分子量分布(M_(w)/M_(n))小于5.0。(2)EMA共聚物中极性单体MA是以支链末端和主链两种形式并存于聚乙烯链上,其中以支链末端为主。MA在聚乙烯链中没有连续插入结构,MA主要以无规形式插入聚乙烯中。(3)进口的EMA共聚物是通过高温高压自由基聚合得到,EMA共聚物链中含有丁基、戊基以及长支链,而配位聚合得到的EMA共聚物含有甲基、乙基、丙基等短支链以及长支链。两种聚合方式得到EMA聚合物的微观链结构存在明显差异。

超韧聚乳酸/乙烯丙烯酸丁酯甲基丙烯酸缩水甘油酯共混物的制备与性能

向聚乳酸(PLA)和乙烯丙烯酸丁酯甲基丙烯酸缩水甘油酯(EBA-GMA)接枝共聚物的共混物PLA/EBA-GMA(质量比,70/30)中引入催化剂(N,N-二甲基十八胺,DMSA),通过促进PLA与EBA-GMA的原位反应增容来提高共混体系的冲击韧性,并研究了DMSA质量分数对共混体系力学性能的影响。结果显示,未添加DMSA时,PLA/EBA-GMA(70/30)共混物的冲击强度仅为10.9 kJ/m^(2)。当DMSA质量分数为0.5%时,PLA/EBA-GMA(70/30)共混物的冲击强度高达63.1 kJ/m^(2)。共混物结构与形态表征结果表明,添加少量DMSA就能有效促进EBA-GMA上环氧基团与聚乳酸端基的反应活性,提高PLA/EBA-GMA共混物的冲击韧性。

乙烯-丙烯酸共聚物改性环氧树脂/UHMWPE纤维复合材料的制备与性能研究

使用乙烯-丙烯酸共聚物(EAA)与环氧树脂复配作为基体,利用水基乳液浸渍超高分子量聚乙烯(UHMWPE)纤维制备了复合材料,通过在树脂浸润性、树脂耐热性能、复合材料力学性能、界面结合情况以及微观形貌等方面的测试表征,对比了不同EAA含量的基体树脂对UHMWPE纤维复合材料性能的影响。结果表明,EAA与环氧树脂质量比为25∶75的共混体系一方面可发挥EAA组分与UHMWPE纤维间亲和力强的优势,另一方面还能凭借环氧树脂的刚性交联网络保持较高的耐热性能,体系的层间剪切强度达到8.7 MPa,在60℃下弯曲强度保持率接近80%,表现出优异的综合性能。

STUDY ON THE REACTION MECHANISM OF RADIATION GRAFTING OF ACRYLIC ACID ONTO POLYSTYRENE

It is difficult to find a solvent of grafting copolymer of acrylic acid onto polystyrene, thus it is not easy to analyse its structure by ordinary methods. Until now, many scientists considered that grafting reaction occurs on the main chain of polystyrene. In this work, the radiation grafting mechanism is studied with solid NMR and infrared. We have found that the grafting position is on the meso position of phenyl ring of polystyrene when the solvent is methanol and the matrix is polystyrene and a preirradiation method is used. It

Preparation of Water Based Polymeric Binders for Paper Surface Coating

Binder is an important ingredient in pigment coating as it is used to impart adhesion, gloss and flexibility to the dried film as well as binding the pigment particles together. The aim of this work was to synthesize polymeric binders via radical copolymerization of acrylic acid (AA) with maleic anhydride (MA) and with 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS). The chemical structures of the prepared binders were characterized by FTIR and 1HNMR analysis. The rheology of the prepared binders was also investigated. The prepared binders were applied in paper coating suspensions and their effects on optical, mechanical, and physical properties in addition to printability of the coated paper were studied. The results showed that acrylic maleic anhydride copolymers increased the adhesion, gave good film forming properties and good surface activity which increased print quality of paper coating. It was also found that MA/AA (50:50) and the blend between MA/AA (50:50) with AMPS:AA (30:70) have more suitable coating film properties and have highest pick resistance which is resemble to the commercial binder.

Formulation Development of Generic Omeprazole 20 mg Enteric Coated Tablets

Omeprazole is a potent proton pump inhibitor with powerful inhibition of secretion of gastric juice. Oral site-specific drug delivery systems have recently attracted a great interest for the local treatment of bowel disease and for improving systemic absorption of drugs which are unstable in the stomach. However, microenvironment in the gastrointestinal tract and varying absorption mechanisms cause hindrance for the formulation and optimization of oral drug delivery. The objective of the study was to develop and optimize enteric coating process for omeprazole tablets. Different batches of core tablets were sub coated, one set sub coated with opadry and another with a mixture of light magnesium oxide, magnesium stearate and absolute alcohol omeprazole magnesium. Seal coating was applied by using opadry to achieve certain weight gain and to protect omeprazole from acidic coating polymers. A comparative dissolution test was performed. The variation of thickness and diameter were observed to be minimal with a weight gain of 3% - 4% of enteric polymer. Disintegration test showed that in each tested batch the enteric coated layer remained intact in 0.1N HCl for 2 hours and when exposed to alkaline media of phosphate buffer pH 6.8, it dissolved within few minutes. Dissolution release was 98.8% to 102.4% within two hours when the product was exposed to phosphate buffer pH 6.8 after 2 hours. The similarity and dis-similarity factors were calculated and observed to be 54 to 61 and 4 to 5 respectively. Therefore a simple and good enteric coating process was developed and tested with potential for transfer this technology into local pharmaceutical industries using cheap and easily available materials.

CARBON-13 NMR STUDY ON 4-VINYLPYRIDINEACRYLIC ACID COPOLYMER

Carbon-13 NMR has become a powerful technique in studying polymer structures. A lot of parameters which are important in elucidating polymer structure can be obtained through 13C NMR analysis. Moreover, statistical behavior of monomer addition process can be inspected.

POLYMER-SUPPORTED LANTHANIDE COMPLEXES FOR THE POLYMERIZATION OF BUTADIENE

The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC·Ln was made. It was found that in the polymerization of butadiene, a peak in activity appeared at Nd and Pr, Sin, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1, 4 polybutadiene attained was more than 98%.

EPEG大单体聚合升温与其合成减水剂性能的关联

研究了几种乙烯氧基聚乙二醇EPEG大单体与丙烯酸接枝共聚合成聚羧酸减水剂,在相同条件下进行聚合反应,对EPEG型聚羧酸减水剂合成过程进行升温测试及聚合过程分析,使用凝胶渗透色谱法表征产物的相对平均分子量、分子量分布指数及转化率等结构参数,最后测试产物的水泥净浆流动度、混凝土材料的流动性以及硬化后的力学性能。试验结果表明:不同EPEG大单体聚合活性差异很大,大单体聚合快速升温期在15 min以内的聚合效果好。EPEG聚合放热升温曲线可以作为评价EPEG大单体活性的一种简单有效的方法,EPEG大单体聚合升温曲线与其合成聚羧酸减水剂应用性能二者间有很好的关联性。