Synthesis of divinylbenzene-crosslinked terpolymer consisting of hemin,styrene, and 1-venyl-2-methylimidazole as cyanide ion exchanger

Summary Crosslinked terpolymers, consisting of hemin (ferriprotoporphyrin IX chloride), styrene (St), and 1-vinyl-2-methylimidazole, were obtained in satisfactory yield (>70 %) by radical polymerization in which a part of St monomer was replaced with divinylbenzene. These terpolymers showed an ability to function as a cyanide ion exchanger.     

Ternary copolymers of hemin,styrene, and 1-vinylimidazole or 1-vinyl-2-methylimidazole as cyanide ion exchanger

Ternary copolymers, involving hemin (H) (ferri-protoporphyrin IX chloride), styrene, and 1-vinylimidazole (VI) or 1-vinyl-2-methylimidazole (VMI) in the different proportions, were synthesized by radical copolymerization. All the copolymers obtained were insoluble in aqueous solvents. No dissolution of H from the copolymers was observed even when the extraction with 0.5N NaOH or HCl was allowed to continue for a total time of 50 days. To clarify the functional capabilities of the ternary copolymers as a cyanide ion exchanger, the adsorption of cyanide ion onto the copolymers was investigated at different pHs. The amount (A_cn) of the adsorbed cyanide ion was found to be dependent on the content of H residue in the copolymer, thus indicating that the adsorption site for the cyanide ion consists of ferri-protoporphyrin IX (FP). Another important feature is that A_cn increases in proportion to the VI or VMI content of the copolymer. This result was discussed in terms of the coordination structure of the FP and also of the coordination reaction of cyanide ion to the FP.     

Divinylbenzene-crosslinked terpolymer consisting of hemin,styrene, and 2-methyl-5-vinylpyridine as cyanide ion exchanger. Preparation of the polymer in the form of beads by suspension polymerization

Bead-shaped, divinylbenzene-cross-linked terpolymers, consisting of hemin (ferri-protoporphyrin IX chloride), styrene, and 2-methyl-5-vinylpyridine, were prepared by suspension polymerization in which all or part of styrene monomer was replaced with divinylbenzene. Analogous terpolymers of the cross-linked and uncross-linked formless types were also prepared by solution polymerization. All the terpolymers obtained were characterized by electron spin resonanance spectroscopy, scanning electron microscopy, and measurement of specific surface area. The characteristic of the adsorption of cyanide ion onto the terpolymer beads was investigated and compared with those adsorbed onto their analogs. The column separation of cyanide ion with the terpolymer beads was carried out to examine the ion-adsorbing capacity. It was found that the suspension polymerization is just appropriate to prepare a cyanide ion exchanger in the form of beads.     

官能化丁苯渐变嵌段共聚物树脂的合成与表征

采用溶液聚合法,以官能化偶联剂合成了带有HN-,HO-,HS-的官能化丁二烯-苯乙烯渐变嵌段共聚物.结果表明,该聚合物为单形态的三臂或四臂星形共聚物,具有良好的透光率和耐环境开裂性以及较好的耐氧化性、耐热性和表面粘接性,可应用于医疗器械、儿童玩具、食品容器等行业.     

Coordination behavior of cyanide ion to hemin uncomplexed and complexed with several synthetic polymer ligands

Hemin (H) (ferri–protoporphyrin IX chloride) was complexed in aqueous media with the following polymer ligands; poly(L -lysine), poly(L -histidine), branched polyethyleneimine, and two copolymers of 1-vinyl-2-pyrrolidone with 1-vinylimidazole and with 1 -vinyl-2-methylimidazole. The resulting water-soluble complexes were either the five- or six-coordinate hemichromes, respectively, which coordinated one or two ligand units in polymer to ferri—protoporphyrin IX (FP). The coordination behavior of cyanide ion to the hemichromes and also to H was investigated by means of spectroscopic titration method. It was found that one cyanide ion binds not only to the five-coordinate hemichromes, but also to the six-coordinate ones by the ligand exchange reaction with the cyanide ion, whereas two cyanide ions coordinate to H, which is free from polymer ligand able to occupy the coordination site(s) of FP. Morever, the degree of saturation of the iron(III) in FP with cyanide ion for all the hemichromes was found to be much larger than that for H. These results indicate that the ability of FP to coordinate cyanide ion is closely associated with whether one coordination site of FP is occupied by polymer ligand or not.     

On the function of the polyion complex of methemoglobin and polyelectrolytes as cyanide ion exchanger

The binding of cyanide ion to Fe(III) in the hemes of bovine methemoglobin and insoluble polyion complex (KPVS-Hb-PDDA complex) prepared by the complexation of the methemoglobin with potassium poly(vinyl alcohol) sulfate and poly(diallyldimethylammonium chloride) was investigated as functions of pH and potassium cyanide concentration by spectrophotometric method and adsorption experiment. The degree of saturation of the cyanide ligand on the heme showed a maximal value at pH range 8–9, whereas this was reduced to zero in the strongly acidic and basic regions, below pH 3.5 and above pH 13.5. These results were in agreement, in a qualitative way, with the theoretical results represented by four equilibrium reactions between methemoglobin and potassium cyanide at different pH and cyanide concentrations. The separation of cyanide ion in Na₂B₄O₇? KH₂PO₄ buffer solution at pH 9.0 was also investigated by using a KPVS-Hb-PDDA complex column. The cyanide ion in the solution was mostly or entirely bound to the complex until the heme was saturated with cyanide ion, and most of the bound cyanide ion was eluted with 0.1N NaOH solution. These results indicate that KPVS-Hb-PDDA has a function as cyanide ion exchanger and that the exchange reaction is analogous to that for methemoglobin.     

丙烯酸丁酯/苯乙烯/功能单体多元共聚乳液的合成

通过一步加料和滴加引发剂的方法合成了丙烯酸丁酯、苯乙烯和功能单体的多元共聚乳液,对其性能进行了表征。结果表明:在合适的单体配比条件下,可以得到一种较高固含量、低粘度,且具有良好稳定性的共聚乳液。     

用于包覆丙烯腈-丁二烯-苯乙烯共聚物的苯乙烯嵌段共聚物热塑性弹性体的制备与性能

以苯乙烯-乙烯-丁烯-苯乙烯嵌段共聚物(SEBS)为基体,白油为增塑剂,热塑性聚氨酯(TPU)为极性改性剂,SEBS接枝马来酸酐(SEBS-g-MAH)为相容剂,利用双螺杆挤出机共混挤出制备了用于包覆丙烯腈-丁二烯-苯乙烯共聚物(ABS)的包覆料,考察了填料种类和TPU、白油及SEBS-g-MAH的用量对包覆料物理机械性能、黏结性能及微观相态的影响。结果表明,随着TPU用量的增加,SEBS包覆料的邵尔A硬度、拉伸强度和扯断伸长率均提高,且对ABS的剥离强度增大,综合考虑,TPU最佳用量为50份;在碳酸钙、滑石、云母和高岭土4种填料中,碳酸钙填充的SEBS包覆料对ABS的剥离强度最佳,滑石的效果最差;随着白油用量的增加,SEBS包覆料对ABS的剥离强度减小;加入SEBS-g-MAH后,SEBS包覆料的相界面不明显,趋向于形成连续相结构;随着SEBS-g-MAH用量的增加,包覆料对ABS的剥离强度先增大后减小,当SEBS-g-MAH用量为5份时,剥离强度达到最大值(2.5 k N/m)。     

Preparation and characterization of carboxylated isoprene/styrene copolymer latexes

Carboxylated isoprene/styrene copolymer latexes were prepared, and the concentration of surface carboxyl groups and the freeze–thaw stability of these latexes were measured. It is clarified that the introduction method of the carboxylic monomer governs the distribution of carboxyl groups in latex particles. Introduction of the carboxylic monomer prior to the initiation of polymerization localizes only 12–13% of total carboxyl groups on the surface of particles, whereas introduction of the carboxylic monomer at the last stage of polymerization localizes more than 60% of total carboxyl groups on the surface of particles, though the percentage is strongly dependent on the conversion when the monomers are shot. These latexes show a remarkable increase in the freeze–thaw stability with the increase in the degree of neutralization of surface carboxyl groups in a fairly narrow range. There exists a linear relationship between the surface area occupied by a surface carboxyl group and the degree of neutralization of surface carboxyl groups at which the remarkable increase in the freeze–thaw stability is observed. The result suggests that the freeze–thaw stability is substantially determined by the density of carboxylate ion on the surface of particles.     

Morphology of polymer of ethylene sulfide and its block copolymer with styrene

It has been found that poly(ethylene sulfide) obtained by anionic polymerization in tetrahydrofuran assumes the shapes of platelets, microhedrites, microspherulites, or particles of irregular structure, depending upon the molecular weight of poly(ethylene sulfide). In the case of block copolymers of ethylene sulfide and styrene, the morphological form has been found to be dependent upon the composition of the copolymer.     

Simultaneous removal of cyanide and copper ions in a semi-fluidized ion exchanger bed

Simultaneous removal of cyanide and copper ions from electroplating wastewater was studied in a liquid-solid semi-fluidized ion exchanger bed. The diameter and the height of column are 20 mm and 600 mm, respectively. Strong-base anion exchange resin particles (Dowex 1X8-50) were contacted with synthetic solutions containing copper and cyanide ions. Cyanide and copper ions in the solution were analyzed by a cyanide electrode and ICP (inductively coupled plasma), respectively. The ion exchange equilibrium data of Cu⁺ removed as cyanide-copper complexes on Dowex 1X8-50 at 25 ‡C can be fitted with the Langmuir equation. Early leakage of cyanide from experimental loading profile data results in not only lower selectivity of free cyanide but also different selectivities of CN-Cu complexes due to the size and the structure of complexes. The optimum molar ratio (Q) between cyanide and copper ions is about 3 to obtain a reasonable removal rate of cyanide in this experiment.     

Preparation and characterization of graft copolymer from dealkaline lignin and styrene

Graft copolymerization of styrene onto dealkaline lignin by ferrous chloride and hydrogen peroxide coinitiator has been achieved successfully. The influence of temperature and reaction time as well as the amount of the styrene monomer, initiator, and catalyst on the grafting copolymerization was investigated. The optimum reaction conditions were determined as follows: c (styrene) = 20.00 mmol, c (H₂O₂) = 5.00 mmol, c (FeCl₂) = 0.10 mmol, T = 30°C and t = 48 h. The optimum yield (Y), total conversion (TC), grafting efficiency (GE), and degree grafted (DG) values were 96.6, 96.3, 59.5, and 53.7%, respectively. The copolymer of lignin grafted PS was separated and characterized by elemental analysis, differential scanning calorimetry, Fourier transform infrared, thermogravimetry analysis, field emission‐scanning electron microscopy, gel permeation chromatography, and nuclear magnetic resonance. It was demonstrated that the solubility what the copolymer exhibited turned out to be the very reverse of the original lignin. The surface properties and structure of lignin were completely changed after grafting copolymerization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41900.     

Preparation and characterization of a phosphonylated polypropylene ion exchanger

Because typical ion exchange resins used for treating wastewater contain sulfur binding sites and suffer from application limitations, a new ion exchange system was developed by phosphonylating nonwoven polypropylene fabric (PP). These fabrics were phosphonylated for 0.5, 1, 2, and 4 h; amount of phosphorus on phosphonylated PP increased with an increase in phosphonylation time. After hydrolysis, the appropriate phosphonylated sample was placed in a glass column where a europium (Eu³⁺), lead (Pb²⁺), or mercury (Hg²⁺) salt solution was passed through the fabrics after an equilibration period of 5 min. Filtrate samples were then analyzed by atomic absorption spectroscopy for metal concentration. Results showed that metal binding efficiency for Eu³⁺ increased with an increase in phosphonylation time; Pb²⁺ binding efficiency increased up to 2 h phosphonylation time and then decreased; Hg²⁺ binding efficiency was practically independent of phosphonylation time. PP fabrics were also sulfonated and tested for binding efficiency to determine if phosphorus was a better binding site than sulfur. By comparing the results from phosphonylated PP and sulfonated PP, data showed that phosphonylated PP bound metal ions at a higher efficiency than sulfonated PP. Also, phosphonylated PP had higher binding efficiencies with Eu³⁺ and Pb²⁺ than a commercial exchange resin. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 93–100, 2000     

Preparation of DEAE cotton-g-poly(methacrylic acid) for use as ion exchanger

Diethylaminoethyl (DEAE) cottons having different % N were prepared by reacting cotton cellulose in the fabric form with diethylamine hydrochloride at different concentrations in the presence of sodium hydroxide. The modified samples so obtained were subjected to the graft polymerization reaction using methacrylic acid (MAA) as the vinyl monomer and potassium permanganate-citric acid system as the initiator. The percentage of grafting (PG) was found to increase by increasing the % N, indicating that the presence of the DEAE groups in the molecular structure of the cellulose enhances the susceptibility of the latter to grafting. DEAE groups seem to act as additional sites for grafting; and/or, by virtue of their basicity, they interact with the citric acid, thereby creating primary free radicals in the vicinity of the cellulose. As a result, grafting increases, increasing the initiator and monomer concentration, as well as the polymerization time and temperature functions in favor of the PG. It was also disclosed that DEAE cotton-g-poly (methacrylic acid) serves as cationic and anionic ion exchanger by virtue of the presence of both DEAE and carboxylic groups. This was evidenced by the results of a detailed investigation on the ability of the exchanger to adsorb direct and basic dyes as well as Cu²⁺ ions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 739–745, 1998     

阳离子改性苯乙烯-马来酸酐共聚物的制备与表征及应用

以2,3-环氧丙基三甲基氯化铵(ETA)为阳离子化试剂,对苯乙烯-马来酸酐共聚物(SMA)进行阳离子化改性,制备出一种阳离子性高分子分散剂(SMG)。通过红外光谱、含氮量、表面张力以及溶解性等的测定,研究了SMG的结构与性质;通过对颜料黄14的分散性考察,研究了SMG的分散性能。结果表明,SMA在阳离子化过程中,酸酐基团全部开环,部分形成酯键,阳离子化度达到7.5%左右;SMG的表面活性较低,但对颜料黄14的分散稳定性较好,在pH=7.0条件下,可以使颜料的Zeta电位提高至 35.4 mV。     

丙烯酸-丙烯酸丁酯-丙烯酰胺三元共聚物分散剂的制备与分散性能

以丙烯酸(AA)、丙烯酸丁酯(BA)为主单体,与功能单体丙烯酰胺(AM)进行共聚,合成了一系列三元共聚物分散剂,主要研究了链转移剂、引发剂和AM的用量对共聚物粘度的影响,并考察了链转移剂、AM、共聚物分散剂、偶联剂用量、纳米TiO2浓度、pH值等因素对纳米TiO2颜料水性分散体系稳定性的影响。结果表明,随着AM的用量增加,共聚物分散剂对纳米TiO2的分散效果逐渐增强;当n(AM)∶n(BA)∶n(AA)=0.09∶1∶1.5,引发剂(BPO)用量为单体总量的1.2%,链转移剂为单体总量的4%时,所制得AA-BA-AM三元共聚物分散剂的粘度为150 mPa.s,对纳米TiO2颗粒的分散效果最佳;且其优化分散条件为:合成分散剂用量16%,偶联剂用量3%,纳米TiO2水溶液浓度3%,pH值10。     

新型无机离子交换剂TiWP2的制备与研究

利用正交实验确定了焦磷钨酸钛的最佳合成条件,对合成产品进行了离子交换性能评价和微观结构表征。研究表明,焦磷钨酸钛是具有一定晶化趋势的无定形物质,具有较大的离子交换容量和分配系数,以及较好的动力学交换性能,这些性能在酸性介质中又尤为突出。因此,作为一种优良的多功能基离子交换材料,焦磷钨酸钛将在水处理等工业领域发挥巨大的作用。