球形木素基正离子交换树脂的制备与性能

以木素磺酸钙为原料,在一种价廉无毒的分散介质中通过反相悬浮聚合制备了球形木素基正离子交换树脂。研究了分散介质和分散剂用量、聚合温度及搅拌速度等多种因素对聚合反应和成球效果的影响,并对交换树脂的形貌、粒径、含水量、密度、交换容量及吸附性能进行表征与测;定。结果表明,在实验室条件下,交换树脂对;Cr^3＋的饱和吸附量达到59．28mg／g（干树脂）。     

Synthesis of benzxazine-based nitrogen-doped mesoporous carbon spheres for methyl orange dye adsorption

In this work, nitrogen-doped mesoporous carbon spheres (NMCS) were synthesized through a hard template method by using benzoxazine resin as precursor and ordered mesoporous silica spheres as template. The obtained N-doped mesoporous carbons were amorphous spherical nanoparticles with worm-like mesoporous channels and possessed high surface area of 789 m²/g, large pore volume of 0.49 cm³/g and high nitrogen content of 3.50 wt.%. The adsorption capacity of methyl orange (MO) by NMCS could attain 352.1 mg/g at an optimal condition, while the adsorption capacity of MO by non-doped mesoporous carbon spheres (MCS) was 251.9 mg/g at the same condition. The adsorption process fitted the pseudo-second-order kinetic model and the Langmuir isotherm well. Thermodynamic analysis indicated that the removal of MO by NMCS was spontaneous, endothermic and feasible process. In addition, the adsorption capacity of regenerated adsorbent was 89.04% of the initial level after four regeneration cycles.     

球形聚苯并噁嗪树脂酸催化性能研究

苯并噁嗪预聚体在甲基硅油中经反相悬浮固化法得到球形聚苯并噁嗪树脂,再经磺化反应后制得聚苯并噁嗪树脂酸。通过催化冰醋酸与乙醇的酯化反应来考察该树脂酸的催化活性。结果表明:当V(甲基硅油)∶V(苯并噁嗪预聚体)=100∶6.0、固化温度为200℃左右时,可得到球形聚苯并噁嗪树脂。当磺化温度为45℃、反应时间为3 h和w(催化剂)=4.8%(相对于冰醋酸而言)时,则冰醋酸的转化率为73%;催化剂连续重复使用3次后,其转化率仍超过60%;经磺化再生后的催化剂,其催化活性基本上能完全恢复。     

锂离子吸附球形树脂的合成及其性能研究

为实现高镁锂比盐湖卤水的锂镁分离,合成了一种新的锂离子吸附球形树脂。该树脂采用对锂离子有特定螯合作用的二苯并-14-冠-4为功能单元,并与有机磷酸酯形成对锂离子起协同作用的萃取体系,以聚氨酯为树脂骨架,通过悬浮聚合得到锂离子吸附球形树脂。悬浮聚合以二甲基硅油为分散介质、以粒度为300~400目的碳酸钙为稳定剂、n(羟甲基化产物)∶n(有机磷酯)∶n(甲苯二异氰酸酯)=1∶1∶28,以聚醚多元醇为交联剂、锂溶液为模板致孔剂,反应温度为80℃,时间为10 h,搅拌速度为280 r/min,得到粒度范围为55.36~76.33μm的球形树脂。热分析表明,树脂是均质的,具有较高的热稳定性。树脂经索氏抽提8 h的溶损率为1.5%,说明其在水中使用是稳定的。在pH 7、恒温振荡温度为25℃、振荡时间为4 h条件下,得到树脂对锂的最大吸附容量为0.609 9 mmol/g,其对锂镁选择性系数β=39;经过5次再生实验,其树脂饱和吸附容量仅下降1.8%,表明树脂可多次使用。     

球形聚合单宁-纤维素树脂的制备及吸附性能

单宁与多聚甲醛交联合成单宁酚醛聚合物,再以环氧氯丙烷为交联剂,将单宁酚醛聚合物与纤维素通过反相悬浮交联制备球形聚合单宁-纤维素树脂。通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）对球形聚合单宁-纤维素树脂的结构进行了表征,并考察了球形聚合单宁-纤维素树脂对盐酸小檗碱的吸附性能。结果表明,球形聚合单宁-纤维素树脂具有多孔的结构,树脂网络中含有大量的酚羟基;球形聚合单宁-纤维素树脂对盐酸小檗碱具有较好的吸附性能,当盐酸小檗碱浓度为600 mg·L^-1、吸附温度为298 K时,最大饱和吸附量可达245.92mg·g^-1;球形聚合单宁-纤维素树脂对盐酸小檗碱的吸附过程符合Langmuir吸附等温模型和准二级吸附动力学方程,热力学研究数据表明球形单宁-纤维素树脂对盐酸小檗碱的吸附是一个自发放热的物理吸附过程。该树脂在分离提纯生物碱方面具有潜在的应用前景。     

XDA-8大孔树脂对高浓度咖啡因的吸附热力学研究

测定了不同温度下极性大孔吸附树脂XDA-8对高浓度咖啡因的吸附等温线,并采用Langmuir吸附等温方程进行了拟合,在此基础上对吸附行为进行了热力学研究.结果表明,Langmuir吸附等温方程对吸附过程拟合程度很高,XDA-8大孔树脂对咖啡因的吸附为单分子层吸附;XDA-8大孔树脂吸附咖啡因是一个放热过程,升高温度使其...     

阿司匹林载药淀粉微球吸附热力学和释药动力学的研究

以可溶性淀粉为原料,研究了淀粉微球在反相悬浮体系中不同温度下对阿司匹林的吸附行为,并考察其体外释放情况.结果表明：在实验条件范围内淀粉微球对阿司匹林的吸附量随着阿司匹林浓度的增加而增加.浓度相同时,温度越低,淀粉微球的吸附量也越大.吸附行为更符合Langmuir吸附模型,吸附为自发不可逆过程.总熵变是负值,焓变是主要的吸附驱动力.体外释放结果表明,阿司匹林淀粉微球聚合物在酸性介质中的释放行为更符合Higuchi方程,阿司匹林载药淀粉微球具有缓释作用.     

The influence of montmorillonite concentration and solvent polarity on the synthesis of benzoxazine monomers in the presence of montmorillonite

The synthesis of 3,3′-(hexane-1,6-diyl)bis-(3,4-dihydro-2H-1,3-benzoxazine) was done in the absence and in the presence of 10, 30, 50 and 100 wt.% montmorillonite (MMT). The MMT exhibits a significant catalytic effect on the ring-opening reaction of the benzoxazine monomer, increasing of MMT amount influences the oligomeric structures in the polybenzoxazine precursor composition according to ¹H NMR, ¹³C NMR and SEC data. The influence of solvent polarity and temperature was also studied especially in correlation with possible interactions between solvent and MMT. The influence of the polybenzoxazine precursor composition on the polymerization behaviour was investigated by DSC. The thermostability of the obtained polybenzoxazines was studied by TGA and DMA method was involved to determine the glass transition temperature.     

Adsorption equilibrium and kinetics studies of divalent manganese from phosphoric acid solution by using cationic exchange resin

There are numerous impurities in wet-process phosphoric acid, among which manganese is one of detrimental metallic impurities, and it causes striking negative effects on the industrial phosphoric acid production and downstream commodity. This article investigated the adsorption behavior of manganese from phosphoric acid employing Sinco-430 cationic ion-exchange resin. Resorting FT-IR and XPS characterizations, the adsorption mechanism was proved to be that manganese was combined with sulfonic acid group. Several crucial parameters such as temperature, phosphoric acid content and resin dose were studied to optimize adsorption efficiency. Through optimization, removal percentage and sorption capacity of manganese reached 53.12 wt%, 28.34 mg·g⁻¹, respectively. Pseudo-2nd-order kinetic model simulated kinetics data best and the activation energy was evaluated as 6.34 kJ·mol⁻¹ for the sorption reaction of manganese. In addition, the global adsorption rate was first controlled by film diffusion process and second determined by pore diffusion process. It was found that the resin could adsorb up to 50.24 mg·g⁻¹ for manganese. Equilibrium studies showed that Toth adsorption isotherm model fitted best, followed by Temkin and Langmuir adsorption isotherm models. Thermodynamic analysis showed that manganese adsorption was an endothermic process with enhanced randomness and spontaneity.     

球状壳聚糖树脂对柠檬酸的吸附行为

以壳聚糖为原料采用反相悬浮交联法制备了球状壳聚糖树脂(RCM),通过静态吸附实验研究了RCM对柠檬酸的吸附热力学和动力学特性. 结果表明,吸附符合Laugmuir等温曲线,且平衡常数随着温度升高而升高;吸附是非自发熵增加的吸热过程;在相同的温度下,随着溶液中柠檬酸浓度的增加,吸附势逐渐降低;初始浓度相同时,随着温度的升高吸附势升高;在298, 308, 318 K下,RCM对柠檬酸的饱和吸附量分别为77.0, 80.5, 84.7 mg/g;吸附属二级动力学吸附,粒子内扩散是控速步骤,吸附速率常数随着温度升高而增加.     

Novel organic-inorganic hybrids prepared from polybenzoxazine and titania using sol-gel process

Novel organic-inorganic hybrids were prepared from polybenzoxazine and titania using sol-gel process by blending titanium isopropoxide as a precursor for titania with a typical benzoxazine monomer, bis(3-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (Ba). Deep red brown and transparent hybrid materials were obtained after thermal cure at 200 °C. DSC indicated that, in the presence of titania precursor, the onset and maximum temperature of the exothermic peak due to the ring opening polymerization of Ba decreased by ca. 30 and 70 °C, respectively. Viscoelastic analyses revealed that the glass transition temperatures (T_g) of the polybenzoxazine-titania hybrids shifted to higher temperature than the neat polybenzoxazine. The storage moduli below T_g for the hybrids increased with the increase of the titania content, and the storage moduli were maintained constant up to higher temperature than the neat resin. TGA results confirmed that the thermal stability and char yield of polybenzoxazine increased by hybridization with titania.     

Preconcentration and determination of chromium in water with flame atomic absorption spectrometry by thiourea-formaldehyde as chelating resin

Thiourea-formaldehyde chelating resin is synthesized simply and rapidly from thiourea and formaldehyde by condensation polymerization and characterized by IR spectra and studied for the preconcentration and determination of trace Cr(III) ion from solution samples. The optimum pH value for sorption of the metal ion was 6.5. The sorption capacity of resin for Cr(III) was determined. The chelating resin can be reused for 20 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 96% was obtained for the metal ion with 0.5M HNO₃ as eluting agent. The equilibrium adsorption data of Cr(III) on modified resin were analyzed by Langmuir, Freundlich and Temkin models. Based on equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined as 0.016, 0.040 and 0.074 at pH 6.5 and 20°C. The method was applied for chromium ion determination from river water sample.     

Functionalization in copolymers based on 4VP:DVB for the removal of Cr(VI) ions from aqueous solution

Adsorption capacity for Cr(VI) ions has been evaluated on two ion‐exchange resins. A gel‐type precursor resin was obtained by suspension polymerization of 4‐vinylpyridine and divinylbenzene monomers with 40% crosslinking degree. It was quaternized with different functional groups to give two ion‐exchange resins. The R2 resin contained sulfobetaine groups, and R3 methyl groups. The resins were characterized by Fourier transform infrared and solid‐state ¹³C CP/MAS NMR spectroscopy and by elemental analysis. An adsorption experiment was carried out by a batch equilibrium procedure. Langmuir and Freundlich isotherm models were used to determine the adsorption capacity. R2 and R3 resins exhibited maximum adsorption capacity q_max = 75.8 and 56.2 mg/g, respectively. The resins achieve equilibrium in 60 min. The R3 and R2 resins showed a retention capacity of 95% and 80% for the Cr(VI) ions, respectively. The behaviors of both resins were explained well by a pseudo‐second‐order kinetics model. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45548.     

乙二胺改性淀粉GMA共聚物对Pb(Ⅱ)的吸附性能

以木薯淀粉为原料,通过接枝共聚、环氧开环反应,得到富含-NH2官能团的新型氨基改性淀粉(AMS),用FT-IR、SEM和XRD对其结构进行表征。在静态条件下,研究了AMS对水溶液中Pb(Ⅱ）的吸附性能和吸附热力学,考察了溶液pH值、吸附时间、Pb(Ⅱ）初始浓度及温度对AMS吸附性能的影响。结果表明：pH相似文献   

Preparation and coordination with Hg(II) of sulfur‐ and 2‐amino‐pyridine‐containing chelating resin

A novel chelating resin anchoring 2‐amino‐pyridine on macroporous crosslinked polystyrene beads via a sulfur‐containing spacer (PVBS‐AP) has been synthesized and its structures were characterized by FTIR, scanning electron microscopy, porous structure analysis, and elementary analysis. The results of scanning electron microscopy and pores analysis demonstrated that PVBS‐AP resin had meso‐macro porous structure. Its adsorption properties for Hg(II), Pd(II), Ni(II), Cu(II), Zn(II), Pb(II), and Cd(II) were investigated. Some factors affecting the adsorption of PVBS‐AP resin for Hg(II), such as temperature, contact time, ion concentration, and pH were also studied. The results showed that the increasing of temperature was beneficial to adsorption and Langmuir model was much better than Freundlich model to describe the isothermal process. PVBS‐AP resin had good adsorption selectivity for Hg(II). It could selective adsorb Hg(II) from such binary ions system as Hg(II)‐Ni(II), Hg(II)‐Zn(II), and Hg(II)‐Pb(II), their selective coefficients are α_Hg/Ni = ∞, α_Hg/Zn = 28.1, α_Hg/Pb = ∞, respectively. Five adsorption–desorption cycles demonstrate that this resin were suitable for reuse without considerable change in adsorption capacity. POLYM. ENG. SCI., 47:721–727, 2007. © 2007 Society of Plastics Engineers.     

The effect of polystyrene as a porogen on the fluoride ion adsorption of Zr(IV) surface-immobilized resin

A novel adsorbent, Zr(IV)-immobilized resin, was prepared by surface template polymerization. This adsorbent, prepared by adding polystyrene (PS) to resin, has a high adsorption capacity for the removal of fluoride ion from aqueous solutions. The adsorption capacity increased with rising PS concentration, since the specific surface area can be effectively increased by adding polystyrene as a porogen. The adsorption isotherm has been modeled by the Langmuir and Freundlich equations. The adsorption isotherms were well described by the Langmuir equation. The removal of fluoride was also carried out using a column method. The presence of PS in the resin exerted a remarkable influence on the uptake of fluoride ion. The fluoride adsorbed on the resin was quantitatively eluted with 0.1 M NaOH.     

SQD201树脂对钒的吸附-解吸行为及机理

通过静态吸附-解吸实验研究了SQD201树脂吸附-解吸钒的交换平衡和动力学特性,考察了pH值、温度和溶液浓度对离子交换过程的影响. 结果表明,在298 K、pH=2.0、溶液浓度为0.040 mol/L条件下,SQD201树脂的静态饱和吸附量为573.80 mg/g;钒在SQD201树脂上的吸附是吸热过程,符合Langmuir等温吸附方程. 吸附和解吸过程主要受颗粒扩散控制,吸附过程的表观活化能为20.41 kJ/mol,解吸表观活化能为22.21 J/mol. 吸附机理分析表明,SQD201树脂主要吸附的钒阴离子为H2V10O284-,H2V10O284-与树脂的理论摩尔比为1:4.     

Reinforcement of polybenzoxazine matrix with organically modified mica

Novel polybenzoxazine–clay hybrids were prepared by the in situ polymerization of the typical benzoxazine monomer, bis(3‐phenyl‐3,4‐dihydro‐2H‐1,3‐benzoxazinyl)isopropane (B‐a) in the presence of aminolauric acid‐modified mica (ALA‐mica). Various ratios of ALA‐mica were dispersed into solutions of B‐a in N,N‐dimethylacetamide, followed by casting into film form. The hybrids were thermally cured up to 230°C, affording transparent nanocomposite films up to 10 wt% of mica loadings. The cure behavior was monitored by both IR and differential scanning calorimetry, indicating the catalytic effect of the modified mica. The morphology of the nanocomposites was studied by XRD, showing a featureless pattern, which suggests the disordered dispersion of mica into polybenzoxazine matrix. The dynamic mechanical properties of some hybrids show that the nanocomposites have higher storage modulus over the whole temperature range than the neat polybenzoxazine. Thermogravimetric analysis results confirmed that the thermal stability and char yield of polybenzoxazine resin increased apparently by hybridization with mica corresponding to the mica content. POLYM. COMPOS., 28:680–687, 2007. © 2007 Society of Plastics Engineers     

大孔树脂对贯叶连翘中金丝桃素的静态吸附

考察了18种不同类型的大孔树脂对贯叶连翘中金丝桃素的静态吸附和解吸效果,并对3种效果较好的树脂进行了吸附动力学研究;比较了上样液pH对吸附效果的影响;探讨了NKA-9树脂在25℃等温吸附过程,并应用Langmuir方程进行了拟合。结果表明,弱极性树脂NKA-9对金丝桃素吸附解吸作用最好,到达吸附平衡时间为1h左右,吸附量可达12.45mg/g干树脂。上样液最佳pH=4,上样液pH对树脂的吸附有很大影响。NKA-9树脂对金丝桃素的吸附为单分子吸附,符合Langmuir吸附理论。     

Adsorption of trypsin onto magnetic ion‐exchange beads of poly(glycidylmethacrylate‐co‐ethyleneglycoldimethacrylate)

Magnetic beads were prepared from glycidyl methacrylate (GMA), and ethyleneglycol dimethylmethacrylate (EGDMA) in the presence of Fe₃O₄ nano‐powder via suspension polymerization. The magnetic beads were characterized by surface area measurement, electron spin resonance (ESR), and scanning electron microscopy (SEM). ESR data revealed that the beads were highly super‐paramagnetic. The effects of contact time, pH, ionic strength, and temperature on the adsorption process have been studied. Adsorption equilibrium was established in about 120 min. The maximum adsorption of trypsin on the magnetic beads was obtained as 84.96 mg g^?1 at around pH 7.0. At increased ionic strength, the contribution of the electrostatic component to the overall binding decreased, and so the adsorption capacity. The experimental equilibrium data obtained trypsin adsorption onto magnetic beads fitted well to the Langmuir isotherm model. The result of kinetic analyzed for trypsin adsorption onto magnetic ion‐exchange beads showed that the second order rate equation was favorable. It was observed that after six adsorption–elution cycle, magnetic beads can be used without significant loss in trypsin adsorption capacity. Finally, the magnetic beads were used for separation of bovine serum albumin (BSA) and trypsin from binary solution in a batch system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008