Preparation and adsorption behavior of macrocyclic tetra‐amine derivatives of chitosan

The new macrocyclic polyamine derivatives of chitosan were synthesized by reacting epoxy‐activated macrocyclic tetra‐amine with the C6 hydroxyl or C2 amino group in chitosan. The obtained copolymers (CTS‐OM, CTS‐NM) contain amino functional groups, the secondary amines, and more polar hydroxyl groups in its skeleton. Elemental analysis, infrared spectra, and solid‐state ¹³C‐NMR analysis confirmed their structures. The adsorption behavior of the macrocyclic polyamine grafted chitosan for Ag⁺, Pb²⁺, Hg²⁺, and Cr³⁺ was investigated. The experimental results showed that the two novel derivatives of chitosan have high adsorption capacity and good selectivity for some metal ions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 407–412, 2005     

多胺型螯合树脂的制备及吸附性能研究

采用悬浮聚合方法,以丙烯酸和苯乙烯为共聚单体、二乙烯苯为交联剂、甲苯和环已烷为混合致孔剂,引入多胺基团,合成了一系列多胺型螯合树脂.研究了共聚单体比例、致孔剂用量、交联剂用量、多胺基团结构以及吸附条件对树脂螯合金属镍离子性能的影响.研究表明,在n (AA):n(St)=2.17、交联剂用量(占共聚单位质量)15%、致孔剂用量(占共聚单位质量)50%的条件下合成的树脂外观规整.以二乙烯三胺为螯合基团,在pH=5时,树脂吸附Ni2+的性能最佳,吸附容量达37.7mg/g,优于目前的离子交换树脂.     

Organic and conventional fertilisation procedures on the nitrate,antioxidants and pesticide content in parts of vegetables

Different parts of plant foods are generally discarded by consumers such as peel, stalk and leaves, which could however possess a nutritional value. However, few studies have analysed the composition of these marginal foods. The phenolic compound, flavonoid, polyamine, nitrate and pesticide contents of parts of vegetables that are usually discarded – but which were cultivated according to conventional and non-conventional procedures – were analysed to provide suggestions on how to improve the consumption of these parts and to reduce the production of urban solid waste. Few, but significant, differences between the two manuring procedures were observed. Higher nitrate content and the presence of organochlorine pesticides were found in conventional cultivated papaya peel, lemon balm leaves, jack fruit pulp, and beet stalk and peel. Discarded parts of plant foods such as stalk, leaves and peels can be used as a source of antioxidant compounds, such as phenolic compounds.     

新型有机多胺Zn(Ⅱ)配合物的合成、晶体结构及抑菌性能研究

本文合成了[Zn(L)HCl](ClO4)2(L=1-(N,N-二氨基丙基)氨基乙基-4-氨基丙基哌嚷),通过溶剂扩散法培养目标物单晶,产物的结构通过单晶X-射线衍射确定,其晶体属于正交晶系.空间群Pna2(1),a=13.8634(12),b=21.195(3),c=8.5982(10)(A),Mr=601.23,V=2526.4(5)(A)3,Z=4,F(000)=1256,Dc=1.581 g/cm3,μ(MoKa)=1.341 m-1最终偏离因子R1=0.0776,wR2=0.1801.通过琼脂扩散抑菌法测定了产物抑菌性能,该化合物对金黄色素葡萄球菌、大肠杆菌、枯草芽孢杆菌、鳗弧菌抑菌效果明显.     

Preparation and coordination behavior of cellulose beads derivative modified by 1,5‐diaminoethyl‐3‐hydroxy‐1,5‐diazacycloheptane

Cellulose derivative (MPCN) modified by 1,5‐diaminoethyl‐3‐hydroxy‐1,5‐diazacycloheptane (DADN) was prepared and characterized by scanning electron microscopy and elemental, and infrared analysis. MPCN and its Cu²⁺, Pb²⁺ complexes were characterized by thermogravimetric and differential thermal analysis. The coordination adsorption behavior of MPCN with divalent copper and lead ions was determined. The effects of temperature, initial pH value, and the concentration of MPCN ligand to the equilibrium adsorption were discussed. The optimum pH range of the coordination adsorption of MPCN with Cu²⁺ and Pb²⁺ is 5–6. The rate constants of the coordination reaction were found. At 323 K, the rate constant is 1.0 × 10⁻³ and 7.0 × 10⁻⁴ s⁻¹ for Cu²⁺ and Pb²⁺, respectively. The thermodynamic parameters of the coordination reaction were obtained based on the experiment data of the adsorption isotherms. The coordination reaction was performed spontaneously from the data of ΔG, as follows: −21.65 and −19.41 kJ/mol and ΔS, 87.06 and 67.92 J/mol K for Cu²⁺ and Pb²⁺, respectively. The coordination ratio of DADN coordination group immobilized on cellulose beads with either metal ion is about 1 : 2 from the plot of the relation of lgD versus lgL and the capacity of saturation adsorption. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1278–1285, 1999     

Polyamine Oxidase Triggers H2O2-Mediated Spermidine Improved Oxidative Stress Tolerance of Tomato Seedlings Subjected to Saline-Alkaline Stress

Saline-alkaline stress is one of several major abiotic stresses in crop production. Exogenous spermidine (Spd) can effectively increase tomato saline-alkaline stress resistance by relieving membrane lipid peroxidation damage. However, the mechanism through which exogenous Spd pre-treatment triggers the tomato antioxidant system to resist saline-alkaline stress remains unclear. Whether H₂O₂ and polyamine oxidase (PAO) are involved in Spd-induced tomato saline-alkaline stress tolerance needs to be determined. Here, we investigated the role of PAO and H₂O₂ in exogenous Spd-induced tolerance of tomato to saline-alkaline stress. Results showed that Spd application increased the expression and activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and the ratio of reduced ascorbate (AsA) and glutathione (GSH) contents under saline-alkaline stress condition. Exogenous Spd treatment triggered endogenous H₂O₂ levels, SlPAO4 gene expression, as well as PAO activity under normal conditions. Inhibiting endogenous PAO activity by 1,8-diaminooctane (1,8-DO, an inhibitor of polyamine oxidase) significantly reduced H₂O₂ levels in the later stage. Moreover, inhibiting endogenous PAO or silencing the SlPAO4 gene increased the peroxidation damage of tomato leaves under saline-alkaline stress. These findings indicated that exogenous Spd treatment stimulated SlPAO4 gene expression and increased PAO activity, which mediated the elevation of H₂O₂ level under normal conditions. Consequently, the downstream antioxidant system was activated to eliminate excessive ROS accumulation and relieve membrane lipid peroxidation damage and growth inhibition under saline-alkaline stress. In conclusion, PAO triggered H₂O₂-mediated Spd-induced increase in the tolerance of tomato to saline-alkaline stress.     

改性淀粉/聚胺复合物在石材加工废水处理中的应用研究

研究了改性木薯淀粉和聚胺复合物在高浊度、高SS及高色度的石材加工废水中的絮凝性能.实验结果表明,复合物的用量为8 mg/L、沉降时间为30 min时,可使废水(pH=9)的主要污染指标达到国家污水排放二级标准,其处理成本分别是聚合氯化铝(PAC)、CPAM和聚胺的44%、36%和50%,对石材加工废水处理显示出优越的性价比.     

含有聚醚多胺环氧树脂网络的形态及力学性能

不同相对分子质量聚醚多胺与环氧树脂于６０℃混合后,加入固化剂二乙烯三胺,在８０℃＊ｈ,１２０℃＊４ｈ下固化,可制备含聚醚多胺的固化环氧树脂网络。     

New AMP/polyamine blends for improved CO2 capture: Study of kinetic and equilibrium features

2-Amino-2-methyl-1-propanol (AMP), which is the sterically hindered form of monoethanolamine (MEA), is a credible substitute to conventional CO₂-capturing solvents. Its performance can be improved by blending with a highly reactive polyamine promoter. Two such aqueous blends of AMP/TETA and AMP/TEPA were chosen here (TETA = triethylenetetramine and TEPA = tetraethylenepentamine). The kinetics of CO₂ absorption in the proposed blends was investigated at 308, 313, and 318 K using the stirred cell technique. The concentrations of AMP and polyamine were varied between 2 to 3 kmol/m³ and 0.1 to 0.5 kmol/m³, respectively. From the measured values of the fast pseudo-first order constants, the second-order rate constants for the reactions of CO₂ with TETA (14 695 m³/(kmol s)) and TEPA (19 250 m³/(kmol s)) were determined at T = 313 K. Both TETA and TEPA react faster with CO₂ than MEA. Further, the respective activation energy values were found (40 and 37 kJ/mol). Finally, the equilibrium solubility of CO₂ for both blends was measured at T = 303 K. The loading capacity was higher than that for the aqueous blends of AMP/MEA, AMP/DEA, and AMP/MDEA (here, DEA and MDEA denote diethanolamine and N-methyldiethanolamine). The highest value of loading capacity (1.12 mol CO₂/mol amine at 2.01 kPa equilibrium partial pressure of CO₂) was noted in AMP/TEPA mixtures. The new findings on our proposed blends will strengthen the AMP/polyamine application in CO₂ separation.     

Immobilization of invertase onto dimer acid‐co‐alkyl polyamine

Invertase was immobilized onto the dimer acid‐co‐alkyl polyamine after activation with 1,2‐diamine ethane and 1,3‐diamine propane. The effects of pH, temperature, substrate concentration, and storage stability on free and immobilized invertase were investigated. Kinetic parameters were calculated as 18.2 mM for K_m and 6.43 × 10^?5 mol dm^?3 min^?1 for V_max of free enzyme and in the range of 23.8–35.3 mM for K_m and 7.97–11.71 × 10^?5 mol dm^?3 min^?1 for V_max of immobilized enzyme. After storage at 4°C for 1 month, the enzyme activities were 21.0 and 60.0–70.0% of the initial activity for free and immobilized enzyme, respectively. The optimum pH values for free and immobilized enzymes were determined as 4.5. The optimum temperatures for free and immobilized enzymes were 45 and 50°C, respectively. After using immobilized enzyme in 3 days for 43 times, it showed 76–80% of its original activity. As a result of immobilization, thermal and storage stabilities were increased. The aim of this study was to increase the storage stability and reuse number of the immobilized enzyme and also to compare this immobilization method with others with respect to storage stability and reuse number. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1526–1530, 2004