聚环氧氯丙烷的合成与表征

环氧丙烷-三氯化铁、环氧氯丙烷-二乙基氯化铝和铝卟啉-环氧氯丙烷体系是合成分子量为10~4数量级晶态和10~5数量级非晶态聚环氧氯丙烷的比较理想的体系。利用合成产物的分级试样确定了非晶态聚环氧氯丙烷的Mark-Houwink方程。     

改性三聚氰胺树脂鞣剂合成

本文采用一种全新的乙醇胺醚化－－助剂体系改性三聚氰胺树脂鞣剂，并通过研究单体，醚化剂，助剂用量，浓度，pH变化等工艺条件，获得了稳定性，水溶性良好的鞣剂产品。     

环氧氯丙烷类阳离子改性絮凝剂的合成及性能研究

为提高环氧氯丙烷胺类絮凝剂的絮凝性能,选用六次甲基四胺为交联剂,以环氧氯丙烷、二甲胺为主要原料,合成了环氧氯丙烷-二甲胺-六次甲基四胺(HMTA)季铵盐阳离子改性絮凝剂,其在辽河油田废水处理中表现出优异的絮凝性能,并研究了絮凝剂用量和温度对HMTA絮凝剂絮凝性能的影响。结果表明,使用HMTA絮凝剂的合适温度为45℃,最佳用量为20mg/L,除浊率可达98. 1%,除油率达到35. 1%。红外光谱和核磁共振谱的表征结果证实六次甲基四胺在聚合物中发挥了交联剂的作用,有效提高了环氧氯丙烷胺类絮凝剂的絮凝性能。     

水体中环氧氯丙烷监测方法研究进展

介绍环境水体中的环氧氯丙烷监测分析方法及相关的研究进展。相关文献显示,用盐酸溶液（1+1）酸化样品有利于样品保存,采用全自动吹扫捕集处理技术,对吹扫时间、温度、色谱柱和检测器等参数进行优化。如吹扫时间设定为13 min,吹扫温度设定为35℃,经DB-624毛细管色谱柱分离,质量选择检测器进行检测,可以更好实现对水体中痕量环氧氯丙烷的富集、解析和检测。在各种环氧氯丙烷的测定方法中,选择吹扫捕集–气相色谱和质谱联用法,可实现全自动的样品前处理,其高效而且不用接触有机溶剂,检测方法步骤简单、准确性高、选择性好,在水质环氧氯丙烷测定方面具有广阔的应用前景。     

手性环氧氯丙烷的制备及其药物应用

手性环氧氯丙烷作为医药和化工等领域的重要中间体, 可以从廉价的外消旋体中分离得到, 具有广阔的市场前景. 综述了它的生物和化学法制备进展, 及其在药物合成方面的应用, 并展望了其制备工艺的发展趋势.     

乙酰丙酮钇催化环氧氯丙烷的均聚合与共聚合

用过渡金属络合催化剂聚合环氧氯丙烷能获高分子量的聚合物。稀土络合催化剂对环氧乙烷,环氧丙烷及环硫丙烷的开环聚合具有明显效果。本文选用Y(acac)_3-H_2O-Al(i-Bu)_3催化剂,考察环氧氯丙烷的均聚合及其与环氧乙烷,环氧丙烷的共聚合,并用核     

磷改性β沸石催化剂上催化裂化轻汽油的醚化

在小型固定床反应装置上,考察了负载磷的β沸石催化剂的制备条件对其催化性能的影响以及醚化反应温度、压力、醇烯摩尔比、LHSV对醚化反应的影响。实验结果表明,浸渍磷的质量分数为2%的Hβ催化剂具有较好的醚化活性。在最佳反应条件(温度70 ℃,压力0.8 MPa,LHSV 1.0 h-1,醇烯摩尔比1.0)下,该催化剂的叔碳烯烃的总转化率可达到56.91%。负载磷后的催化剂具有活性好、选择性高、不易失活等优点。反应性能均优于Hβ催化剂。     

饮用水中环氧氯丙烷分析方法的研究

通过比较分析饮用水中环氧氯丙烷的多种方法后,确定了以HP-FFAP毛细管色谱柱-固相萃取-FID气相色谱法测定水中环氧氯丙烷,该方法线性关系良好,灵敏度高,通过优化条件,方法的最低检出浓度为0.00025 mg/L,满足《生活饮用水卫生标准》(GB5749-2006)的要求以及实际水质检测的需求。     

液相色谱法测定环氧氯丙烷工业中间体中的己二酸

建立了液相色谱仪测定环氧氯丙烷工业中间体中己二酸含量的方法。样品采用甲醇-10mm01／L磷酸缓冲液（体积比5：95）溶液提取,C18固相萃取柱净化,紫外检测器检测,外标法定量。己二酸在100～2000mg／L范围内线性良好,相关系数大于0．9999,按10s／Ⅳ计算,己二酸定量限为25．0mg／kg。添加回收率为91．1％～112．2％．测定结果的相对标准偏差为4．7％～7．9％（n=5）。该方法简单快速,回收率高,重现性好,满足工业分析要求。     

乙酰化稻草/聚己内酯接枝共聚物的合成及表征

以稻草秸秆为原料,经粉碎后进行全植物秸秆的乙酰化改性,再用此乙酰化稻草同ε-己内酯(ε-CL)接枝共聚合成乙酰化稻草/聚己内酯接枝共聚物(ACSW-g-PCL)。研究了反应时间、反应温度、及单体用量对接枝率(G%)的影响。在反应温度140℃,反应时间10h,ε-CL对乙酰化稻草的质量比2:1时获得的接枝率最大为39%。产物的结构和性能通过红外光谱、核磁共振、扫描电镜、X-射线衍射和热分析仪表征,结果表明乙酰化稻草秸秆已成功接枝上聚己内酯(PCL)链段,经接枝ε-CL改性后的ACSW-g-PCL热稳定性有所改善,并具有了一定的热塑性。     

水稻秸秆的改性及其对重金属Cu2+的吸附

重金属Cu2+可直接或间接危害人体,作为天然吸附剂的农业废弃物因价廉易得、来源广泛、吸附高效等优点备受青睐。本文选用水稻秸秆（RS）为吸附原料,分别经酸、碱改性后得到H2SO4-RS和NaOH-RS,通过FT-IR、SEM和BET对改性前后吸附材料的表面官能团、表观形貌和结构等理化性质进行分析,考察投加量、吸附时间、初始Cu2+浓度和离子强度对吸附效果的影响,并结合吸附动力学、吸附等温线和热力学模型对吸附过程进行探讨。结果表明：改性水稻秸秆对Cu2+达到吸附平衡所需的投加量和时间较之未改性RS大大减少,去除率由42.0%分别提升至85.9%（H2SO4-RS）和90.0%（NaOH-RS）;随初始Cu2+浓度和离子强度的增大,RS的吸附性能显著降低,H2SO4-RS有所降低,而NaOH-RS只是稍有下降,NaOH-RS对150 mg/L含Cu2+溶液的去除率仍达到84.2%,离子强度cNaCl = 0.1 mol/L时去除率维持在86.1%。吸附动力学和吸附等温实验表明水稻秸秆对Cu2+的吸附符合准二级动力学模型和Langmuir吸附等温模型;热力学分析显示,相同温度下RS、H2SO4-RS和NaOH-RS吸附Cu2+过程的ΔG逐渐减小,且改性后两种吸附剂的ΔG均小于0,ΔH由改性前的正值转变为负值,说明水稻秸秆改性后吸附Cu2+的自发性更强,为自发的放热过程。     

Modification of Rice Straw for Heavy Metal Ion Adsorbents by Microwave Heating

Summary: Cellulose in rice straw was chemically modified by phosphorylation using conventional heating or microwave heating. Rice straw pretreated by NaOH solution gave the highest phosphorus content when it was phosphorylated using microwave heating at 450 watt (7.07%P, ion exchange capacity 2.60 meq/g). The 3 hour-reaction in oil bath yielded the modified rice straw with lower of phosphorus content (6.32%P) and higher ion exchange capacity (2.99 meq/g) than that of microwave heating. The feasibility of the modified rice straw as cation sorbents for removing heavy metal was investigated. Cd²⁺, Cr³⁺ and Pb²⁺ were used as sorbates. In sorption test of 40 ppm with 2.0 g/L of the modified rice straw, both modified rice straws could adsorb metal ions faster than the commercial ion exchange resin (dowax) at the time less than 60 min. The modified rice straw prepared by microwave heating (A-MCW2) could remove 90% of Cd²⁺ and Cr³⁺ in 60 minutes and remove 99% of Pb²⁺ after 30 min.     

秸秆预处理工艺对秸秆基人造板性能的影响

随着木材工业的快速发展,以及木材原料的日益减少,利用农作物秸秆代替木材生产复合材料十分必要。 本文以水稻秸秆为原料,以脲醛树脂为粘合剂,通过湿热法、偶联剂表面化学改性的方法,对秸秆表面进行改性,从而提高了树脂和秸秆之间的结合力,探索了水稻秸秆板的制作工艺。 实验表明较好的制备工艺为:温度150 ℃,压强15 MPa,热压时间8 min,树脂胶粉和水的质量比为1:1,脲醛树脂胶含量为15%(质量分数),发现秸秆表面预处理采用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)偶联剂后,所制得的秸秆板的诸多性能优于未经预处理及采用γ-氨丙基三乙氧基硅烷(KH550)进行改性后所制的秸秆板。     

Preparation and Characterization of MgO-Modified Rice Straw Biochars

Rice straw is a common agricultural waste. In order to increase the added value of rice straw and improve the performance of rice straw biochar. MgO-modified biochar (MRBC) was prepared from rice straw at different temperatures, pyrolysis time and MgCl₂ concentrations. The microstructure, chemical and crystal structure were studied using X-ray diffraction (XRD), a Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption desorption isotherms and Elementary Analysis (EA). The results showed that the pyrolysis temperature had significant influence on the structure and physicochemical property of MRBCs. MRBC-2 h has the richest microporous structure while MRBC-2 m has the richest mesoporous structure. The specific surface area (from 9.663 to 250.66 m²/g) and pore volume (from 0.042 to 0.158 cm³/g) of MRBCs increased as temperature rose from 300 to 600 °C. However, it was observed MgCl₂ concentrations and pyrolysis time had no significant influence on pore structure of MRBCs. As pyrolysis temperature increased, pH increased and more oxygen-containing functional groups and mineral salts were formed, while MgO-modified yield, volatile matter, total content of hydrogen, oxygen, nitrogen, porosity and average pore diameter decreased. In addition, MRBCs formed at high temperature showed high C content with a low O/C and H/C ratios.     

Effects of Rice Straw Powder (RSP) Size and Pretreatment on Properties of FDM 3D-Printed RSP/Poly(lactic acid) Biocomposites

To develop a new kind of environment-friendly composite filament for fused deposition modeling (FDM) 3D printing, rice straw powder (RSP)/poly(lactic acid) (PLA) biocomposites were FDM-3D-printed, and the effects of the particle size and pretreatment of RSP on the properties of RSP/PLA biocomposites were investigated. The results indicated that the 120-mesh RSP/PLA biocomposites (named 120#RSP/PLA) showed better performance than RSP/PLA biocomposites prepared with other RSP sizes. Infrared results showed that pretreatment of RSP by different methods was successful, and scanning electron microscopy indicated that composites prepared after pretreatment exhibited good interfacial compatibility due to a preferable binding force between fiber and matrix. When RSP was synergistically pretreated by alkaline and ultrasound, the composite exhibited a high tensile strength, tensile modulus, flexural strength, and flexural modulus of 58.59, 568.68, 90.32, and 3218.12 MPa, respectively, reflecting an increase of 31.19%, 16.48%, 18.75%, and 25.27%, respectively, compared with unmodified 120#RSP/PLA. Pretreatment of RSP also improved the thermal stability and hydrophobic properties, while reducing the water absorption of 120#RSP/PLA. This work is believed to provide highlights of the development of cost-effective biocomposite filaments and improvement of the properties of FDM parts.     

Valorization of Rice Straw via Hydrotropic Lignin Extraction and Its Characterization

Rice straw hydrotropic lignin was extracted from p-Toluene sulfonic acid (p-TsOH) fractionation with a different combined delignification factor (CDF). Hydrotropic lignin characterization was systematically investigated, and alkaline lignin was also studied for the contrast. Results showed that the hydrotropic rice straw lignin particle was in nanometer scopes. Compared with alkaline lignin, the hydrotropic lignin had greater molecular weight. NMR analysis showed that β-aryl ether linkage was well preserved at low severities, and the unsaturation in the side chain of hydrotropic lignin was high. H units and G units were preferentially degraded and subsequently condensed at high severity. High severity also resulted in the cleavage of part β-aryl ether linkage. ³¹P-NMR showed the decrease in aliphatic hydroxyl groups and the increasing carboxyl group content at high severity. The maximum weight loss temperature of the hydrotropic lignin was in the range of 330–350 °C, higher than the alkaline lignin, and the glass conversion temperature (T_g) of the hydrotropic lignin was in the range of 107–125 °C, lower than that of the alkaline lignin. The hydrotropic lignin has high β-aryl ether linkage content, high activity, nanoscale particle size, and low T_g, which is beneficial for its further valorization.     

水稻秸秆石油醚和乙醇萃取物的组成分析

用石油醚和乙醇在索式萃取器中对水稻秸秆进行了萃取,萃取物用傅里叶转换红外光谱仪（FTIR）和气相色谱 质谱联用仪（GC/MS）分析。 结果表明,乙醇和石油醚的萃取率分别为8%和6%。 萃取物中共检测到40种物质,主要分为醇酚（APs）、醛、酮、酸、酯、烃（HCs）及含氮化合物（ONs）7种类别。 其中,石油醚萃取物中酯、HCs和APs 3类物质含量较高,总的相对含量为91.7%;乙醇萃取物中HCs、酸、酯及APs含量较高,总的相对含量为83.9%。 该研究在开发稻秆的高附加值利用方面具有重要的基础理论意义。     

Adsorption of Hazardous Azorhodanine Dye from an Aqueous Solution Using Rice Straw Fly Ash

The potential of using rice straw fly ash (RSFA) as low-cost adsorbents for the removal of hazardous azorhodanine (AR) dye from aqueous solution was investigated. The effects of different variables in the batch method as a function of solution pH, contact time, concentration of adsorbate, adsorbent dosage, and temperature were investigated, and optimal experimental conditions were ascertained: 0.05 g for initial dye concentration of 20–100 mg/L at pH 2. The experimental equilibrium data were tested by the isotherm models, namely the Langmuir and Freundlich adsorption and the isotherm constants were determined. The kinetic models, pseudo-first-order and pseudo-second-order, were employed to analyze the kinetic data. The activation energy of adsorption was also evaluated and found to be +10.89 kJ.mol^?1, indicating that the adsorption is physisorption. Various thermodynamic parameters, such as Gibbs free energy, entropy, and enthalpy of the ongoing adsorption process, have been calculated and found to be spontaneous and exothermic, respectively.     

人纤维蛋白溶酶原中色氨酸残基的化学修饰

以Ｎ－溴代琥珀酰亚胺为修饰剂，对人纤维蛋白溶酶原（ＨＰｇ）中色氨酸（Ｔｒｐ）残基的分布及其与酶活力的关系进行了研究，发现每个ＨＰｇ分子有１９个Ｔｒｐ残基，５个位于分子表面：有２个是快反应残基，其中１个是活性必需的氨基酸，酶被修饰后其荧光光谱及圆二色谱发生了变化。