Reinforcing Paper Strength by Dual Treatment of a Cationic Water-soluble Polymer and Cellulose Nanofibril

Cellulose nanofibril (CNF) was used as the anionic component of two dual strengthening systems wherein polyamidopolyamine epichlorohydrin resin (PAE) or cationic starch (CS) was used as the cationic component. Their strengthening effects were investigated for low-basis-weight (30 g/m²) paper composed of a mixture of fully bleached softwood and hardwood pulp in a 4:1 mass ratio. Using the PAE/CNF or CS/CNF dual system, it was generally easier to achieve higher wet and dry tensile strengths of paper compared to the paper using the single PAE or CS system. For example, the paper using the PAE (0.4%)/CNF (0.3%) dual system exhibited 89% higher wet tensile strength than the paper using the single PAE (0.4%) system, and the paper using CS (1.3%)/CNF (0.3%) dual treatment showed 21% higher dry strength than that using the single CS (1.3%) system. However, the PAE/CNF system only showed small improvement in the dry strength of paper (11% higher than that of paper using the single PAE system), so did the CS/NFC system on wet strength improvement (only 17% higher than that of paper using the single CS system).     

响应曲面法优化(salen)Co(Ⅲ)(OAc)拆分手性环氧氯丙烷的制备工艺

以(salen)Co(Ⅲ)(Oac)为催化剂不对称选择性水解制备手性环氧氯丙烷,采用响应曲面法中的Box-Behnken设计对影响手性环氧氯丙烷光学纯度的4个主要因素(反应温度、水用量、催化剂用量、反应时间)进行优化,建立手性环氧氯丙烷光学纯度的二次多项回归模型方程,并对回归系数进行显著性检验和方差分析。实验结果表明,当反应温度为46.02℃、水与环氧氯丙烷的摩尔比为61.10、催化剂与环氧氯丙烷的摩尔比为0.003937、反应时间为18h时手性环氧氯丙烷的光学纯度最高,最高光学纯度预测值为102.18%,与实测平均值99.61%基本相符,优化模型有效可靠。     

Characteristics of cotton fabrics treated with epichlorohydrin and chitosan

Cotton fabrics treated with a crosslinking agent, epicholorohydrin, in the presence of chitosan (CEC) provide many possible reactive sites for reactive dyes and antimicrobial properties of the grafted chitosan to the cellulose structure. This process was applied by means of the conventional mercerizing process. The chitosan finishing and durable press finishing of the cotton fabrics occurred simultaneously in the mercerization bath. ECH is expected to react with hydroxyl groups in cellulose and chitosan or with amino groups in chitosan to form alcohol crosslinking by the Belfast process. The fixed chitosan content in the CEC was calculated by the nitrogen percentage of an Elemental Analyzer. The color strength (K/S) of the reactive dyes of the treated cotton fabrics did not significantly change with an increase of chitosan; however, the degree of swelling of the treated cotton fabrics decreased with an increase of chitosan and ECH. These performances were retained through 20 washing and tumble drying cycles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

环氧氯丙烷交联海藻酸钠纤维的制备及其性能

为提高海藻酸钠纤维的断裂强度,采用环氧氯丙烷先改性海藻酸钠,并用湿法纺丝法制备改性海藻酸钠纤维。将制备的改性海藻酸钠纤维经过100 ℃烘干使之进一步发生交联反应。烘干后的改性海藻酸钠纤维浸泡在质量分数为0.4% NaCl溶液中以脱去部分与海藻酸钠交联的钙离子。结果表明,经过烘干和浸泡NaCl溶液处理的改性海藻酸钠纤维断裂强度最高可达15.9 cN /tex,比未经烘干和浸泡NaCl溶液处理的改性海藻酸钠纤维断裂强度高59%,比纯海藻酸钠纤维断裂强度高42.9%。FT-IR谱图在1256 cm-1处增加了环氧氯丙烷的三元环醚特征吸收峰,723 cm-1处增加了环氧氯丙烷的-C-Cl特征吸收峰,表明环氧氯丙烷与海藻酸钠发生交联反应。SEM和XPS分析结果表明,通过浸泡NaCl溶液,部分钙离子从纤维中脱去,纤维表面逐渐变得光滑均匀。     

聚酰胺环氧氯丙烷增强聚丙烯腈纤维纸的研究

将聚酰胺环氧氯丙烷(PAE)树脂用于聚丙烯腈(PAN)纤维湿法纸张成形过程,以提高纸张强度性能。PAE树脂通过在PAN纤维上附着沉积形成自交联网络,增强纤维间结合。当PAE树脂的用量为0.6%(相对纤维绝干量)时,纸张抗张指数提高21.0%,撕裂指数提高25.8%,伸长率提高34.4%,紧度提高8.2%。通过衰减全反射-傅里叶红外光谱仪(ATR-FTIR)、X射线光电子能谱仪(XPS)及扫描电子显微镜(SEM)分析,证实了PAE树脂分子间通过自交联网络结构,形成叔胺基团,使纤维间结合更为紧密,因而提高纸张的紧度和强度。本研究提出了一种制备具有优异强度性能的PAN纤维纸的方法。     

Preparation of trypsin‐immobilised chitosan beads and their application to the purification of soybean trypsin inhibitor

BACKGROUND: Trypsin inhibitors are among the most important antinutritional factors in legumes. Recent research has shown that soybean trypsin inhibitor (SBTI) exhibits multiple bioactivities, but very few studies on the purification of SBTI are available. Enzymes are commonly used as biospecific ligands in affinity purification of their substrates or inhibitors. The aim of the present study was to prepare trypsin (EC 3.4.21.4)‐immobilised chitosan beads and use them to purify trypsin inhibitor from soybean whey. RESULTS: Compared with free trypsin, the immobilised trypsin had higher thermal and pH stability. The adsorption ratio of SBTI from crude SBTI aqueous solution by trypsin‐immobilised chitosan beads was 33.3%. The purified SBTI obtained by affinity chromatography was characterised by sodium dodecyl sulfate polyacrylamide gel electrophoresis as a single polypeptide band with an M_r of 8.3 kDa belonging to the Bowman–Birk family. CONCLUSION: Trypsin‐immobilised chitosan beads were effectively used in the affinity separation of trypsin inhibitor from soybean seeds, thus indicating that immobilised trypsin may have practical application in the soybean‐processing industry. The results of this study provide a background for further investigation of potential applications of soybean bioactive constituents in the areas of agriculture and food. Copyright © 2008 Society of Chemical Industry     

一种新的均三嗪类紫外线吸收剂ZLG-1的合成及表征

以三聚氯氰、间二甲苯为原料,经过Friedel-Craft反应,合成了2-氯-4,6-二（2＇,4＇二甲基苯基）-1,3,5-均三嗪（Ⅰ）,化合物Ⅰ在三氯化铝作用下再与间苯二酚反应,得到了2-（2’,4＇-二羟苯基）-4,6-二（2”,4”-二甲基苯基）-1,3,5-均三嗪（Ⅱ）．化合物Ⅱ在碱性条件下与环氧氯丙烷缩合并水解得到了该均三嗪类的紫外线吸收剂2-[2’-羟基-4’-（2＇＇＇,3＇＇＇）-二羟基丙烷氧基苯基]-4,6-二（2”,4”）-二甲基苯基-1,3,5-均三嗪（ZLG-1）,总收率为61．8％．讨论了反应温度、时间及反应物配比对各步反应收率的影响;并对化合物Ⅱ和ZLG-1的结构用IR、^1HNMR、MS进行了表征．由ZLG-1的UV光谱数据表明其紫外线吸收性能和三嗪-425相当．     

阴离子型淀粉微球的制备研究

本文先以可溶性淀粉为原料,以表氯醇为交联剂,采用逆相悬浮交联聚合法制得中性淀粉微球,然后用Na3P3O9作交联剂进行第二次交联和阴离子化,制得阴离子型淀粉微球。分析了不同因素对中性淀粉微球的粒径及其分布的影响,优化了制备的工艺条件。对产品的物理化学性质进行了表征。实验结果表明:此制备工艺稳定,有良好的应用研究前景。     

生物柴油副产物甘油深加工的研究现状

本文就生物柴油副产物甘油深加工制备1,3-丙二醇、 1,2-丙二醇、环氧氯丙烷、甘油酯等重要衍生物过程的研究进展加以综述,为甘油进一步深加工提供理论基础。     

新型阻燃剂磷酸二-(2,3-二氯丙基)酯三聚氰胺盐的合成

以三氯氧磷 ,环氧氯丙烷和三聚氰胺为原料合成了一种新型含氮、磷和氯的阻燃剂磷酸二 ( 2 ,3二氯丙基 )酯三聚氰胺盐 ,并研究了反应物配比 ,催化剂用量、反应温度以及中间体的处理方法对产品收率的影响。结果发现反应适宜条件为三氯氧磷∶环氧氯丙烷和三聚氰胺的摩尔比为 1∶ 2∶ 1 ,第一步反应为 6 0～70℃ ,第二步反应为 1 0 0℃ ,产品收率 82 %。其含氮量为 2 1 .75% ,含磷量为 6 .1 9%。