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《皮革与化工》2015,(2)
以天然淀粉为原料,以环氧氯丙烷为交联剂,制备交联淀粉,在此基础上,以GTA为醚化剂、二硫化碳为酯化剂,制备了阳离子交联淀粉黄原酸酯。实验结果表明:交联淀粉的操作工艺条件影响因素顺序为:氢氧化钠用量环氧氯丙烷用量反应时间反应温度;阳离子交联淀粉黄原酸酯的操作工艺条件影响因素顺序为:二硫化碳用量反应时间反应温度氢氧化钠用量,其最佳工艺条件为氢氧化钠加入量20 m L,反应温度40℃,二硫化碳加入量5 m L,反应时间2h。含6.0μg/m L Cr6+的模拟废水经阳离子交联淀粉黄原酸酯处理后,其最小吸光度为0.1892,此时Cr6+最大清除率可达62%以上。 相似文献
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以淀粉为原料,环氧氯丙烷为交联剂,二硫化碳为酯化剂,制备不溶性交联淀粉黄原酸酯。结果表明交联淀粉的最佳操作工艺条件为:玉米淀粉20 g、0.2 g/m L Na OH溶液5.0 m L、环氧氯丙烷4.0 m L、反应温度30℃、反应时间2.5 h。交联淀粉黄原酸酯的最佳合成工艺条件为:交联淀粉10 g,0.2 g/m L的Na OH溶液20 m L,5 m L CS2,温度50℃,反应时间1.0 h。交联淀粉黄原酸酯净化生活废水试验结果表明:在10 m L生活废水中,投加0.7 g淀粉黄原酸酯时,废水吸光度达到最小;当其他条件一定时,生活废水p H约为7、反应时间为40 min时,吸附效果较佳。 相似文献
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以天然淀粉为原料,氢氧化钠为催化剂、环氧氯丙烷为交联剂制备交联淀粉,以制备得到的交联淀粉为原料、2,3-环氧丙基三甲基氯化铵为醚化剂,采用微波辅助半干法制备交联醚化淀粉,在此基础上,以交联醚化淀粉为原料,二硫化碳为酯化剂,在碱性条件下制备阳离子交联淀粉黄原酸酯。实验结果表明,制备阳离子交联淀粉黄原酸酯的最佳工艺参数为:Na OH的加入量为24 m L,二硫化碳用量7 m L,反应温度为50℃,反应时间2.5 h。 相似文献
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环氧氯丙烷交联淀粉的制备及其体外消化性能的研究 总被引:1,自引:0,他引:1
以环氧氯丙烷为交联剂,制备土豆交联淀粉。用正交实验考察环氧氯丙烷用量、氢氧化钠用量、反应温度和反应时间四个因素对交联度的影响,确定最佳工艺条件,并对体外消化条件进行优化,对不同交联度淀粉的消化速度进行研究。体外淀粉消化条件的优化实验显示,消化产物测定的最佳条件为:波长485nm,显色温度100℃,显色时间30min,葡萄糖浓度范围0~80μg/mL,其回归方程为y=0.0044x-0.005,R2=0.9988,且样品溶液在2h内显色稳定。各因素对交联淀粉制备影响的重要性依次为环氧氯丙烷用量、氢氧化钠用量、温度及反应时间;最佳工艺条件为:以50g土豆淀粉计,环氧氯丙烷用量为1.00mL,氢氧化钠用量为0.75g,温度50℃,时间6h,土豆交联淀粉和交联前相比,消化性降低了13.7%~34.5%,且与交联度呈负相关。 相似文献
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以羧甲基玉米淀粉为原料,环氧氯丙烷为交联改性剂,乙醇溶液为反应介质,通过四因素二次正交旋转组合试验设计和响应面分析,得出羧甲基玉米淀粉交联改性的回归模型.结果表明,交联改性最佳工艺参数为反应温度53.2℃,环氧氯丙烷用量0.23%(占淀粉干基),反应时间64.6 min,pH值10,改性淀粉表现黏度可达10.51 Pa.s,较玉米淀粉和数甲基淀粉表现黏度分别提高了214.67%和88.35%.环氧氟丙烷用量对改性淀粉表现黏度的影响最显著(P(0.01);反应温度与pH值之间、环氧氯丙烷用量与pH值之间存在极显著的交互作用(P(0.01). 相似文献
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Joana Bendoraitiene Rasa Kavaliauskaite Rima Klimaviciute Algirdas Zemaitaitis 《Starch - St?rke》2006,58(12):623-631
Cationic starch derivatives containing quaternary ammonium groups with high degree of substitution are prepared by reaction of starch with glycidyltrimethylammonium chloride (GTAC) in different reaction media. In aqueous solutions of GTAC along with conventional hydrolysis of epoxy groups, their interaction with chloride ions also takes place. This resulted in formation of hydroxyl ions which accelerate both the hydrolysis of GTAC epoxy groups and can act as the internal catalyst in the reaction of GTAC with starch. Therefore, even in the absence of the external catalyst, cationic starch with a high degree of substitution can be obtained. The autocatalytic reaction of GTAC with starch proceeds more rapidly at higher temperatures but with lower reaction efficiency. Both in the absence of the external catalyst and in the case when sodium alkali is used as a catalyst the reaction of starch with GTAC proceeds only when a particular quantity of “free” water is present in the system. When the NaOH as catalyst is used the reaction efficiency is about 90%. The yield of starch cationization reaction decreases when the quantity of “free” water is twice or thrice higher than required for starch modification to begin. 相似文献
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实验利用水溶剂法,以普通阳离子淀粉(CS)、二甲基二烯丙基氯化铵单体(DADMAC)、铝溶胶为原料,硝酸铈铵(CAN)为引发剂,制备了铝铵基阳离子淀粉(ACS)。研究了引发剂用量、单体用量、反应温度、反应时间等对接枝反应的影响。研究发现最佳的反应条件为:引发剂用量为0.54%,单体用量为50%,铝溶胶加入量为3.5%,反应温度为55℃,反应时间为3 h,m(H2O)∶m(St)=2∶1,可制得氮含量约为0.58%的ACS,高于普通的阳离子淀粉CS(0.30%)。用紫外分光光度法测定产品的铝含量并采用红外光谱对接枝共聚物进行了结构分析。将铝铵基阳离子淀粉应用于脱墨浆中,最低白水浊度为5.2 NTU;最高灰分含量为23.27%。在用量低于0.5%时,能同时提高纸张的强度和细小纤维的留着率,具有助留和增强的双重作用。通过在浆中加入相同量的ACS和CS进行比较,发现ACS的絮凝作用和助留效果均优于CS。 相似文献
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以3-氯-2-羟丙基三甲基氯化铵为醚化剂,采用微波半干法制备了低黏度阳离子氧化木薯淀粉,研究了醚化剂用量、氢氧化钠用量、乙醇用量、反应温度和反应时间对反应的影响,并对产品乳化AKD的性能进行了研究。研究结果表明,最佳反应条件为:醚化剂用量53%、氢氧化钠用量14%、醚化剂与氢氧化钠摩尔比1:1,并用氢氧化钠与乙醇配制成质量分数为8%的溶液,体系含水量为18.5%,反应温度为60℃,反应时间3h,产品取代度达到0.3906,反应效率85.53%。所得产品对AKD具有良好的乳化性能。 相似文献
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为了提升淀粉基仿生谷胱甘肽过氧化物酶(GPx)的催化活力,采用木薯淀粉(CS)制备的硒化淀粉(SCS)和阳离子淀粉(CCS)进行混合,获得含催化中心和底物识别位点的目标淀粉(SCS/CCS)。首先,采用辛烯基琥珀酸酐、硒氢化钠和2,3-环氧丙基三甲基氯化铵分别对CS进行改性制备SCS和CCS;通过核磁共振波谱仪(1H NMR)、傅里叶变换红外光谱仪(FT-IR)、X射线衍射仪(XRD)、同步热分析仪(TG)和扫描电子显微镜(SEM)等手段对改性后的样品进行表征;最后以氮和硒物质的量比为变量,考察SCS与CCS的混合对GPx催化活力的影响。结果表明,与CS相比,硒含量为11.35 μg/g的SCS的1H NMR图谱在化学位移0.6~2.5之间出现了辛烯基琥珀酸酯分子链上质子的信号峰;SCS的FT-IR谱图与CS FT-IR谱图相似,但羟基(3300 cm?1)和结合水(1639 cm?1)特征峰的强度降低,表明SCS的合成过程消耗了CS骨架上的羟基,并提高了CS的疏水性;CCS的1H NMR图谱上3.22 ppm处出现季铵基的特征峰,同时,CCS的FT-IR谱图在1483 cm?1处出现了归因于季铵基C?N拉伸振动的特征峰,表明阳离子基团季铵基已成功修饰于CCS骨架上;与CS相比,SCS和CCS的颗粒形状无明显变化,但颗粒表面粗糙,表明改性反应主要发生在淀粉颗粒的表面;CS、SCS和CCS的XRD花样和失重曲线无明显差别,说明反应未显著影响淀粉的结晶结构和热稳定性。当SCS/CCS中氮和硒物质的量比为1200时,其在4-硝基苯硫酚+枯烯过氧化氢(NBT+CUOOH)、3-羧基-4硝基苯硫酚+氧化氢(TNB+H2O2)、NBT+CUOOH和NBT+H2O2反应体系中的GPx催化活力分别为13.94、11.25、12.91、10.87 μmol/min,比SCS分别提高了22.1%、25.8%、17.5%、19.6%。本研究为构建高催化活性的淀粉基仿生GPx提供了简单方法。 相似文献
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Saiyavit Varavinit Worachat Paisanjit Tuangporn Tukomane Chirdchan Pukkahuta 《Starch - St?rke》2007,59(6):290-296
Tapioca starch was crosslinked with 0.1 % sodium trimetaphosphate (STMP) in the presence of alkali and of osmotic pressure enhancing salts such as sodium sulfate and sodium chloride. The addition of various percentages of sodium sulfate to the crosslinking reaction mixture changed the pasting properties of the product starch as measured in the RVA (Rapid Visco Analyser). Peak viscosity (PV) and final viscosity (FV) are first increased with the increase in osmotic pressure followed by a decrease of the viscosities after further pressure increase. Breakdown (BD) is decreased in line with the increase of the osmotic pressure with very good correlation (R2 = 0.96). These pasting characteristics are attributed to the inhibited swelling without disruption of the starch granules due to the crosslinking reaction. If sodium chloride is used as an osmotic pressure enhancer of the crosslinking reaction, both pasting properties (PV, FV) decrease linearly with the increase in osmotic pressure with very good correlation (R2 = 0.98 and 0.99, respectively). The BD is dramatically decreased to zero (no breakdown) after applying the osmotic pressure and remains zero after further increase in osmotic pressure. These properties are also attributed to the pasting characteristics of the crosslinked starch. The increase in pasting temperature (PT) with increasing osmotic pressure for both sodium sulfate and sodium chloride demonstrates the increase of the gelatinization temperature of the starch granules. The enhancement of the osmotic pressure can promote the activity of the crosslinking agent. 相似文献
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Cross‐linked N‐(hydroxypropyl)–N,N,N–trimethylammonium starch chlorides (CQS) with preserved microgranules, degree of substitution (DS) from 0.18 to 1.05 are prepared by reaction of starch with glycidyltrimethylammonium chloride (GTAC) accelerated by benzyltrimethylammonium hydroxide (BTMAOH) or tertiary amines–triethylamine (TEA) and dimethylbenzylamine (DMBA). When BTMAOH instead of NaOH is used as a catalyst, the reaction of cross‐linked starch (CS) with GTAC proceeds slightly slower and with a lower efficiency (RE). DMBA unexpectedly showed similar catalyst efficiency as BTMAOH. It is suggested that the reason for such phenomena is the reaction of GTAC with tertiary amines and the formation of strong bases – quaternary ammonium hydroxides. They actually catalyse starch cationization. DMBA is more active in this reaction in comparison with TEA. It is shown that, due to a higher amount of quaternary ammonium hydroxides in the liquid phase of the reaction mixture, the yield of starch cationization decreases. Cationization in the presence of organic bases provides higher sorption capabilities to the modified polysaccharide. 相似文献