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1.
超声提取-反相高效液相色谱法测定棉仁中游离棉酚   总被引:1,自引:0,他引:1  
用超声提取对棉仁进行预处理,探讨了影响棉酚提取率的因素,确定其最佳提取条件为:料液比0.1∶15(g/mL),提取时间50min,超声功率90W。在最佳提取条件下,棉仁中游离棉酚的平均提取率为6.3282 mg/g。利用反相高效液相色谱(RP-HPLC)法测定棉仁中游离棉酚含量,使用SinoChrom ODS-BP C18色谱柱(200×4.6mm,5μm),流动相为甲醇-1%磷酸水溶液(体积比85∶15),流速为0.9mL/min,紫外检测波长为238nm。结果表明,棉酚在0.0044~0.0352mg/mL范围内与色谱峰面积呈良好线性关系,线性相关系数为0.9998,平均加标回收率在98.80%~99.03%之间。该法快速、灵敏、准确,适用于棉仁中游离棉酚的定量分析。  相似文献   

2.
磷改性β沸石催化剂上催化裂化轻汽油的醚化   总被引:4,自引:1,他引:4  
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。  相似文献   

3.
以香茅醇为原料、制备的介孔Cu/SiO_2为催化剂,在固定床反应器中对一步法催化香茅醇合成香茅腈进行了研究。采用气象色谱、红外光谱和质谱对反应产物进行了定性定量分析。考察了反应温度、氨醇摩尔比和原料空速(WHSV)对反应的影响。实验结果显示,以Cu/SiO_2为催化剂,反应温度270℃、0.1MPa、氨醇摩尔比4.5和原料空速1.24 h~(-1)时,反应转化率达到99.52%,香茅腈选择性达89.66%。并在最佳反应条件下,对Cu/SiO_2催化剂的稳定性进行了研究,实验表明,400h后催化剂失活。  相似文献   

4.
以浓硫酸为催化剂,对尼龙66(PA66)甲醇醇解反应进行了研究。采用红外光谱(FT-IR)和核磁共振技术(1 H NMR)对醇解产物进行了表征,并确认醇解产物为己二酸二甲酯(DMA)和己二胺(HMD)。采用L_9(3~4)正交实验方法,考察了反应温度、反应时间、催化剂用量及甲醇用量等因素对醇解反应结果的影响,并获得较佳工艺条件为:PA66和硫酸的摩尔比1∶2;PA66和甲醇的摩尔比1∶20;反应温度为120℃;反应时间为5h。在此工艺条件下,PA66转化率为100%,DMA和HMD的收率分别达到86.04%和88.62%。  相似文献   

5.
杨伟华  项时康 《色谱》1995,13(4):264-266
利用L-苯基丙胺醇与样品中的左旋(一)棉酚和右旋(+)棉酚充分反应以后,对生成的两种棉酚衍生物进行高效液相色谱分析。该方法以WatersμBondapakC_(18)色谱柱为固定相,甲醇-磷酸水溶液为流动用,获得了良好的分离效果。  相似文献   

6.
张天永  杜晶  李彬  王晓 《应用化学》2013,30(5):500-505
研究了在乙酸中,用H2O2氧化1-萘胺合成1,4-萘醌的新方法。 考察了反应温度、反应时间、1-萘胺与H2O2摩尔比、硫酸和H2O2质量分数等因素对产品收率的影响。 得到较优的反应条件为:1-萘胺与H2O2摩尔比为1∶10、H2O2质量分数为5%、硫酸质量分数为45%、反应温度为80 ℃、反应时间为3 h。 在此条件下,1,4-萘醌的收率为52.2%。 该方法具有操作简单、反应时间短和产物易分离等优点。  相似文献   

7.
废茶油的精制及其合成生物柴油的研究   总被引:1,自引:0,他引:1  
本文以废茶油为原料,经过脱胶脱酸等预处理后与甲醇进行酯交换反应制取生物柴油.探讨了反应时间、反应温度、醇-油摩尔比和催化剂用量等因素对废茶油-甲醇酯交换反应的影响,并且采用正交实验优化合成条件,确定了反应的最佳操作条件以及影响反应的关键因素.研究结果表明,酯交换反应进行的最佳反应条件为:醇油摩尔比为25:1、催化剂用量为油重的1.0%、反应时间为30min、反应温度为60℃,茶油酸甲酯产率77.34%.  相似文献   

8.
ZnMn2O4纳米催化剂制备及催化合成乙酸正丁酯   总被引:4,自引:0,他引:4  
杨则恒  桂斌  周晨旭  刘腾 《应用化学》2009,26(11):1315-1319
本文以共沉淀法制备了四方晶系锌锰复合氧化物ZnMn2O4纳米催化剂。采用X射线粉末衍射(XRD)和透射电子显微镜(TEM)测试技术对样品进行了分析表征,结果表明所合成的催化剂为粒径均匀的纳米粒子,平均粒径在20-50 nm,具有较好的分散性。实验考察了所制备的ZnMn2O4纳米催化剂对乙酸和正丁醇酯化反应的催化活性,表明ZnMn2O4对乙酸正丁酯的合成有较高的催化活性;探讨了催化剂焙烧温度、催化剂用量、酸醇摩尔比以及反应时间对酯化率的影响,确定了适宜的酯化反应条件,以焙烧温度为300 ℃制备的ZnMn2O4为催化剂,在催化剂用量为0.3%(以反应物总质量计)、酸醇摩尔比n(酸):n(醇)=1.8:1、反应时间为4 h、酯化反应温度120 ℃的条件下,酯化率可达92.53%。  相似文献   

9.
研究了以3-辛基-1-甲基咪唑四氟硼酸盐离子液体(C_8mimBF_4)为萃取剂,磷钨酸(H_3PW_(12)O_(40))为催化剂,质量分数为30%的过氧化氢(H_2O_2)为氧化剂,将模拟油中的特征硫化物苯并噻吩(BT)氧化成相应砜类物质的萃取催化氧化脱硫(ECODS)过程。通过正交试验确定其最佳反应条件:反应温度40℃、氧硫摩尔比8:1、H_3PW_(12)O_(40)与硫摩尔比8:100、萃取剂与模拟油体积比1:10、反应时间60min,在此条件下BT模拟油的脱硫率可达95.72%。同时在最佳反应条件下考察了该ECODS体系对其他类型硫化物为底物的模拟油的脱硫性能,实验结果表明几乎可以完全除去二苯并噻吩(DBT)和4,6-二甲基二苯并噻吩(4,6-DMDBT)。由正交试验极差可知,各因素对BT模拟油ECODS影响的优先顺序为:催化剂用量反应时间反应温度氧硫摩尔比剂油比。动力学实验结果表明BT氧化符合拟一级动力学模型,并计算了反应速率常数和半衰期。  相似文献   

10.
以原位酸树脂为催化剂合成了丙烯酸高碳烷基酯。探讨了酸醇摩尔比、催化剂用量、阻聚剂对苯二酚用量、反应温度、反应时间等对反应产物收率的影响。结果表明,高碳烷基醇与丙烯酸摩尔比1:1.2,催化剂和阻聚剂用量分别为高碳烷基醇质量的5.0%和0.8%,反应温度为140℃,反应时间为6h,产物收率为90.0%~97.0%,产物纯度为92.00%~98.00%。催化剂经甲醇活化,循环使用5次后产品收率为75.0%。该研究为丙烯酸高碳烷基酯的合成提供了一种新的方法。  相似文献   

11.
Recently, there has been an increasing trend toward replacing conventional fossil-based plastics with bioplastics that are eco-friendly and biodegradable. In this work, blends of polycaprolactone (PCL) and cottonseed protein plasticized with cottonseed oil were made and analyzed for their mechanical, adhesive, and thermal properties. The addition of water-washed cottonseed meal (WCSM) to PCL increased the Young’s modulus but decreased the tensile strength and elongation-at-break of PCL. The addition of cottonseed oil to the PCL/WCSM blend kept the tensile strength about the same but enhanced the elongation. The PCL blends with WCSM and cottonseed protein isolate gave about the same mechanical properties, both somewhat better than the PCL/soy protein isolate blend. As plasticizers, cottonseed oil performed slightly better than coconut oil, both better than poly(ethylene glycol). The addition of WCSM and cottonseed oil (up to a PCL:WCSM:plasticizer ratio of 60:40:20) did not change the adhesive performance of PCL on fiberboard. Thus, the combination of PCL/cottonseed protein/cottonseed oil seems to be a viable bioplastic, and one possible application for this material may be in the hot melt adhesive area.  相似文献   

12.
双核碱性离子液体催化棉籽油酯交换制备生物柴油   总被引:14,自引:2,他引:12  
采用两步法制备了五种新型咪唑类碱性双核功能化离子液体化合物,并考察了对棉籽油酯交换制备生物柴油的催化性能。结果表明,咪唑类碱性双核功能化离子液体具有很好的催化活性,其催化活性与阳离子中碳链长度有关。其中,双-(3-甲基-1-咪唑)亚乙基双氢氧化物离子液体的催化活性最好。催化剂量、反应时间、反应温度及醇油比对生物柴油中脂肪酸甲酯含量及选择性影响的研究发现,在催化剂用量为0.4%(质量分数),醇油摩尔比为12,反应温度为55℃,反应时间为4 h时,脂肪酸甲酯的含量和选择性分别达98.5%和99.9%。催化剂7次循环后,产物中脂肪酸甲酯含量仍达到96.2%,单甘酯和双甘酯的含量很少,表明该催化剂重复使用良好。  相似文献   

13.
An eco‐friendly coating system, which is largely biobased, has been developed from castor and cottonseed oil. Cottonseed oil was functionalized with maleic anhydride by “ene” reaction to give maleinized cottonseed oil (MACSO); the anhydride groups were reacted with isocyanates to yield –NCO terminated polyurethane prepolymer. The prepolymer was further chain extended with hydroxyl groups of castor oil to give polyurethane‐imides (PUIs). The cross‐linked films thus obtained had good mechanical properties, and the imide groups in the backbone improved the corrosion resistance of PUIs as revealed by potentiodynamic polarization study. With increasing content of MACSO, thermal stability, glass transition temperatures (Tg), tensile strength, and corrosion resistance of resulting PUIs significantly increased.  相似文献   

14.
邱若风  黄忠平  王丽丽 《色谱》2018,36(9):925-930
建立了分析棉籽仁中脂肪酸组成的在线热辅助甲基化-气相色谱法。将0.3 mg棉籽仁样品与2 μ L三甲基氢氧化硫(0.2 mol/L)加入裂解器,在350℃下进行甲基化反应,通过气相色谱仪进行分离分析,共检测到8种脂肪酸甲酯成分,分别为亚油酸(C18:2)、油酸(C18:1)、棕榈酸(C16:0)、硬脂酸(C18:0)、肉豆蔻酸(C14:0)、棕榈油酸(C16:1)、花生酸(C20:0)和二十二酸(C22:0),不饱和脂肪酸的相对含量为66.30%~72.54%,其中亚油酸的相对含量为43.20%~53.61%,相对峰面积的相对标准偏差(RSD)小于10%(n=5)。通过分析5组棉籽仁样品与3种食用油中的脂肪酸组成,结果表明不同产地的棉籽仁中的脂肪酸组成差异不明显,且棉籽仁中的脂肪酸组成与玉米油最为接近,相似度为0.960~0.992。该方法简单、快速、准确,适合分析棉籽仁中的脂肪酸组成。  相似文献   

15.
The solubility of raffinose in various solvents has been studied. The influence of several factors on the process of extracting raffinose from cottonseed meal has been investigated. The optimum conditions of the extraction process have been established.  相似文献   

16.
Lu Y  Weng L  Cao X 《Macromolecular bioscience》2005,5(11):1101-1107
Environmentally friendly starch biocomposites were successfully developed using a colloidal suspension of cottonseed linter cellulose crystallite as a filler to reinforce glycerol plasticized starch (PS). The cellulose crystallites, having lengths of 350 +/- 70 nm and diameters of 40 +/- 8 nm on average, were prepared from cottonseed linters by acid hydrolysis. The dependence of morphology and properties of the PS-based biocomposites on cellulose crystallites content in the range from 0 to 30 wt.-% was investigated by scanning electron microscopy, differential scanning thermal analysis, dynamic mechanical thermal analysis, and measurements of mechanical properties and water absorption. The results indicate that the strong interactions between fillers and between the filler and PS matrix play a key role in reinforcing the resulting composites. The PS/cellulose crystallite composites, conditioned at 50% relative humidity, undergo an increase in both tensile strength and Young's modulus from 2.5 MPa for PS film to 7.8 MPa and from 36 MPa for PS film to 301 MPa. Further, incorporating cottonseed linter cellulose crystallites into PS matrix leads to an improvement in water resistance for the resulting biocomposites. The mechanical behaviors of the starch-based biocomposites as a function of cellulose crystallites content.  相似文献   

17.
The solubility of raffinose in various solvents has been studied. The influence of several factors on the process of extracting raffinose from cottonseed meal has been investigated. The optimum conditions of the extraction process have been established.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 695–698, November–December, 1984.  相似文献   

18.
A chromatographic method is proposed for the quantitative determination of raffinose in cottonseed meal. The relative error of a single determination is ±4.0%.  相似文献   

19.
The qualitative and quantitative compositions of the phospholipids isolated from industrial cottonseed meal have been studied. The meal contains a mixture of phospholipids that may be a source for the production of individual phospholipids. The total and position distributions of the fatty acid radicals in individual phospholipids have been determined.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 698–700, November–December, 1983.  相似文献   

20.
Summary The optimum conditions for the drying of phytin from cottonseed meal have been determined.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 767–769, November-December, 1978. Original article submitted June 30, 1978.  相似文献   

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