交联壳聚糖用作种衣剂中成膜剂的研究

采用不同用量的戊二醛(0%、1.5%、3.0%、6.0%、9.0%)作为交联剂,对不同质量浓度的壳聚糖溶液(1.0%、1.5%、2.0%、2.5%)进行不同程度交联,探索交联壳聚糖溶液的成膜性能和包衣性能及其对玉米种子发芽率的影响。结果表明,交联壳聚糖成膜性能和包衣性能得到明显改善,2.0wt.%-1.5%(即壳聚糖质量浓度2.0%,戊二醛交联剂用量1.5%)样品的成膜时间为9.6 min,包衣脱落率为8.4%,包衣均匀度为91.8%,发芽率为93%。

甲基磺酸体系电刷镀锡及其在电力设备表面修复中的应用

对铜基体电刷镀锡,镀液组成和工艺条件为:硫酸亚锡20g/L,甲基磺酸55g/L,乙二胺四乙酸5g/L,硫酸铵110g/L,自制添加剂75mL/L,正接,电压6.5~8.0V,室温,镀笔速率5cm/s,刷镀5~10次。该镀液稳定,其电导率能保持至少15d。所得电刷镀锡层结晶均匀、致密,结合力好,厚度可大于20μm,满足电力系统中大型不解体设备表面修复的实际需求。

Effect of Molecular Weight and Structure on Antitumor Activity of Oxidized Chitosan

Various low molecular weight chitosans were prepared by oxidative degradation with H2O2, and characterized by IR,13C-NMR and gel permeation chromatography. Their carboxylic contents increased with decrease in molecular weight (M w ). The antitumor test of the samples against sarcoma 180 tumors suggested that the water-soluble chitosan with higherM w have higher inhibitory ratioin vivo. The introduction of carboxylic group is advantage to water-solubility of chitosan, but more acidic groups might decrease the function of amino groups of chitosan against sarcoma 180 tumor.