【作者】 陈芳；

【导师】 杜先锋；

【作者基本信息】 安徽农业大学 ， 农产品加工与贮藏， 2009， 硕士

【摘要】 近年来阳离子型淀粉接枝产物由于将阳离子淀粉和淀粉接枝产物的优点集于一身而受到人们的重视。本文在研究了淀粉接枝丙烯酰胺的基础上研究了阳离子淀粉接枝物。将糊化淀粉和丙烯酰胺混和,配成水溶液,采用60Coγ射线下共辐照的方法制备出了淀粉与丙烯酰胺的接枝共聚物。并使用两种方法对其阳离子化,对影响反应条件的各因素进行了研究。最后应用阳离子型接枝聚合物作为絮凝剂,在污泥水处理方面进行了研究。对其结构进行定性分析由红外光谱得出其中波数在1668cm-1左右的吸收峰为共聚物中酰胺基的特征吸收峰,而波数在1546cm-1附近的强吸收峰为仲酰胺即-CO-NH-的N-H变形振动吸收峰。因此,FTIR分析证实了淀粉丙烯酰胺接枝物经阳离子改性后,分子中存在-CO-NH-CH2-N(CH3)2。而由电镜图可以看出淀粉接枝物的表面是一种凸凹不平,多毛状的,卷曲疏松形,整体呈紧密包埋状态的粒状结构,阳离子化的淀粉接枝物表面要较阳离子化之前要更加卷曲松形,呈紧密包埋状态的粒状结构表面积也更大。由此,可知作为接枝物骨架的淀粉结合了大量的丙烯酰胺支链,丙烯酰胺的柔性链和淀粉的刚性链相互渗透,相互结合,形成空间网状结构,对悬浮物的吸附能力、扑捉能力都大大提高。通过单因素实验,分别研究了辐照剂量、反应温、淀粉与丙烯酰胺配比对接枝共聚率的影响。在此基础上进行三因素三水平正交试验对关键影响因子(辐照剂量、反应温、淀粉与丙烯酰胺配比)进行优化,以接枝率为指标结合考虑成本因素确定最优制备工艺条件为:吸收剂量10kGy,淀粉:单体=1:2,温度30℃。在用辐照方法进行阳离子化反应时,通过单因素实验,分别研究了NaOH,水分,醚化剂对阳离子度的影响。在此基础上进行三因素三水平正交试验对参数进行优化,以阳离子度为指标结合考虑成本因素确定最优制备工艺条件为:醚化剂30g,NaOH量0.3g,体系水分用量30ml。在与三种絮凝剂使用效果对比实验中得出pH值对阳离子型淀粉接枝型絮凝剂絮凝效果影响不大,但对聚丙烯酰胺型絮凝剂影响较大,聚合氯化铝型絮凝剂的投料量比较大时才表现良好的絮凝效果。淀粉接枝型絮凝剂最佳投料量为450mg/L,聚丙烯酰胺和聚合氯化铝的最佳用量是600mg/L左右。更多还原

【Abstract】 For the last few years. Grafting derivations with cation group will become widely used in the future because it possesses the properties of the starch-grafting-polyacrylamide and the preparation for cationic starch by semi-dry state process, thesis focuses on the research of cationic starch with vinyl group.Gelatinous starch was mixed with acrylamide to crank out water solusion. 60Coγ-ray mutual radiation induced graft copolymerization of corn starch with acrylamide,and work out grafting yield. And the use of two methods of its cation, the impact of reaction conditions on the various factors studied. Finally, we applied these cationic starch-acrymide inarch- copolymerization as flocculant on treating activated sludge . pH value of the starch grafted cationic flocculant has little effect on flocculation.Qualitative analysis of its structure.Wave number of 1668 cm-1absorption peak was amide-based copolymers of the characteristic absorption peak .Wave number of 1546ccm-1 in the vicinity of the strong absorption peak that is Mr amide-CO-NH- deformation vibration absorption peak.Analysis confirmed :starch graft copolymer of acrylamide modified by cation existence of molecules-CO-NH-CH2-N(CH3)2.From electron micrographs can be seen the surface of starch graft copolymer and cation of the starch graft copolymer is an uneven, multi-hairy and curly loose shape was closely embedded in the overall state of the granular structure.Starch, we can see a combination of a large number of branched-chain acrylamide On the adsorption capacity of suspended solids, have greatly enhanced .Through the single factor experiment, factors that had influenced on the grafting yield were mainly considered, including absorbed does , reaction temperature, the mass ratio about acrylamide and starch .On the basis of the experiments, the three factors and three levels orthogonal experiment was used to search the optimum grafting yield parameters, the optimum conditions were:absorbed dose was 10kGy, reaction temperature was 30℃, m(acrylamide):m(starch)=2:1.Cation using irradiation method of response.Through the single factor experiment, factors that had influenced on the cationic degree were mainly considered, including Etherification agent , NaOH , water.On the basis of the experiments, the three factors and three levels orthogonal experiment was used to search the optimum cationic degree parameters, account of the cost factors the optimum conditions were: the dosage of etherification agent was 30g , the dosage of NaOH was 0.3g, the amount of water was 30ml.Compare the effect of flocculant used in the experiment. on flocculation.pH value of the starch grafted cationic flocculant has little effect on flocculation. However, have larger impact of polyacrylamide-type flocculants . Chloride-type flocculant charge more for good performance when the flocculation amount is larger. Flocculant Starch Graft dosage for the best for 450mg/L,Polyacrylamide and chloride is the best dosage 600mg/L.更多还原