共查询到17条相似文献,搜索用时 109 毫秒
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以可溶性淀粉为原料,K2S2O8-Na2SO3为引发剂,用反相悬浮法合成了N,N'-亚甲基双丙烯酰胺交联淀粉微球CSM.研究了交联剂质量分数、反应温度和引发剂浓度对微球产率、溶胀度、平均粒径的影响规律.用扫描电镜观测了样品形貌,用FT-IR对其结构进行了表征,用XRD、DSC以及TGA对其物理性质进行了分析.结果表明,所合成的交联淀粉微球形态圆整,表面光滑,粒度均匀,微球中存在酰氨基结构.与可溶性淀粉相比,淀粉微球结晶度降低,热稳定性增加. 相似文献
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交联羧甲基玉米淀粉/PVA复合膜制备工艺的研究 总被引:5,自引:2,他引:3
以玉米淀粉为原料,采用先醚化后交联改性工艺合成了交联羧甲基玉米淀粉(CCMS).通过改性淀粉与聚乙烯醇(PVA)溶液共混反应,并辅以增塑剂、增强荆、交联剂及疏水化改性剂等加工助荆制备了性能优异的CCMS/PvA复合膜.研究了复合膜制备过程中的影响因素及其对薄膜耐水性能、透光性能和力学性能的影响.结果表明,当交联羧甲基玉米淀粉与PVA的质量比为7:3,甘油用量为10%(质量分数),复合交联剂用量3.3%(质量分数),疏水化改性荆聚酰胺多胺环氧氯丙烷树脂(PPE)用量为1.5%(质量分数),溶液pH为10,反应温度88℃,反应时间35min时,淀粉膜的拉伸强度为40.5MPa,断裂伸长率为311%,透光率为82%,吸水率最小为3.6%(质量分数). 相似文献
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轻度交联羧甲基化复合变性淀粉的研究 总被引:6,自引:1,他引:5
张 《高分子材料科学与工程》2000,16(6):154-156
针对羧甲基淀粉存在的粘度稳定性和耐热稳定性较差的问题,在CMS中引入少量交联剂合成了部分交联羧甲基化复合变性淀粉,研究表明,选用环氧氯丙烷作为交联剂,在用量不超过0.1%时可得到性能优良的交联羧甲基淀粉,其粘度、粘度稳定性和耐热稳定性都有明显提高并达到了相关的标准,可用于相应行业替代CMC使用。 相似文献
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以双醛淀粉为交联剂,采用溶液交联的方法对明胶进行交联改性.研究了反应条件对交联明胶吸水性能的影响.结果表明,交联明胶吸水能力随双醛淀粉/明胶增加而先增加后降低,随反应温度增加而减小,随反应混合物pH值增加而增加.当pH=2,温度为90℃,双醛淀粉/明胶=0.3,明胶溶液浓度为20%时,明胶的吸水倍率可降低至1.62.FTIR显示双醛淀粉对明胶的交联作用主要是形成希夫碱结构. 相似文献
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本文对羧甲基羟丙基纤维素(CMHPC)及其与三价铬和铝离子的交联产物进行拉曼谱图分析,了解关于交联对CMHPC结构所产生的影响。结合红外谱图和动态粘弹性分析,进一步明确了CMHPC交联产物的结构特征。 相似文献
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Zhao XB Fraser JE Alexander C Lockett C White BJ 《Journal of materials science. Materials in medicine》2002,13(1):11-16
Hyaluronan has great potential in medicine as a biomaterial. However, in its native form, hyaluronan is rapidly metabolized in vivo by free radicals and enzymes such as hyaluronidase, and it is highly soluble. Various methods have been adopted therefore, to modify the physicochemical properties of hyaluronan, while maintaining biocompatibility, and thereby widen its spectrum of therapeutic applications.Hyaluronan has four reactive groups (acetamido, carboxyl, hydroxyl and the reducing end) available for crosslinking to itself or other polymers. Using a variety of crosslinking agents, researchers have developed a host of crosslinked hyaluronan derivatives with an increased in vivo residence time. This chemical modification has enabled the production of gels and films, which can be used in applications such as the prevention of post-surgical adhesions, wound healing and dermal augmentation.We have found that if hyaluronan is crosslinked to itself, or to other polymers (either synthetic or biopolymer), in two stages, then a high degree of crosslinking is achieved, conferring improved biostability. In each of the two stages, the same crosslinking agent is used, but different functional groups are bound by altering the reaction conditions. The novel process can be tailored to yield water insoluble gels and films with a broad range of physical and chemical characteristics, and greater resistance to degradation by hyaluronidase and free radicals. These derivatives are currently undergoing biocompatibility testing, and should ultimately lead to a series of innovative second-generation medical products. 相似文献
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Preparation and characterization of blends of recycled polystyrene with cassava starch 总被引:1,自引:0,他引:1
Tais A. P. F. Pimentel Jussara A. Durães Adriana L. Drummond Daniela Schlemmer Rosana Falcão Maria José Araújo Sales 《Journal of Materials Science》2007,42(17):7530-7536
Secondary recycling is an alternative to solve at least part of the worldwide pollution problem caused by persistence of petrochemical
plastic materials in the environment. In this work we report the secondary recycling of disposable polystyrene (PS) using
cassava starch (Manihot esculenta Crantz) and a natural plasticizer extracted from a palm tree of the Amazon: Buriti (Mauritia flexuosa L.) oil. 13C-NMR spectroscopy reveals incorporation of the oil in the polymer matrix. Although phase separation had occurred, SEM depicts
a very good dispersion of the thermoplastic starch (TPS) in the PS matrix with distinct domains. Thermal analyses indicate
smaller thermal stability of the PS/TPS blends compared to PS and that possess intermediate characteristics between the pure
PS and TPS, confirmed by DRX. Kinetic study shows a lowering of the activation energy for the thermal degradation of the blends. 相似文献
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以可溶性淀粉为原料,用反相悬浮法合成了N,N'-亚甲基双丙烯酰胺交联淀粉微球ASM.最佳合成条件是可溶性淀粉2g,N,N'-亚甲基双丙烯酰胺0.2g,K2S2P8 0.04g,W/O相体积比1∶3,反应时间2h,反应温度50℃.ASM外型规则,粒度10~20 μm.探讨了成球机理,提出了交联反应主要在淀粉分子结构外围进行的推论并获得了实验支持.在25℃,ASM对Cu2 、Cr3 、Cd2 、Pb2 的饱和吸附量分别是2.75、2.20、0.88、0.77 mmol·g.HCl、ZnCl2使ASM对Cu2 的吸附量明显降低,MgCl2使吸附量略有降低.ASM的空间网状结构使金属离子容易深入其内部形成多点配位,配位吸附是ASM吸附金属离子的主要作用形式. 相似文献
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采用共沉淀水热法合成了MgAlCe三元复合层状氢氧化物。详细探讨了x(Al)/x(Ce)、水热温度及pH值对合成产物物相的影响。通过XRD、TG/DTG、SEM及TEM对制备的水滑石进行分析。结果表明,当x(M2+)/x(M3+)=1.5,x(Al)/x(Ce)=16∶1,pH值=7.9条件下进行多种离子共沉淀,并经140℃、10h水热处理后,得出的产物结晶度较高,物相纯净,具有典型层状结构,并且其热稳定性较好,层间羟基硝酸根失去温度在300~500℃之间,表明其作为阻燃剂具有很大的潜力。 相似文献
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戊二醛交联淀粉微孔发泡材料(SMCF)的制备及表征 总被引:1,自引:0,他引:1
以玉米淀粉为原料,将糊化后的淀粉溶液与戊二醛交联,采用溶剂置换制得高白度、表面带有微孔结构、并具有一定抗水性能的淀粉微孔发泡材料(starch microcellular foam,SMCF).研究了交联反应及溶剂置换各因素对SMCF白度、湿含量及微孔形成的影响,确定最优工艺:交联剂戊二醛的用量为10g戊二醛/100g... 相似文献
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