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玉米麸皮中阿拉伯木聚糖的提取、结构及性质 总被引:1,自引:0,他引:1
采用碱-过氧化氢法从玉米麸皮中提取阿拉伯木聚糖(AX),并考察其基本性质。研究发现:0.5 mol/L Na OH溶液提取所得阿拉伯木聚糖色泽浅、产量较高且未发生降解;阿拉伯木聚糖主要由阿拉伯糖和木糖单元组成,还含有少量葡萄糖和半乳糖单元;阿拉伯木聚糖从215℃开始发生热分解,350℃时分解完全;阿拉伯木聚糖还具有一定的增稠效果;此外,AX可用来制备水包油型乳液,所制得的乳液十分稳定。 相似文献
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通过对水溶性玉米麸质阿拉伯木聚糖(CAX)进行改性,使CAX具有抗氧化性。将CAX溶解到DMA/Li Cl体系中,以三乙胺为缚酸剂,与对香豆酸酰氯进行酯化反应得到阿拉伯木聚糖对香豆酸酯(p-CA-CAX)。用红外、核磁对其结构进行了鉴定,表明对香豆酸(p-CA)以酯键的形式连接在CAX上。用高效液相色谱确定了p-CA的取代度,p-CA与CAX的糖苷键的摩尔比分别为1∶5,1∶4,1∶3,1∶2和1∶1时,取代度分别为0.38,0.51,0.63,0.83和0.94。用凝胶渗透色谱确定了不同取代度的p-CA-CAX的分子量,p-CA-CAX-0.38,p-CA-CAX-0.51和p-CA-CAX-0.63的分子量分别为3.52×10~5,3.85×10~5和3.93×10~5。脂质过氧化物的检测和抗氧化能力指数(ORAC)的测定表明,p-CA-CAX具有较好的抗氧化性,而且p-CA含量越高,p-CA-CAX的抗氧化性越好。 相似文献
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从玉米麸皮中提取碱溶性阿拉伯木聚糖(AX)并用乙醇分级。用体积排除色谱-多角度激光光散射联用(SEC-MALS)和动态光散射(DLS)研究了AX的构象和聚集。碱溶性麸质AX的相对分子质量随均方旋转半径(Rg)的变化可以用Mw~Rdfg表示。玉米麸质AX分子链的分形维数(df)为1.47,其结构因子ρ=Rg/Rh为1.70。忽略分子间作用,根据"蠕虫链"模型可以估算出玉米麸质AX的持久长度(Lp)为1.72 nm。即使在很稀的溶液中,玉米麸质AX也可以形成紧密的聚集,其df在3.0左右。 相似文献
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魔芋葡甘聚糖材料疏水改性的研究进展 总被引:6,自引:3,他引:3
介绍了魔芋葡甘聚糖与高分子材料共混疏水改性的方法,评述了化学改性中魔芋葡甘聚糖脱乙酰基化、交联、接枝共聚、互穿聚合物网络、羧甲基化等疏水改性的最新研究进展,探讨了其今后的研究方向,并提出了开发热塑性KGM材料这一前沿性课题。 相似文献
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A new pathway to construct high-strength, ultrastretchable hydrogels based on tailored modified carboxymethyl cellulose (TMCMC)and hydrophobic association(HPA) system was investigated. TMCMC was prepared from degradation of carboxymethyl cellulose (CMC)/N,N′-methylene bisacrylamide (MBA) chemical cross-linked hydrogels. The residual double bonds of TMCMC, confirmed by 1H-NMR and FTIR analysis, reacted with acrylamide in HPA to form TMCMC/HPA hydrogels, and the homogeneous and fine spatial network structure of TMCMC/HPA hydrogel could be observed by scanning electron microscopy. Rheological analysis revealed that the coexistence of physical and chemical crosslinking in TMCMC/HPA hydrogels. Further studies showed that TMCMC/HPA hydrogel with MBA content of 0.5 wt% has outstanding mechanical properties, and its fracture stress, elongation and tensile strength reach 1.17 MPa, 3717.05% and 15.68 MJ·m−3, respectively. Moreover, the hydrogel displayed good swelling resistance and stable strain electrical signal response. 相似文献
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Isolated corn hull arabinoxylan was dissolved in water and provided a clear solution. Plasticizer (glycerol, propylene glycol, or sorbitol) was added to the arabinoxylan solution at 0–20 wt % (film dry weight), which was cast into stable films. Film thickness ranged from 22 to 32 μm. Mechanical properties, moisture content, and water vapor permeability (WVP) were studied for the arabinoxylan‐based films as a function of plasticizer concentration. Measured data for the corn hull arabinoxylan–based films were 13–18 wt % moisture content, 10–61 MPa tensile strength, 365–1320 MPa modulus, 6–12% elongation, and 0.23–0.43 × 10?10 g m?1 Pa?1 s?1 water vapor permeability. Plasticized arabinoxylan films produced in this study had lower WVPs than those of unplasticized films, which is likely attributable to the phenomenon known as antiplasticization. Scanning electron micrographs showed a homogeneous structure on film surfaces. Films containing sorbitol had the best moisture barrier properties. When grapes were coated with arabinoxylan and arabinoxylan/sorbitol films, weight loss rates of the fruit decreased by 18 and 41%, respectively, after 7 days. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2896–2902, 2004 相似文献
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用γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)、1-氯辛烷对低相对分子质量聚乙烯亚胺(PEI)进行疏水接枝改性,得到了含硅疏水改性聚胺阻垢剂。通过FTIR、TG、粒径分析、Zeta电位测试等分析改性后聚胺阻垢剂的结构与性能。结果表明,改性后产物热稳定性提高、黏度增大、表面张力降低、溶液粒径增大。将改性聚胺阻垢剂用于分散铝硅酸钠颗粒,对处理前后的颗粒进行红外光谱表征,并通过对悬浮分散液进行稳定性、颗粒沉降等测试,评价聚胺阻垢剂的阻垢分散性能并初步讨论其分散机理。当m(PEI, Mw=10000)∶m(KH560)∶m(1-氯辛烷)=10∶2∶0.5,反应时间6 h,反应温度75℃时,合成的阻垢剂分散性能最佳。当结疤的质量浓度为30 g/L时,悬浮液颗粒沉降速度达到最低值0.047 cm/d,沉降速率减小程度达到94.8%,分散性显著提高。经过改性后的PEI在氧化铝工业生产中具有高效的阻垢作用,可通过在工厂进行条件优化,进一步替代传统的强酸型阻垢剂,减小管道腐蚀程度,降低能耗。 相似文献
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新型疏水二氧化硅的制备 总被引:12,自引:1,他引:12
采用表面改性剂VTES处理SiO2粒子,使之具有良好的疏水性,并且反应副产物没有腐蚀性,有利于保护设备和环境保护,并对其制备工艺条件进行了研究。 相似文献