魔芋葡甘聚糖溶胶流变特性及应用研究进展

主要综述了魔芋葡甘聚糖和改性魔芋葡甘聚糖溶胶流变特性．以及各种改性方法对其溶胶流变特性的影响．魔芋葡甘聚糖流变特性的多样性．未改性的魔葡甘聚糖是极为典型的假塑性流体．而改性后的魔芋葡甘聚糖开始呈现出较为明显的牛顿流体行为,且其流变特性受诸多因素的影响．葡甘聚糖经改性后．其透明度、粘度、冻融稳定性均明显改善。此外还总结了魔芋葡甘聚糖溶胶的应用。     

魔芋胶的交联化学改性研究

采用三氯氧磷、氯乙酸醚化和卡拉胶复配三种方法对魔芋葡甘聚糖(KGM)进行改性,采用AR500动态流变仪测定了魔芋胶的剪切弹性模量和粘性模量随温度和角频率的变化,并与改性后的样品作了比较。结果显示,不同的改性方法可以有效调控魔芋胶的流变性,使之适应更广泛的技术要求,拓展应用范围。     

魔芋葡甘聚糖材料疏水改性的研究进展

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。     

环境友好型胶粘剂的研制

为了减少对环境的污染,研制了环境友好型胶粘剂。以魔芋胶(KGM)、双氧水(H2O2)为主要原料,通过加入交联剂和填料等制备了环保型魔芋胶胶粘剂。实验结果表明,氧化改性魔芋胶胶粘剂性能与常用胶粘剂相当,且具有环保的优点;与改性淀粉胶粘剂相比则性能更佳。     

改性魔芋葡甘聚糖与苯丙乳液共混体系流性能研究

研究了改性魔芋葡甘聚糖与苯丙乳液共混体系的流变性能，结果表明，改性魔芋葡甘聚糖对苯丙乳液有极好的混溶性，增稠性及流平性。     

乙酸酐对魔芋葡甘聚糖的改性

研究了乙酸酐对魔芋葡甘聚糖的改性,制备了魔芋葡甘聚糖醋酸酯,优化了制备工艺条件,得出了酸性催化剂条件下,乙酰化魔芋葡甘聚糖的最佳改性工艺条件为:n(乙酸酐)∶n(魔芋葡甘聚糖)=4 8∶1,反应温度50℃,反应时间4h,催化剂c(H2SO4)=0 038mol/L,取代度DS=0 662。物化性能测试表明,取代度超过0 270时,魔芋葡甘聚糖醋酸酯在水中溶解;60℃时最大溶解度为w(魔芋葡甘聚糖醋酸酯)=12%,取代度超过0 469时,魔芋葡甘聚糖醋酸酯能制成均匀的薄膜,膜厚10～30μm。     

凹凸棒石/魔芋葡甘聚糖纳米复合材料的制备及性能

以江苏盱眙提纯凹凸棒石为原料,魔芋葡甘聚糖(KGM)为基体,采用共混法制备了凹凸棒石/魔芋葡甘聚糖纳米复合材料.利用傅立叶红外光谱(FTIR)和热重分析(TG)手段对材料进行了表征.力学性能测试结果表明,改性凹凸棒石适量的引入,能提高复合材料的力学性能.纳米复合材料制备的较佳条件为:季铵盐用量为凹凸棒石用量的12％,改性时间为120 min,改性温度为85℃,改性凹凸棒石的填充量为魔芋质量的0.04％,增塑剂甘油的用量为魔芋质量的0.09％.FTIR表明:增塑剂甘油的加入,并未影响复合材料的结构.复合材料的热稳定性高于KGM薄膜.     

魔芋葡甘聚糖及其凝胶的研究进展

从结构、改性等方面综述了魔芋葡甘聚糖及其凝胶的研究与应用     

改性魔芋葡甘聚糖与苯丙乳液共混体系统变性能研究

研究了改性魔芋葡甘聚糖与苯丙乳液共混体系的流变性。     

魔芋葡甘露聚糖的化学改性研究

综述了魔芋葡甘露聚糖的化学结构和近年来化学改性的研究。     

不同分子量磺酰化魔芋葡甘聚糖的制备与生物活性研究

利用纤维素酶降解原始魔芋葡甘聚糖,制得魔芋葡甘低聚糖,以N,N-二甲基甲酰胺为溶胀剂,用吡啶-氯磺酸法制备了一系列分子量不同而取代度相近的磺酰化魔芋葡甘聚糖(KGMS).通过对KGMS分子量的测试,探讨了磺酰化条件对磺酰化衍生物的影响;以红外光谱、元素分析等表征其结构,并通过生物活性测试(包括体外抗凝血时间、体外抗肿瘤活性、抑菌活性等),探讨了不同分子量的磺酰化魔芋葡甘聚糖的生物活性.     

Blend films from chitosan and konjac glucomannan solutions

Blend films were prepared by blending 7 wt % konjac glucomannan (KGM) aqueous solution with 2 wt % chitosan (CH) in acetate solution and dried at 40°C for 4 h to obtain the transparent films. Their structure and properties were studied by infrared (IR), wide‐angle X‐ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Crystallinities of the blend films decreased with the increase of konjac glucomannan. The thermostability, tensile strength, and breaking elongation of the blend films in dry state were obviously higher than those of both konjac glucomannan and chitosan films. Tensile strength of the dry blend film achieved 73.0MPa when the weight ratio of chitosan to konjac glucomannan was 7:3. The structure analysis indicated that there is a strong interaction between konjac glucomannan and chitosan resulted from intermolecular hydrogen bonds. The water solubility of the blend films was improved by blending with konjac glucomannan, so they have promising applications to soluble antiseptic coating of pills. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 509–515, 2000     

Some viscous behaviors of styrene-acrylic emulsion thickened with konjac glucomannan

Due to the importance of viscous behavior of fluidic material in the production, storage and application, some viscous behaviors of styrene-acrylic emulsion thickened with konjac glucomannan were investigated through steady and dynamic measurements with numerical model fits. Results demonstrated that the viscosities at various konjac glucomannan colloids consistently decreased with the shear rate/angular frequency rising from 0.1 to 100 s⁻¹, behaving shear thinning phenomenon which could be fitted to the Sisko model. Temperature ramp data from 7 to 60 °C showed a temperature-induced thickening, which was slightly enhanced by konjac glucomannan. The tests for stability to time, pH value and NaCl, CaCl₂ did not show considerable effect of the konjac glucomannan.     

In situ pH-decrease-induced gelation of sodium alginate/carboxymethylated konjac glucomannan

The gelation kinetics and rheological properties of a mixture system containing two anionic polysaccharides, sodium alginate and carboxymethylated konjac glucomannan, in the presence of glucono-delta-lactone were investigated with dynamic viscoelastic measurements. The slow release of protons induced by glucono-delta-lactone gave birth to partly uncharged polymer chains and partly shielded electrostatic repulsion, resulting in an interpolymer association. This segregative interaction brought about a significant improvement in the elastic modulus of the resultant gel. The strongest synergism occurred at a carboxymethylated konjac glucomannan concentration of 29.9 wt %, exhibiting the highest gel strength. Increasing the content or the degree of substitution of carboxymethylated konjac glucomannan resulted in slower gelation kinetics. The fractal dimension of the incipient gel, which was not greatly affected by the mixing ratio or the degree of substitution of carboxymethylated konjac glucomannan, reflected a rather compact gel structure network. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Blend films from konjac glucomannan and sodium alginate solutions and their preservative effect

In order to enhance the mechanical properties of konjac glucomannan film in the dry state and research the application of konjac glucomannan on food preservation domain, blend transparent film was prepared by blending 3 wt % sodium alginate aqueous solution with 4.5 wt % konjac glucomannan aqueous solution and dried at 40^oC for 4 h. The structure and properties of the blend films were studied by infrared, wide angle X‐ray diffraction, scanning electron microscopy, and differential thermal analysis. Crystallinities of blend films were increased with the increase of sodium alginate. The tensile strength and breaking elongation of the blend films in dry state were obviously higher than those of both sodium alginate and konjac glucomannan films. Tensile strength of the dry blend film achieved 77.8 MP_a when the retention of sodium alginate in the film was 27.9 wt %. The structure analysis indicated that there was a strong interaction between konjac glucomannan and sodium alginate, and this is resulted from the intermolecular hydrogen bonds. Moisture content and degree of water swelling of the blend films were increased due to the introduction of sodium alginate. Results from the film coating preservation experiment to litchi and honey peach showed that this blend film had water‐holding ability. The fruit weight loss rate and rot rate both decreased by various values. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 617–626, 2000     

Improvement of physical properties of crosslinked alginate and carboxymethyl konjac glucomannan blend films

Blend films from carboxymethyl konjac glucomannan and sodium alginate in different ratios were prepared by blending 4 wt % sodium alginate aqueous solution with 2 wt % konjac glucomannan aqueous solution. After crosslinking with 5 wt % calcium chloride aqueous solution, the blend films formed a structure of semi‐interpenetrating networks. The structure and physical properties of both uncrosslinked and crosslinked films were characterized by Fourier transformed infrared spectra (FTIR), differential thermal analysis (DTA), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile tests. The results indicated that the mechanical properties and the thermal stability of the films were improved by blending sodium alginate with carboxymethyl konjac glucomannan due to the intermolecular hydrogen bonds between sodium alginate and carboxymethyl konjac glucomannan. The crosslinked blend films with Ca²⁺, compared with uncrosslinked blend films, exhibited further improved physical properties due to the formation of a semi‐IPN structure. Furthermore, the degree of swelling of the crosslinked films was also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2554–2560, 2002     

羧甲基魔芋葡甘聚糖的制备及应用

以异丙醇为分散剂,在碱性介质中一氯乙酸(MCA)和魔芋葡甘聚糖(KGM)反应制备了系列羧甲基魔芋葡甘聚糖(CMKGM)。研究了反应时间、反应温度、MCA和NaOH用量等因素对取代度及反应率的影响,优化反应条件为:n(KGM)∶n(MCA)∶n(NaOH)=1∶1∶2,反应温度为50℃,反应时间为4 h,反应率可达90%;将制得的CMKGM用环氧氯丙烷交联,并将其用于吸附水溶液中的Pb2+。结果表明,交联羧甲基魔芋葡甘聚糖能有效吸附水中的Pb2+,当取代度(DS)为0.568,Pb2+起始质量浓度为300 mg/L时,吸附容量为29.19 mg/g,去除率仍高达97.3%。     

海藻酸-羧甲基葡甘聚糖共混膜的结构与性能研究

对魔芋葡甘聚糖进行羧甲基化改性,制得醚化度为0.54的羧甲基葡甘聚糖。再利用溶液共混法制备海藻酸钠-羧甲基葡甘聚糖共混膜,通过红外光谱、X-射线衍射、原子吸收光谱和扫描电镜对共混膜的结构进行了表征;并测定了不同配比共混膜的拉伸强度、断裂伸长率,吸水率和水蒸汽透过率,同时考察了NaCl浓度对共混膜吸水率的影响。结果表明:共混膜中海藻酸和羧甲基葡甘聚糖间具有较强的相互作用,良好的相容性。共混膜具有良好的力学性能,在生物材料领域有潜在利用价值。