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%。     

阳离子魔芋葡甘聚糖的制备与表征

以3-氯-2-羟丙基三甲基氯化铵(HAT)为阳离子醚化剂,天然魔芋精粉为原料,异丙醇为分散剂制得系列季铵盐阳离子魔芋葡甘聚糖(CKGM)。研究了HAT、催化剂NaOH、反应温度和反应时间对阳离子取代度(DS)的影响,用元素分析仪测定了CKGM的取代度。确定较佳反应条件为:反应温度50℃,反应时间2 h,n(HAT)∶n(魔芋葡甘聚糖)∶n(NaOH)=1.5∶1∶2,DS为0.361,反应率为24.1%,并用FTIR1、HNMR和13CNMR进行了表征。     

魔芋葡甘聚糖在离子液体中的均相乙酰化研究

魔芋葡甘聚糖在新型离子液体1-烯丙基-3-甲基咪唑盐酸盐(AMIMCL)中,在无催化剂的条件下,通过乙酸酐成功均相合成了乙酰化魔芋葡甘聚糖。探讨了反应时间、反应温度和乙酸酐与魔芋葡甘聚糖中羟基的摩尔比对取代度的影响。在反应时间为0.75h、反应温度为80℃、乙酸酐与魔芋葡甘聚糖中羟基的摩尔比为6∶1时,取代度可达到最大值2.15。采用FTIR、1HNMR和13CNMR对乙酰化产物的结构进行分析表征,结果表明,乙酰化反应成功进行。同时对不同取代度的产物在不同溶剂中的溶解能力进行了测试。     

羧甲基魔芋葡甘聚糖的制备及其对铅的吸附研究

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)=112,反应温度为50℃,反应时间为4 h.将制得的CMKGM用环氧氯丙烷交联,结果表明交联羧甲基魔芋葡甘聚糖(CCMKGM)能有效的吸附水中的Pb2+;且再生后的CCMKGM吸附性能好,解吸附百分率高.     

魔芋葡甘聚糖的H2O2氧化改性及其流变性能研究

用过氧化氢(H2O2)对魔芋葡甘聚糖进行氧化改性,探讨了不同料液比、pH值、温度、H2O2加入量及反应时间对氧化反应的影响,得到最佳的反应条件为料液比为1∶4、pH为7.5、反应温度为45℃、H2O2加入量为2.4%、反应时间为4 h;改性魔芋葡甘聚糖水溶胶非牛顿行为显著降低,溶胶粘度稳定性及酸碱稳定性大幅提高.     

交联羧甲基魔芋葡甘聚糖的合成及阻垢性能研究

将天然产物魔芋粉进行改性,制备了交联羧甲基魔芋葡甘聚糖,通过静态阻垢法对交联羧甲基魔芋葡甘聚糖的阻碳酸钙垢性能进行了评价.结果表明,当温度为70℃、pH≤7.(p)(Ca2+)≤500 mg/L时,交联羧甲基魔芋葡甘聚糖具有良好的阻垢效果.推测其阻垢作用机理主要是晶格畸变作用和螯合增溶作用.     

交联魔芋葡甘聚糖水凝胶包裹尿素的缓释效果

以魔芋粉为原料，经三级醇溶去杂工艺，得纯化魔芋葡甘聚糖；以环氧氯丙烷为交联剂，制备出交联魔芋葡甘聚糖水凝胶；交联魔芋葡甘聚糖水凝胶于尿素水溶液中强力搅拌，抽滤，制得包裹尿素的交联魔芋葡甘聚糖水凝胶。试验了交联魔芋葡甘聚糖水凝胶对尿素的包裹率；以及包裹尿素的交联魔芋葡甘聚糖水凝胶缓释尿素的效果。结果表明，交联魔芋葡甘聚糖水凝胶对尿素缓释效果良好。     

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.     

羧甲基葡甘聚糖的制备

葡甘聚糖经羧甲基化改性后,其溶解性、抗潮性、成膜性能等明显改善,可用作空心胶囊的囊材。通过正交试验,得出了葡甘聚糖羧甲基化改性作囊材的最佳反应条件：6g魔芋精粉,6g氯乙酸,1．2g碘化钾,70℃水浴反应4h,所得产物的取代度为0.571。研究了改性后羧甲基葡甘聚糖的理化性能。     

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     

Preparation of konjac glucomannan ester of palmitic acid and its emulsification

Various degrees of palmitoylated konjac glucomannan (PKGM) are prepared by a heterogeneous method. Differential thermal analysis thermographs show PKGM having 0.51 degrees of substitution (DS) gave a new crystalline peak at higher temperature. With the increase of DS, the former crystalline state of konjac glucomannan will disappear; PKGM only shows the new crystalline state. Furthermore, the effect of the DS of PKGM on its emulsifying ability has been investigated in the water in oil and oil in water systems. It is demonstrated that it is a kind of good water in oil emulsifier, with the DS ranged between 1.00 and 1.70, whereas DS < 0.50. It is a kind of good oil in water emulsifier and an interesting phenomenon appears in the water in oil system. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1035–1038, 1998     

一种改性魔芋葡甘露聚糖的合成与表征

以三乙胺为催化剂,用没食子酸对魔芋葡甘露聚糖（KGM）进行酯化改性,反应条件为：m（KGM）∶m（三乙酰没食子酰氯）=1∶2,反应温度50℃,时间3 h,用饱和乙酸钠的无水乙醇溶液进行脱除乙酰基,得改性KGM,总收率为57.9%。     

魔芋葡甘聚糖的改性修饰及其应用

详述了魔芋葡甘聚糖的改性修饰技术．如化学改性、物理改性、生物改性等。评述了魔芋的深加工及作为生物降解性材料的应用。     

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     

Preparation and characterization of polylactide/thermoplastic konjac glucomannan blends

In this article, a new degradable thermoplastic konjac glucomannan (TKGM) was synthesized by graft copolymerization of vinyl acetate and methyl acrylate onto konjac glucomannan (KGM). Melt blending of polylactide (PLA) and TKGM has been performed in an effort to improve the processing and comprehensive mechanical properties of PLA and TKGM without compromising its degradability and biocompatibility. The miscibility, processing rheology, phase morphology, thermal properties, interaction, crystallization and mechanical properties of PLA/TKGM blends were investigated in detail. The thermal processing property of PLA/TKGM blend (60/40) was quite close to low density polyethylene (LDPE). As observed from the tan δ curves in dynamic mechanical analysis, all of the blends exhibit a single glass transition over the entire composition range, indicating that the blends were thermodynamically miscible. The TKGM exhibited a relatively broad endothermic peak at around 120 °C, which was lower than that of KGM. And an obvious glass-transition behavior was obtained around 26.6 °C. Furthermore, the PLA/TKGM blend (60/40) had a very high elongation at break of 234.8%, while the tensile strength remained as high as 36.5 MPa. And the PLA/TKGM blend (20/80) resulted in an even greater ductility with an elongation at break of 520.5% as compared with 14.1% for pure PLA. A substantial increase in the non-notched impact strength was also observed with the PLA/TKGM blend (20/80) demonstrating two times the impact strength of pure PLA.     

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