大米淀粉膜的制备及其性能

大米淀粉颗粒粒径较小且均匀,在水中有较好的分散性,具有良好的成膜性并且可以在自然中降解,在食品包装、医用敷料及化妆品行业中有着广泛的应用。以大米淀粉为原料,NaOH为糊化剂,甘油为增塑剂,柠檬酸为交联剂和pH调节剂,采用流延法制备了淀粉膜。通过对淀粉颗粒的形貌观察及糊化温度、淀粉溶液的表观粘度及pH值测定、淀粉膜的力学性能、透光率及承载甘草酸二钾释放性能等的测定,研究了大米淀粉的糊化条件,柠檬酸、淀粉和甘油质量分数对淀粉膜性质的影响以及承载物质的释放情况。结果表明,大米淀粉呈光滑的多边形颗粒,直径为5~8 μm,在偏光显微镜下呈现马耳他十字结构,糊化温度范围为82.5~100.8 ℃。柠檬酸在淀粉成膜过程中会与淀粉分子相互作用,同时能够调节溶液的pH值以适应人体皮肤。淀粉质量分数越高,淀粉膜断裂伸长率越低,拉伸强度越高;甘油质量分数越高,淀粉膜断裂伸长率越高,拉伸强度越低。在甘油质量分数为3.0%时淀粉膜透光率最佳,结晶度最低。制备的淀粉膜能够承载且能高效释放抗炎物质甘草酸二钾,在护肤领域具有广泛的应用前景。     

以淀粉溶液为催化剂一锅三组分法合成四氢苯并[b]吡喃和3,4-二氢吡喃并[c]苯并吡喃衍生物(英文)

Tetrahydrobenzo[b]pyran and 3,4-dihydropyrano[c]chromene derivatives were synthesized via a one-pot three-component condensation of aromatic aldehydes with malononitrile and dimedone or 4-hydroxycoumarin in excellent yields in the presence of starch solution as a highly efficient homogenous catalyst.The use of a nontoxic and biodegradable catalyst,simple work-up procedure,and short reaction time are advantages of this method.     

Increasing the sensitivity of the spectrophotometric determinations of the oxygen content in YBCO superconducting samples using the I3-starch compound

The conditions for formation of the I₃⁻-starch compound and measuring its absorbance have been found, and a spectrophotometric method has been developed for the determination of the oxygen content in YBa₂Cu₃O_y superconducting bulk samples. The method involves the following stages: a decomposition of the sample in an acid medium in the presence of iodide ions under inert atmosphere; formation of a complex between Cu(II) and glycine; binding the I₃⁻-complex with a starch and the absorbance measurement of the colored I₃⁻-starch compound. The coefficient of the active oxygen is calculated by the ratio of the absorbances of two solutions and the method does not require both calibration and precise measuring sample mass. The accuracy of the results is confirmed applying the comparative spectrophotometric method that uses the yellow I₃⁻-complex. The precision of the results evaluated by the relative standard deviation is 2%. The developed method is sensitive and allows a sample mass about 2 mg to be used. The analysis is rapid and requires a simple and inexpensive apparatus. Thus the new method would be useful for an express analytical control of the oxygen content of YBCO-superconducting materials produced for the electronics.     

Superabsorbent nanocomposite and its properties

Starch-g-poly (AM-AMPS)/illite superabsorbent nanocomposite was synthesized by grafting copolymerization reaction of starch, acrylamide(AM) and 2-acrylamido-2- methyl propane sulfonic acid (APMS) in the presence of illite micropowder in deionized aqueous solution. The influence factors on water absorbency of the superabsorbent nanocoposite was optimized by single factor experiment. The synthesized superabsorbent nanocomposite exhibited the maximum water absorbency of 1320?g H₂O/g in deionized water and 142?g H₂O/g in 0.9?wt% sodium chloride (NaCl) solution. FTIR spectra confirmed that the grafting copolymerization between -OH groups on starch and monomers generated during the reaction. XRD analysis confirmed that crystal interlayer of illite was pulled open to 3.61?nm. TEM showed that illite slice layer randomly dispersed in the matrix of superabsorbent nanocomposite. The superabsorbent nanocomposite had a better thermal stability the corresponding superabsorbent material without illite by TGA and DSC analysis. The superabsorbent nanocomposite with excellent water absorbency and water retention could be especially useful in industry, agricultural, horticultural applications.     

应用单宁与淀粉为交联剂改性聚氨酯

通过植物原料单宁与淀粉对聚氨酯的改性可提高聚氨酯的机械性能和热性能 ,单宁成分的导入还能有效提高聚氨酯交联点密度、组分相容性和体系的形态结构均匀性 .当单宁的含量占投入的植物原料的6 0wt%时 ,单宁和淀粉聚氨酯网络互相贯穿表现出良好的相容性 ,其拉伸强度、杨氏模量分别提高到 5 1 9MPa和 30 8 4MPa ,积分程序分解温度达到 375℃ .同时单宁成分有望在一定范围内调节聚氨酯的降解速度 .     

Ce~（4＋）－Ce~（3＋）循环体系引发淀粉与丙烯酰胺接枝共聚合反应动力学研究

Ｃｅ~（４＋）－Ｃｅ~（３＋）循环体系引发淀粉与丙烯酰胺接枝共聚合反应动力学研究张连生，王玉芹，杨巍（黑龙江大学化学系，哈尔滨，１５００８０）（黑龙江商学院商管系，哈尔滨，１５００７６）关键词Ｃｅ~（４＋）－Ｃｅ~（３＋）循环引发、Ｃｅ~（４＋）复合引发?..     

A blood substitute from hydroxyethyl starch and hemoglobin

One method to increase the retention time of hemoglobin (Hgb) is to react it with a hydroxyethyl starch (HES) molecule. To examine this hypothesis, polymer-bound hemoglobin compounds were synthesized by the dialdehyde route. The electrophoretic mobility patterns indicate complete binding of the Hgb. Preliminary exchange-transfusion experiments in rates showed that they could survive for at least 10 h at Hct<10% when transfused with 6% HES-Hgb solutions. The retention time of the Hgb in the urine was increased to 12 h with these new polymers.     

Determination of carbohydrates in juices by capillary electrophoresis, high-performance liquid chromatography, and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry

The objective of this work was to develop a sample preparation procedure for determination of the carbohydrate profiles in commercial juice samples by three principally different analytical methods: capillary electrophoresis (CE) with indirect detection, high-performance liquid chromatography (HPLC), and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). The preparation and purification of juice samples prior to analysis is described. The method using Carrez reagents was found to be an efficient preparation tool for all three methods. The addition of Carrez reagents to the samples for mass analysis improved the quality of the mass spectra of oligosaccharides. The amounts of glucose, fructose, and sucrose as major carbohydrates in fruit juices measured by CE using a simple instrument are in good agreement with the HPLC values and the data declared by the producers of the juices. The results from both methods are critically evaluated and their impact for studies of authenticity is discussed. The decrease of sucrose amount during the storage of samples was explained by acid hydrolysis of this disaccharide.     

Reducing water absorption in compostable starch-based plastics

To improve the mechanical and physical properties of corn starch-based bioplastics the addition of natural polymers was investigated. Thermoplastic starch (TPS) was made of 70 g corn starch and 30 g glycerol. To this mixture 10–10 g of cellulose, hemicellulose and zein (protein) were added. Mechanical strength, water absorption and enzymatic degradation of composite materials were measured. Unfilled TPS and 10 w/w% polycaprolactone filled TPS were used as controls in the experiments. All the samples were biodegradable by enzymes. The tensile strength of unfilled and biopolymer filled TPS samples were significantly higher than that of the polycaprolactone filled one. Hemicellulose and zein composites had the best mechanical strength (10.4 and 11.5 MPa). Water uptake of each sample was measured using five different relative humidities. There were slight differences in water uptake of polycaprolactone, hemicellulose and zein filled TPS, however unfilled and cellulose filled samples absorbed more moisture than the polycaprolactone control in all the relative humidities used.     

In vitro degradation and swelling behaviour of rubbery thermoplastic starch in simulated body and simulated saliva fluid and effects of the degradation products on cells

Degradation in vitro is of importance in implanted biological industry. This research investigated the swelling and degradation behaviours of glycerol plasticized thermoplastic starch (GTPS) in simulated body fluid (SBF) and simulated saliva fluid (SSF), respectively. The weight loss, swelling degree and linear extensibility as a function of time were measured. Changes in the morphology (SEM), chemical structure (FT-IR), crystal property (XRD) and thermogravimetic property (TG) during degradation were also investigated. Results show that the degradation in SSF was much quicker than that in SBF. About 1 h was needed for the swelling equilibrium in SBF, which was a little quicker than that in SSF. In alkaline solution the swelling speed and the swelling degree were larger than those in neutral and acidic solutions. The degradation in SBF was typical bulk degradation. In SSF the surface and bulk degradation took place synchronously, but the surface degradation played an important role in the first 2 h. Results from FT-IR and XRD suggest that the glycosidic linkages in starch chains were broken and the crystal structure in GTPS was destructed during degradation. Cytotoxicity test was used to investigate the effects of the short-term extracted dilutions and long-term degradation products on the cells, which illustrates that the degradation products not only had non-toxicity but also accelerated the cells' growth.