淀粉和生物降解大分子间的半互穿聚合物网络的耐水性研究

以淀粉和可生物降解的PCL或PHBV等疏水性脂肪族聚酯为原料, 制备了淀粉基的Semi-IPN材料. 加入PCL或PHBV等疏水性大分子的使淀粉基Semi-IPN材料的耐水性能相对于原淀粉有很大的改善, 通过热处理和溶剂化作用能使Semi-IPN的耐水性进一步提高.     

淀粉类生物降解泡沫塑料的研究进展

淀粉类生物降解泡沫塑料是一种重要的环境友好材料,具有极其良好的发展前景。本文综述了近年来淀粉类生物降解泡沫塑料性能的研究进展。     

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.     

Hydrophobic modification of starch via grafting with an oxazoline-derivative

The application of starch in tailored materials is limited because of the high hydrophilicity of the polysaccharide. Thus, simple and efficient paths for the hydrophobic modification of native, cationic or thermoplastic starches by means of a radical grafting process using bifunctional fatty acid oxazoline derivatives were investigated. The modified starches can be manufactured by means of an extrusion process showing high grafting yields at adjustable grafting contents from 2.5 to 30%. Resulting starch materials are distinguished by modified water absorption properties and solubility, which is a prerequisite for their application in the paper or painting industry. Moreover the structure of the oxazoline derivative supplies the opportunity for reactive blending of different polymers carrying carboxyl, amino, mercapto or epoxy groups. This is exemplarily shown for the conversion with biodegradable polyesters, which contain carboxylic acid functions. Film forming properties of the new starch-based materials were studied. Results of the examination of manufactured shouldered test bars of starches coupled with biodegradable polyesters are presented as well.     

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?..     

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.     

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.     

STUDIES ON GRAFT COPOLYMERIZATION OF DL-LACTIDE ON CORN STARCH AND BIODEGRADABILITY OF THE COPOLYMERS

1.INTRODUCTIONItiswellknownthataliphaticpolyestershaveahighlevelofbiodegradabilityandstarchwasakindoftotallybiodegradablenaturalpolymermaterial[1,2].Thebiodegradabilityofthealiphaticpolyesters/starchgraftcopolymerswereinvestigatedextensively[3-6].Thepresentpaperrelatestoaprocedureforpreparingastarch/D,L-lactidegraftcopolymer,akindofhydrophobic,totallybiodegradableproducthavinggoodwater-resistanceandmechanicalproperties.ThegraftcopolymersweresynthesizedbyreactingD,L-lactidewithcornstarchi…