淀粉塑料发展趋势

降解塑料发展迅速 ,经历了一段开发过程后 ,人们终于认识到只有开发真正可降解的塑料才能对环境友好 ,造福人类。文中简述了目前国内外淀粉塑料发展现状 ,并对各种淀粉塑料的优缺点进行分析 ,指出了其发展前景将是十分广阔的     

淀粉基生物降解塑料研究进展

随着人们对塑料消费的日趋增加 ,废塑料对环境的污染也日益严重。生存环境的压力和可持续发展的要求 ,迫使人们寻求使用可被生物降解的制品替代石油化学塑料的可能性。在生物可降解材料中 ,淀粉基生物降解塑料以其可完全降解性和可再生性爱到人们的青睐。本文按加工技术水平将淀粉生物降解塑料分为四类型 ,阐述了各类型降解机理、产品特性和存在问题 ,提出今后研究的重点 ,旨在促进淀粉基生物降解塑料的研究与发展。     

淀粉基生物可降解材料的研究进展

淀粉基生物可降解材料是一种可再生、可降解的高分子共混物质,它具有来源广、成本低、性能良好的特点,是一种理想的塑料替代品。主要详细阐述了热塑性淀粉(TPS)的性质,以及热塑性淀粉和不同的合成聚合物、天然高分子共混体系的研究现状,分析了淀粉基生物可降解材料目前存在的问题,并对其今后的发展方向进行了展望。     

改性淀粉在降解塑料中的应用

降解塑料是现代包装材料的必然发展 ,淀粉基降解塑料是降解塑料的研究热点。本文在简单介绍降解塑料的基础上对淀粉基塑料的分类以及化学改性淀粉和物理改性淀粉在淀粉基降解塑料中的应用进行了重点阐述 ,以期能为淀粉基塑料的开发提供参考     

可降解淀粉基包装材料研究进展

不可降解塑料软包装废弃物所造成的白色污染正在引起世界各国的重视,其中塑料软包装材料的后处理成为关注的焦点.本文着重介绍了目前国外淀粉基可降解包装材料的种类、性能特点、制备工艺,以及高聚物/淀粉复合包装材料的发展趋势.     

淀粉塑料发展及其前景展望

<正> 塑料是应用最广泛的材料,1998年世界塑料产量约1.5亿吨,仅中国近年来包装用塑料就已超过400万吨。按其中30％为难以收集的一次性塑料包装材料和制品计算,则废弃物产生量达120万吨,如此庞大难降解“白色污染”物严重污染环境。另外,石油资源日趋枯竭,因而寻找新的对环境友好塑料原料,发展非石油基聚合物迫在眉睫。现在,美国、日本、德国等国家正大力发展降解塑料这种新型环保材料。其中以淀粉为基础原料得到生物降解淀粉塑料因其可降解、原料来源广泛、价格低廉且可再生而得到迅速发展,目前其产量已占降解塑料产量70％以上,备受人们关注和欢迎。1 国内外淀粉塑料现状1.1 国外淀粉塑料现状 淀粉塑料可分为填充型淀粉塑料和全淀粉塑料。填充淀粉塑料(含淀粉量7％～30％)曾在80年代风行一时,但     

国家计委批复变性淀粉及生物降解塑料产业化项目立项

推广使用可降解塑料和加强对废弁塑料制品回收利用是相辅相成解决“白色污染”的有效途径。天津丹海股份有限公司采用天津大学“八五”科技攻关成果淀粉超细覆羟改性技术,已达到中试生产淀粉填充型降解塑料母料及淀粉填充型降解农地膜2000吨/年生产规模。　　国家计委同意天津丹海股份有限公司建设变性淀粉超细化降解功能塑料产业化基地项目,同时将该项目列入国家重大科技成果产业化计划。　　项目建设规模与内容为,年产变性淀粉、生物降解塑料母料及功能性塑料母料3万吨;年产生物降解塑料制品及功能性塑料制品3万吨。项目总投资为19431万元…     

建立与完善降解塑料试验体系的必要性和重要性

一、背景为了解决越来越多的塑料废弃物问题，世界上相继出现了焚烧利用热能、回收再利用、自然降解等三种主要的解决塑料废弃物方法。而开发可自然降解的塑料制品来替代目前普遍使用的普通塑料制品是近年来的热点。由于各国政府、科学家、企业家的共同努力，降解塑料的开发不断取得进展，降解塑料已应用于各个行业，如降解农用塑料地膜、一次性降解餐具、降解包装材料、日用塑料、医药行业中的可降解的手术缝线等，生产降解产品的企业也越来越多。随着可降解产品的生产和需求与日俱增，为了规范可降解产品市场，保证产品的可降解性，最终保…     

可降解淀粉塑料的研究现状

塑料造成的环境污染是困扰着全世界的难题,而生物可降解塑料是解决此问题的有效途径。主要阐述淀粉基生物可降解塑料的研究现况及应用发展趋势,并依照淀粉的化学特性介绍几种常见于淀粉的改性方法。从淀粉塑料的发展、降解机理、分类等方面阐述其发展趋势与应用前景,并提出未来可降解淀粉塑料的改进及研究方向。     

用于生物降解塑料中的淀粉变性处理

本文较全面地介绍了淀粉化学变性、物理处理、接枝共聚和生物酶异构化处理技术在淀粉基生物降解塑料中的应用。为变性淀粉生产、研究单位在生物降解塑料领域变性淀粉的研发拓宽了思路。     

USDA Research on Starch-Based Biodegradable Plastics

Research on starch-based biodegradable plastics began in the 1970's and continues today at the National Center for Agricultural Utilization Research (NCAUR) in Peoria, IL. Technology has been developed for producing extrusion blown films and injection molded articles containing 50% and more of starch. Extrusion processing of compositions containing starch and other natural polymers to provide totally biodegradable plastics is being investigated. Starch grafted with thermoplastic side chains is under commercial development to provide injection molded items with a broad range of compositions and properties. The mechanism of biological degradation and the rate and extent of biodegradation of starch containing plastics in various environments is studied to enhance development and acceptance of biodegradable plastics.     

增塑体系对蔗渣基可生物降解复合材料性能的影响

利用甘油、甲酰胺和乙二醇对淀粉/蔗渣进行增塑改性,通过挤出注塑制备出了聚乳酸(PLA)/淀粉/蔗渣可生物降解复合材料。研究了增塑改性剂种类和含量对复合材料加工性能、流变性能、力学性能以及吸水性的影响。结果表明:选用的3种增塑剂对淀粉/蔗渣均有明显的增塑作用,且甲酰胺的增塑效果最好;当PLA、淀粉和蔗渣质量比为6:2:2时,增塑制得的复合材料的拉伸强度均在35 MPa以上;复合材料在4天后的吸水率均大于10%,其中由甲酰胺增塑复合材料的吸水率高达25%;增大增塑剂含量,有助于改善复合材料加工性能,但会增大复合材料的吸水率和降低复合材料的拉伸强度。     

Untersuchungen über die Retroaradation der Stärke in konzentrierten Weizenstärkegelen. Einfluß von Stärkeabbauprodukten auf die Retrogradation der Stärke

Investigations on the Retrogradation in Concentrated Wheat Starch Gels. Part 2. Effect of Starch Degradation Products on the Starch Retrogradation . In the present work the influence of added starch degradation products on the rigidity and retrogradation of 50% wheat starch gels was investigated. The gels prepared with the addition of maltodextrin were extracted with 40% ethanol, the extracts were analysed for glucose oligomers. The effect of the added starch degradation products was dependent on the degree of degradation. Weakly degraded, acid modified starches take part in the retrogradation process as do white and yellow dextrins as well as maltodextrins with dextrose equivalents (DE) <30. Maltodextrins and glucose sirups with a DE ≧ 30 act as plasticizers: in concentrations of 5-30% (based on starch d. s.) they reduce gel strength without affecting the retrogradation velocity. The plasticizing effects are particularly evident with maltose and maltotriose as well as maltotetraose and pentaose. Even so the extractibility of oligomers with a degree of polymerisation (DP) ≥ 6 was reduced, the hexamer and octamer might still have a plasticizer effect. With glucose, concentrations ≥ 26% were needed to observe plasticizing. The relation of these findings to bread staling is discussed.     

Reactivity of Modified Starches with Isocyanates

Various substituents were added onto starch by means of esterification or etherification so that their effect on reactivity of starch with isocyanates in a nonpolar solvent could be studied. Maximum reactivity of the modified starches was achieved when the degree of substitution (D.S.) was about 0.7. Cured urethane plastics made from formulations containing 20 % of the starch derivatives demonstrated maximum breaking energy at D.S. 0.7.     

热塑性淀粉的研究

通过淀粉中加入增塑剂,制备热塑性淀粉,研究了3种增塑剂的增塑效果,结果为:水>丙三醇>乙二醇。采用正交实验,确定它们之间协同作用最佳用量为:15%水、5%丙三醇、5%乙二醇。红外及X-衍射表明,淀粉经塑化后,次价键断裂、晶区被破坏,使淀粉具备热塑性。     

淀粉接枝共聚物生物降解塑料的研究

以玉米淀粉为原料，进行了淀粉化学改性，偶联，淀粉接枝共聚反应动力学的研究和生物降解塑料的工艺，配方及产品应用研究，并对淀粉接枝共聚物进行ＳＥＭ观察，显微熔点测定，生物降解试验和ＡＳＴＭ试验。建立了淀粉接枝共聚反应系统，研制成功的淀粉接枝共聚物生物降解塑料综合性能达到国际同类产品水平。     

植物基完全可降解生物塑料的现状及展望

当前环境中的塑料污染问题受到全世界关注。用于包装的塑料材料越来越多,产生大量无法降解的固体废物。生物降解塑料被认为是解决塑料废物问题的可能办法,完全可降解塑料可被微生物完全降解,起到很好的保护环境作用。植物在自然条件下可以产生淀粉、纤维素、半纤维素、储藏蛋白等聚合物,是天然的可降解高分子材料来源。以植物为基础,完全可生物降解聚合物具有完全的生物可降解性和可再生性,是替代石油基塑料的可行材料。介绍解决塑料污染问题的可能办法及主要几种植物基完全可生物降解塑料研究现状和发展前景。     

Sorption isotherm and plasticization effect of moisture and plasticizers in pea starch film

Pea starch films were produced with various plasticizers (glucose, fructose, mannose, sorbitol, and glycerol). Effects of plasticizer content (4.34 to 10.87 mmol/g of dry starch) and storage relative humidity (RH) (11.3% to 75.4%) on moisture content (MC), tensile strength (TS), elongation (E), modulus of elasticity (EM), and water vapor permeability (WVP) were evaluated using response surface methodology. MC was influenced strongly by RH. Glycerol-plasticized films had the highest MC, indicating that water molecules played a more important role in plasticizing starch films. Monosaccharide-plasticized films and polyol-plasticized films had similar TS values. However, monosaccharide-plasticized films had higher E values and lower EM values than polyol-plasticized films, meaning monosaccharides had better efficiency in plasticizing starch films. Recrystallization happened in glucose- and sorbitol-plasticized films when they were stored in high RH. Sorption isotherm studies showed the similar adsorption and desorption profiles for all 3 monosaccharide-plasticized films and a hysteresis. The Flory-Huggius model fitted experimental data best for starch films, while the BET model fitted the data marginally.     

New Directions for Starch and Glucose Research

Enzymes have become a prime commercial tool for modification of starch and glucose. Today we see enzymes used to convert starch to glucose and again to convert glucose to a mixture of glucose and fructose, invert sugar in the terminology of cane and beet sugar manufacturers. We will expect to see greater use of enzymes to modify starch granules to produce a new way of dextrinization of starch. Enzymes may also be used to modify starch molecules to increase the degree of branching producing new properties among which can be those giving solutions of low viscosity, but high solids contents. Starch or glucose derivatives can also be sources of sugar for derivatizing protein to produce glycoproteins a potential new class of water soluble gums or food additives. Low caloric sweetners are possibly by more extensive modification of glucose similar to thio-glucose or sugar sweetner attached to nondigestible polysaccharides such as cellulose. Isomerization of glucose to fructose can provide crystalline fructose which may find wider use in special diet foods. Appropriate derivatization of starch could produce polymers compatible with pure synthetic plastics in which they could act to modify and improve plastic properties.