淀粉塑化机理研究进展

可降解淀粉塑料是目前新材料发展一个热点,由于天然淀粉热塑性差,难以直接加工成淀 粉塑料,因此淀粉塑化处理成为淀粉可降解塑料生产关键技术。本文综述淀粉的物理、化 学及热塑性改性的增塑机理,从而为共混型淀粉降解塑料或全淀粉降解塑料的生产提供 理论参考。     

生物降解高分子材料的研究及发展

本文介绍了生物降解过程及生物降解高分子的种类,阐述了淀粉基生物降解塑料、聚乳酸树脂、改性大豆蛋白塑料等环境友好型生物材料的研究现状,指出了我国研究发展生物降解高分子材料的现实意义。     

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。     

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。     

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     

淀粉基生物降解塑料研究进展

该文综述当今淀粉基生物降解塑料分类、研究方法、发展状况,及淀粉基生物降解塑料发展中存在一些问题和应用前景。     

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.     

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…     

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。     

淀粉基生物降解塑料的研究进展

我国淀粉资源丰富、价格低廉，淀粉作为可完全生物降解的天然高分子材料日益受到人们的重视。本文综述了当今淀粉基生物降解塑料的分类、研究方法、发展状况，以及当今淀粉基生物降解塑料发展中存在的一些问题和应用前景。     

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。     

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.     

淀粉基可食膜性能及其影响因素的研究进展

淀粉基可食膜是以淀粉或改性淀粉为主要原料，添加填充物和少量功能成分(抗菌剂/抗氧化物)通过干法或湿法等工艺制成的高分子薄膜，具有生物可降解性和可食性等优点。然而，由于淀粉膜力学性能、阻隔性能等相比传统塑料更差，因此探究淀粉膜性能的影响因素及优化工艺将成为重点研究方向。本文综述了淀粉基可食膜的性能、淀粉的结构性质、加工助剂、淀粉改性等对其性能的影响及机制，并概述了淀粉基可食膜应用前景及存在的问题，展望了其发展前景，为进一步开发具备优良性能的淀粉基可食膜提供参考。     

Developing Biodegradable Mulch Films from Starch‐Based Polymers

This paper examines the development of starch‐based plastics for use as biodegradable mulch film. A variety of starch‐based polymers are blended with high performance biodegradable polyester polymers in order to determine the applicability of films to be processed on a film blowing line and to perform well in mulch film field trials. The process of material formulation, film blowing processing and scale‐up and performance properties are highlighted for a successful material. Insights into future developments of starch‐derived biodegradable polymers are given.     

On the Mechanical Properties of Native Starch Granules

As a fundamental prerequisite for starch based material development, we set up a method to determine mechanical properties of native starch granules. Instead of measuring tiny single granules, we developed an indirect procedure. It relies on a verified composite material theory and simple tensile tests with starch filled plastics. Resulting data for native potato starch granules: elastic modulus 2.7 GPa, tensile strength 60 MPa, indentation hardness 113 N/mm². These data are similar to those of rigid thermoplastics.     

Effect of Reaction Conditions and Alkyl Chain Lengths on the Properties of Hydroxyalkyl Starch Ethers

Starch applications in the plastics industry have been investigated intensively for many years. Unfortunately, native starch is unsuitable for most applications in polymers, because of its hydrophilic and brittle character. Modification of native starch can be a solution of this problem. In our research programme we developed an environmentally friendly process for the preparation of starch derivatives with long hydrophobic side chains based on natural products derived from vegetable fats and oils on the one hand and amylomaize starch on the other hand. In this process modification is carried out by the addition of longchain 1,2‐epoxyalkanes (chain lengths varying between 6—18 C atoms) to starch in an alkaline aqueous medium. Reaction yields and molar degrees of substitution depended on chain length, reaction time, temperature and catalyst concentration. Under optimised reaction conditions molar degrees of substitution of hydroxyalkyl starch ethers for theoretical molar substitution (MS) = 3.0 decreased from MS=1.8 (C₆ starch ether) to MS=0.2 (C₁₈ starch ether), respectively. Hydrophobic properties of starch products were measured in order to reveal structural effects obtained at different reaction conditions. Water solubility and water absorption properties of hydroxyalkyl starch ethers decreased with increasing chain length and number of hydroxyalkyl substituents. Thermal and thermoplastic properties of starch ethers were investigated in order to determine their potential use as biodegradable polymers in the plastics industry. As expected, thermoplasticity of starch ethers increased with increasing MS and increasing chain length of the hydroxyalkyl side groups.     

木素制可降解塑料的研究

以木质素、25%的甘油共混造粒,造粒后的木质素与淀粉母料、聚乙烯共混挤出制备55%的木质素基塑料.研究了木素/淀粉/聚乙烯共混物的流变特性、力学性能和降解性.流变特性表明共混物可加工性,添加淀粉母料的共混物的力学性能有所降低而降解性加快.     

Casting and extrusion processes to produce bio-based plastics using cassava starch modified by the dry heat treatment (DHT)

Although the number of studies focused on bio-based plastics is constantly rising, an important challenge to overcome is migrating from casting to extrusion, an industrially scalable method of production. In this work, we studied starch modification by dry heating treatment (DHT) and the production of cassava starch films or sheets, by casting or extrusion processes, respectively. The molecular changes promoted by the DHT process resulted in a new matrix. Furthermore, the slower drying in casting, and the faster drying in extrusion, promoted different molecular arrangements, which affected the material performance. The main results showed that DHT for 4 h in cassava starch produced bio-based plastics with increased mechanical properties and opacity while decreasing water permeability, moisture content and light transmittance. In conclusion, DHT showed to be an interesting alternative to produce biodegradable plastics with potential use in different industries.     

Global Status of the Production of Biobased Packaging Materials

Bioplastics from renewable origin are a new generation of plastics able to significantly reduce the environmental impact in terms of energy consumption and green‐house ef‐fect in specific applications. Bioplastics perform as traditional plastics when in use and are completely biodegradable within a composting cycle. Today bioplastics and partic‐ularly starch‐based plastics are used in specific industrial applications where bio‐degradability is required. Examples are composting bags and sacks, fast food service‐ware (cups, cutlery, plates, straws, etc.), packaging (soluble foams for industrial pack‐aging, film wrapping, laminated paper, food containers), agriculture (much films, nur‐sery pots, plant labels), hygiene (diaper back sheet, cotton swabs).Moreover new sec‐tors are growing outside biodegradability, driven by improved technical performances of bioplastics versus traditional materials, as in the case of biofillers for tires. The market of starch‐based bioplastics in 1999 has been estimated at about 20,000 t/a, with a strong incidence of soluble foams for packaging and films. Bioplas‐tics from renewable origin, either biodegradable or non‐biodegradable, still constitute a niche market which requires high efforts in the areas of material and application devel‐opment; the technical and economical breakthroughs achieved in the last three years, however, open new possibilities for such products in the mass markets and specifical‐ly in food packaging. This paper will review the recent industrial achievements of bioplastics in the sector of packaging, taking in consideration their in‐use performances, biodegradation behav‐iour and environmental impact.