塑料食品包装用生物基添加剂研究进展

目的 介绍塑料食品包装用生物基添加剂的研究现状,为选择和使用包装用安全、绿色环保的生物基添加剂提供一定的参考和依据.方法 通过查阅并分析总结文献,综述塑料食品包装用生物基添加剂的分类、特性及应用范围,并根据生物基添加剂的原料类别将其分类.结果 塑料食品包装用生物基添加剂主要包括生物基增塑剂、抗菌剂、抗氧剂,相较于传统添加剂,生物基添加剂因其独特的可再生性,将成为添加剂可持续发展的重要途径之一.结论 生物基添加剂正处于快速发展阶段,随着国家对绿色环保包装、可降解包装的重视,以及随之颁布的"禁塑令",将有望实现对传统添加剂的有效替代,其在塑料食品包装方面的应用前景和发展具有巨大潜力.     

木质纤维素类生物基材料研究进展

木质纤维素类生物质作为重要的可再生资源,不仅可以转化为能源及化工品,还可以合成相关的生物基材料。本文综述了以木质纤维素类生物质各组分为原料合成的生物基材料的种类、方法和应用,发现生物质是很好的化石材料替代品。直接将生物质各组分进行生物基材料合成会缩小其应用范围,运用化学改性方法对生物质各组分进行化学改性后再合成生物基材料,可以优化材料的一些性能,其中,基于生物质绿色、可降解和无污染的天然特性,在污水处理和替代相关石油基材料的原料方面其将发挥更重要的作用。     

An overview of mechanical properties and durability of glass-fibre reinforced recycled mixed plastic waste composites

In recent years, there has been an increasing interest in seeking the potential applications of recycled mixed plastic wastes in building and construction sectors to relieve the pressure on landfills. This paper presents the recent developments and applications of composite materials made from recycled mixed plastics and glass fibre. Some of the first uses for such composites are as an alternative to non-load bearing applications like park benches and picnic tables. With its inherent resistance to rot and insect attack, these composites can in fact be used as a replacement for chemically treated woods in various larger-scale outdoor applications such as railroad crossties and bridges. However, the properties of the structural components made from recycled mixed plastics are not well understood. Information on the behaviour of such composites under applied loading and at different environmental conditions such as elevated temperature and ultraviolet rays are crucial for the utilisation of recycled mixed plastic materials in construction. This paper presents an overview of the mechanical properties and durability of recycled mixed plastic waste composites. The paper identifies research needs critical in the effective design and utilisation of these composite materials in civil engineering and construction.     

泡沫塑料包装衬垫缓冲性能建模

本文从非线性粘弹性物质的多重积分型本构方程出发,引入塑性应变,推导了粘弹塑性物质的微分型本构方程.进一步考虑材料的损伤特性,建立了泡沫塑料包装衬垫的缓冲性能模型.根据在一种跌落高度、衬垫厚度和静态应力组合条件下的国产可发聚苯乙烯沫泡塑料的连续多次跌落冲击试验数据,识别了其缓冲性能模型参数.动力学计算与试验结果的比较表明,该模型能较好地反映可发聚苯乙烯泡沫塑料包装衬垫在连续多次跌落冲击过程中的加速度、速度、位移变化,冲击能量的吸收性和塑性变形等基本特性.并且仅根据在一种组合条件下的试验数据所识别的这一模型,在其它组合条件下其缓冲性能与试验结果也吻合较好.     

食品接触材料中有害物质迁移的研究进展

目的 综述目前食品接触材料中几种常用材料(纸、塑料、油墨)迁移与检测的研究进展,并指出几种材料未来的发展趋势,促使我国食品行业向着更绿色、更安全的方向发展。方法 概述纸质、塑料、油墨的发展趋势和材料中有害物质的来源;对比几种材料的迁移规律及迁移模型;总结几类常见有害物质的检测方法。结论 绿色环保的生物基材料是食品接触材料未来的发展方向,同时也需重视可持续性生物基食品接触材料的化学安全性。因其产生的化学品对人体健康的影响不甚明朗,因此需多方面研究生物基食品接触材料中化学物质的存在和迁移到食品中的情况,并采取相应措施减少包装材料的使用,降低材料中有毒有害物质对人体和环境的威胁。     

生物基全降解复合材料

淀粉/聚乳酸复合具有相对较好的力学性能和生物降解性能,价格也与石油基塑料最为接近,是极具应用前景的全生物降解塑性材料。在分析国内外聚乳酸、淀粉及其复合材料研究现状的基础上,对该类材料的技术发展方向和工业化前景进行了展望。     

Harakeke (phormium tenax) fibre–waste plastics blend composites processed by screwless extrusion

Most plastic packaging products are discarded after a single use resulting in an abundant supply of waste plastics. Natural fibres are light in weight, abundant and inexpensive. The stiffness and strength of polymers have been shown to improve with the incorporation of natural fibres. Hence, composite materials made of natural fibres and waste plastics would result in the reduction of plastic wastes and the use of fibres from renewable resources. Composite specimens and sheets consisting of fibres from the New Zealand flax plant, phormium tenax or Harakeke as it is known in Maori, and waste plastics have been produced through screwless extrusion followed by injection moulding. The tensile and impact properties of these composites have been determined. The formability of these composites has been assessed through thermoforming.     

绿色包装材料研究进展

目的 为更好地推动绿色包装材料的研发及利用,综述以纸包装、金属包装、玻璃包装和可降解塑料包装为代表的绿色包装材料的研究进展,以及国内外针对不同类型材料的回收体系。方法 主要总结可降解材料在应用方面存在的一些问题和不同降解机理材料之间存在的差异,介绍4种绿色包装材料的市场地位和回收系统的改进措施。结果 目前绿色包装材料的制造工艺及回收体系仍有较大的改进空间,开发经济型的环保材料并改进材料回收处理工艺对当今环境污染的防治具有重要意义。结论 传统包装材料会持续占有较大市场份额,随着可降解材料研究的深入或将逐步代替传统塑料,成为未来的主流包装材料。     

生物质材料对微纳塑料吸附性能的研究进展

废弃塑料在江河湖海中呈累积趋势，老化分解产生的微纳塑料严重污染水质，威胁生态环境和居民饮用水安全。传统处理方法，如物理絮凝、生物降解等，存在处理周期长、吸附效率低等问题。天然生物质含有大量的羟基、羧基等活性基团，对生物质进行物理处理或化学修饰改性能够改善孔隙结构和提高比表面积，可作为吸附微纳塑料的绿色材料。本文从微纳塑料的常规处理方法和基本特征出发，简要概况了不同类型微纳塑料对植物、动物和人体的潜在影响和危害，系统介绍了生物质材料(生物质炭、纤维素、甲壳素等)在微纳塑料吸附领域的研究现状，分析总结了生物质材料对微纳塑料的吸附行为、规律和作用机制，最后展望了生物质材料吸附微纳塑料的未来发展前景。      

Cavitation Instabilities in Plastics and Rubber-Modified Plastics

Spherical void expansion in plastics and rubber-modified plastics is investigated under radial traction conditions. The plastics are modeled as elastic-plastic pressure-sensitive materials and the rubbers are modeled as nonlinearly elastic materials. First, the growth of a spherical void in an infinite plastic matrix is investigated under remote radial traction conditions. The results show that the cavitation stress of the plastic decreases significantly as the pressure sensitivity increases. Then, the growth of a spherical void located at the center of a spherical rubber particle in an infinite plastic matrix is investigated under remote radial traction conditions. The results indicate that without any failure criteria for the rubber, the cavitation stress does not exist when the void is small and the rubber is characterized by high-order strain energy functions. However, when a failure criterion for the rubber is considered at a finite stretch ratio, the results show that the cavitation stress for the plastic with the rubber particle becomes close to that for the plastic without the rubber particle. This revised version was published online in August 2006 with corrections to the Cover Date.     

Über Korrosionserscheinungen,ausgelöst durch duroplastische Formstoffe (Teil 2) – Elektrolytische Korrosion

Investigations on corrosion caused by therm osetting materials (part 2) Electrolytic corrosion . Electrolytic corrosion on metallic materials is caused by plastics under the influence of a direct voltage. This second part of the investigations on plastic corrosion deals with the characteristic qualities of thermosetting materials, responsible for such type of corrosion. These qualities may be determined by the composition of the plastics and by the curring conditions. Measuring the insulation current in the plastic specimen gives an indication to the corrosive effect. It is shown by measuring the insulation current in longtime tests with varying materials and test conditions that short-time tests may give a conclusive statement on the corrosiveness of plastics.     

跨境再生HDPE生产塑料罐包装的碳足迹评价研究

目的 探索塑料包装的碳足迹评价技术,建立健全该行业碳足迹改进的技术方法.方法 运用生命周期评价法,对塑料罐包装的碳足迹建模、数据采集和计算结果进行分析,并讨论关联因素的影响;基于碳足迹评价结果,提出评价对象生命周期碳足迹的改进方案.结果 研究发现系统边界内单件20 L塑料罐包装的碳足迹为2.48 kg-CO2-eq;再生料改性、吹塑成型的碳足迹贡献度达17.5％,75.8％;新料使用的单项碳足迹达1.02 kg-CO2-eq,再生料质量分数增加5％,碳足迹下降了7.67％;单位容积碳足迹随着包装容积增大而减小.结论 由于原生资源消耗量的减少,再生塑料资源的利用,可以明显改善包装生产的物料和电力碳足迹;同配比下大体积规格的包装设计对于提高单件包装的利用效率起到积极作用;跨境再生料的使用、合理包装设计、绿色电力应用等均是改善塑料罐包装碳足迹的有效方案.     

Fortschritte in der technischen Anwendung von Kunststoffverbundsystemen

Progresses in the application of plastic compound materials Plastics possess a number of various properties one cannot find in another material in this combination. Beyond that the desired properties can be reached by compounding several different materials. The best known example is the glass reinforced plastic. The arguments for the application of compound materials are very different: increase of strength and stiffness, cheaper injection moulded parts due to shorter cycle times, thinner wall-thicknesses and therefore less raw material consumption, lower distortion and thermal elongation for technical parts and excellent thermal insulation of the foams. Research on the topic of the bonding between the plastic and the carbon, glass and organic fibres led the way to an ever spreading field of the application of reinforced plastics.     

Fractography of metals and plastics

Fractography is critical to failure analysis of metals and plastics. Fractography of plastics is a relatively new field with many similarities to metals. Using case histories, various aspects of failure analysis and fractography of metals and plastics are compared and contrasted. Failure modes common to both metals and plastics include ductile overload, brittle fracture, impact, and fatigue. Analogies can also be drawn between stress-corrosion cracking (SCC) of metals and stress cracking of polymers. Other metal/plastic failure analogies include corrosion/chemical aging, dealloying/scission, residual stress/frozen-in stress, and welds/knit lines. Stress raisers, microstructure, material defects, and thermomechanical history play important roles in both types of materials. The key fractographic features for metals and plastics are described in this paper.     

绿色塑料包装材料的进展

介绍了开发塑料包装材料绿色化技术的重要性,阐述了绿色塑料包装材料的进展。     

Kunststoffe in der Gelenkendoprothetik

Use of Plastic Materials for Joint Endoprotheses The use of plastic materials for joint endoprothetic components such as hip joint sockets, tibia plateaus and femur shafts as well as for the fixation of these components in human bones has meanwhile become common practice, and though the technological standard in this field is undoubtedly very high, it must be admitted that the extremely high biological-medical, constructional and material lrequirements still leave a lot of wishes unfulfilled. Based on the human joint and some characteristics of the human bone the current state of the use of plastic materials for joint endoprotheses is described and evaluated. Besides this, proposals are made for the further improvement of ultra high molecular eight polyethylene (UHMWPE) and bone cements based on polymethylmethacrylate (PMMA) with regard to both the materials themselves and their treatment. Current developments in fields like bioactive and porous coatings and the reinforcement of basic materials are briefly explained. In the author's opinion there are a number of measures by means of which it should be possible to gradually improve the UHMWPE. The developments that have so far been made in the field of carbon fibre reinforced plastics (CFP) and their application for endoprotheses are very encouraging and promising for the future. In spite of most intensive developmental work aimed at improving bone cements, a real break-through to new systems has not yet been made. With optimum surgical methods and technologies the reliability of the fixation is, however, nevertheless very high. This is true likewise for the cement-free fixation of endoprotheses. In this field it seems that the use of porous coatings and surgical technologies are coordinated in an optimum manner.     

静电纺丝制备生物基食品活性包装纤维膜及其应用

目的 将具有电纺性的生物基材料应用在食品包装领域,为静电纺丝技术在食品活性包装纤维膜制备中的应用提供参考和依据.方法 对静电纺丝技术的原理、优势进行分析,归纳蛋白质、多糖等生物基大分子材料的可纺性、由不同材料复合制得纳米纤维膜的特性和功能差异,以及静电纺丝技术制备生物基食品活性包装纤维膜及其在抗菌、抗氧化、功能吸收包装等方面的应用,并对该技术在食品活性包装中存在的问题和发展前景进行展望.结果 静电纺生物基纳米纤维膜可用作食品活性包装,具有良好的贮存与保鲜效果.结论 静电纺丝具有工艺简单、成本较低等优点,且制得的纳米纤维膜比表面积大、纳米尺度效应明显,已成为一种非常便捷的制备功能活性食品包装材料的微纳制造技术;再结合生物基大分子材料在安全、无毒、可降解、可食用等方面的优势,其在食品包装领域具有良好的发展前景.     

Parametric Design and Optimisation of Thin-Walled Structures for Food Packaging

In this paper the parametric design and functional optimisation of thin-walled structures made from plastics for food packaging is considered. These objects are produced in such vast numbers each year that one important task in the design of these objects is to minimise the amount of plastic used, subject to functional constraints, to reduce the costs of production and to conserve raw materials. By means of performing an automated optimisation on the possible shapes of the food containers, where the geometry is parametrised succinctly, a strategy to create the optimal design of the containers subject to a given set of functional constraints is demonstrated.     

生物可降解高分子材料增韧共混改性研究进展

目的 综述国内外生物可降解塑料共混改性的常用策略,为高品质生物可降解塑料的工业化开发提供思路与理论方法。方法 共混改性是高分子材料改性的常用策略,因其具有高效、经济的特点而被广泛采用,本文针对生物可降解高分子材料增韧共混改性策略,选取聚乳酸（PLA）、对苯二甲酸-己二酸丁二醇酯（PBAT）、聚丁二酸丁二醇酯（PBS）作为对象,对增韧共混改性研究现状进行归纳、总结和分析,同时对比各自的增韧改性效果及优点和不足。结论 以生物可降解塑料取代不可降解塑料可以在很大程度上缓解当前的环境污染问题,在未来地膜和包覆材料中具有广阔的应用前景。     

Developments and applications of recycled plastics

Plastics in the waste stream have increased steadily, from about one-half million tons in 1960 to 9.6 million tons in 1984 in the United States; if this trend continues, the amount of plastic wastes in the year 2000 will be 15.5 million tons. The problems associated with the growing proportion of plastic packaging materials in community domestic refuse have generated public concerns. Furthermore, an increasing number of laws are being proposed to address the solid waste — many targeted at plastic packaging. This was the background for the conference?Recycled Plastics: Developments and Applications’?which provided a broad perspective of the field. Emphasis was placed on current and potential uses for recycled plastics. The conference was held on September 15, 1987 at the School of Packaging, Michigan State University. More than a score of speakers examined the latest developments and discussed recycling methodologies, marketing approaches, social and environmental implications. This brief report attempts to summarize the main points made.