Life cycle assessment of functional materials and devices: Opportunities,challenges, and current and future trends

Functional ceramics such as piezoelectrics, thermoelectrics, magnetic materials, ionic conductors, and semiconductors are opening new frontiers that underpin numerous aspects of modern life. This widespread usage comes with a responsibility to understand what impact their mass production has on the environment. Life-cycle assessment (LCA) is a tool employed for the identification of sustainable materials pathways through the consideration of environmental burdens of materials both during fabrication and as a final product. Although the LCA technique has been widely used for the evaluation of environmental impacts in numerous product supply chains, its application for environmental profiling of functional ceramics is now gaining attention. This paper presents a review of current developments in LCA, including existing and emerging applications with emphasis on the development and fabrication of functional materials and devices (FM&D). Selected published works on LCA of functional ceramics are discussed, highlighting the importance of adopting LCA at the design stage and/or at laboratory stage before expensive investments and resources are committed. Drawing from the extant literature, we show that the integration of environmental and sustainability principles into the overall process of FM&D manufacturing, in a way that anticipates foreseeable harmful consequences while identifying opportunities for improvement, can aid the timely communications of key findings to functional materials developers. This guides the orientation of research, development and deployment, and provides insights toward the prioritization of research activities while potentially averting unintended consequences. It is intended that the review presented will encourage the materials science community to engage with LCA to address important materials design, substitution, and optimization needs.     

Additive sustainability footprint: Rationale and pilot evaluation of a tool for assessing the sustainable use of PVC additives

PVC compounds contain additives necessary for processing and stability, and to modify the plastic's properties. The Europe‐wide VinylPlus® voluntary commitment includes a challenge to make progress toward sustainable use of additives. Additive Sustainability Footprint (ASF) was developed to assess sustainable use of additives across the whole societal life cycles of finished PVC articles, taking a risk‐based approach rather than simplistic hazard assessment. ASF addresses impacts across six life cycle assessment (LCA) stages established by ISO Standard 14040, using the four System Conditions (sustainability principles) developed by The Natural Step (TNS) covering social as well as environmental factors. For each LCA stage/System Condition combination, seven generically similar questions cover negative impacts (many covered by existing tools and regulations) but also the additive's positive contributions to the sustainability of finished articles. Positive contributions include ethical sourcing, longevity of service life, low maintenance inputs, and recyclability. Answers to questions determine a score, which can be combined across the life cycle and with other additives. Testing on a generic EU PVC window profile supported ASF development and demonstrated applicability and potential benefits including use for sensitivity analysis of alternative additives from different geopolitical regions or from recycled as opposed to virgin sources. J. VINYL ADDIT. TECHNOL., 26:196–208, 2020. © 2019 Society of Plastics Engineers     

A life‐cycle assessment (LCA) model for cables based on the fire‐LCA model

A novel life‐cycle assessment (LCA) model has been developed for the investigation of the environmental impact of the choice of material in cable production. In the first application polyolefin based material and PVC material is used. In both cases equivalent fire behaviour is assumed and a fire model is established based on existing fire statistics. This study represents the second full application of the fire‐LCA model. In this paper the new ‘cables fire‐LCA’ model will be presented together with the results of this first application. Aspects such as end‐of‐life scenarios, fire statistics, and fire scenarios and large scale fire performance of cables are discussed together with details of the straw LCA model defined for cables and the results of four different end‐of‐life scenarios. Copyright © 2003 John Wiley & Sons, Ltd.     

茂金属基聚烯烃泡沫塑料

本文介绍一种生产聚烯烃泡沫塑料块料的独特的氮气热压罐工艺。最新的产品开发包括茂金属基催化聚烯烃泡沫塑料。文章对这些材料的性能和可能的用途进行了讨论     

官能化聚烯烃的进展和应用

官能化聚烯烃是由聚烯烃改性后得到的产物,一般通过交联改性、共聚改性、固相力化学改性和接枝改性等方法制备,可应用于黏附、能源和封装等多重领域。基于聚烯烃高通量低成本的优势,聚烯烃接枝改性利用自由基反应直接向聚烯烃链上引入极性单体,较为经济便捷。聚烯烃接枝改性按反应条件的不同,又可分为溶液接枝、熔融接枝、辐射接枝、固相接枝和悬浮接枝。在接枝改性过程中,接枝率和接枝效率受多种因素影响,如聚烯烃型号、接枝单体、引发剂、共单体和反应条件等。本文综述了聚烯烃接枝改性不同接枝方法的研究进展,分析了各种接枝方法的优势和短板,并将接枝改性过程中的影响因素进行了总结。文章依据聚烯烃的可控自由基接枝改性和金属催化改性以及官能化聚烯烃的应用,展望了聚烯烃可控改性和官能化聚烯烃规模化生产。     

基于静电分选解析聚乙烯颗粒生长与形貌演变

解析聚烯烃颗粒生长过程的形貌演变规律对认识聚合反应机理和调控产品性能至关重要。然而,聚烯烃复杂的颗粒生长行为导致极宽的粒径分布和较大的形貌差异,现有研究关注形貌均一的催化剂破碎生长成初级聚烯烃的过程,缺少对形貌各异的初级聚烯烃后续生长和形貌演化的系统研究。此外,亟需一种能够批量分选不同形貌聚烯烃的手段,支撑聚烯烃颗粒生长形貌的统计解析。基于同质同粒径颗粒摩擦荷电的形貌依赖性,开发了聚烯烃颗粒静电-形貌协同分选技术,实现了尺寸相近的不同形貌聚烯烃颗粒的批量分选,并基于此考察了聚乙烯颗粒生长过程中形貌的分化与演变规律。结果显示,聚乙烯颗粒生长过程中存在普遍的形貌劣化现象,随着粒径增大,颗粒形貌逐渐偏离标准球形;颗粒粒径、形貌、结晶度等的耦合解析表明聚乙烯颗粒存在两种可能的颗粒生长模式和形貌劣化路径：结晶速率过快导致的颗粒破碎和催化剂形貌复制效应导致的形貌劣化。研究方法和结果可为聚烯烃形貌研究和开发高性能聚烯烃催化剂提供重要支撑。     

Compositional analysis of thermoplastic wood composites by TGA

A method has been developed for the quantitative determination of the composition of thermoplastic wood composites. The method involves area measurements of the two peaks in the derivative curve of a tracing produced by the thermogravimetric analysis (TGA) of a thermoplastic composites sample in an inert atmosphere. This may involve the standard, constant heating rate method or the high resolution (Hi‐Res?) TGA method; both produce virtual baseline separation between wood and polyolefin peaks over a wide compositional range. Because this baseline separation suffers from a mutual effect on the thermal degradation of wood and polyolefins, best results are obtained if the parameters relating peak area with polyolefin content are different below and above 40% polyolefin content. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1484–1492, 2004     

烯烃类聚合物的改性

本文讨论了烯烃类聚合物化学改性的新发展,分别论述了烯烃聚合物熔证和非熔融状态下的改 ,搪塞了不同材料对烯烃聚合物的改性机理及改性效果。     

Environmental life cycle assessment of a pre‐fragmented high explosive grenade

Organisations today face increasing environmental constraints, e.g. in the form of legal and customer requirements; the defence sector is no exception. There is a need to evaluate and limit environmental effects of defence activities and materiel. In this study we used quantitative Life Cycle Assessment (LCA) and a method for simplified LCA (the Material, Energy, Chemicals and Others (MECO) method) to assess the environmental impacts of a grenade. The aims of the study are to identify aspects in the grenade's life‐cycle that have the largest environmental impact, suggest improvement possibilities, make a comparison between different approaches for waste management of munitions, and to perform a demonstrative case for the application of LCA to munitions. Significant environmental aspects of the grenade's life‐cycle include use of metals, use of fossil fuels, and detonation outdoors. The study shows that an LCA can be used to analyse environmental impacts from munitions. The simplified LCA gave information that is complementary to the quantitative LCA. Copyright © 2005 Society of Chemical Industry     

木质素/聚烯烃复合材料界面增容的研究进展

木质素作为植物界第二大可再生生物质资源,其有效利用技术一直是人们关注的热点。利用共混技术制备木质素/聚烯烃复合材料不仅可以提高木质素的有效利用率,还可以减少化石能源的消耗,提高聚烯烃的环境适应性,是近年来研究的热门课题。然而聚烯烃和木质素之间的界面黏附能力差,直接影响复合材料的性能,因此改善两者的界面相容性对于提升木质素/聚烯烃复合材料的性能至关重要。本文介绍了木质素的结构与性能,分析了木质素与聚烯烃相容性差的原因,同时从增容方法和共混工艺两方面回顾了国内外在木质素/聚烯烃复合材料界面增容方面的研究现状和最新进展,着重阐述了增容剂种类、木质素改性方法、共混工艺参数的改变对复合材料界面相容性的影响。此外,在木质素/聚烯烃复合材料生产生活应用的基础上展望了木质素/聚烯烃复合材料界面增容的发展趋势,指出进一步寻找成本低廉、性能优异的增容剂,探索更有效的复合增容工艺以及引入能量牺牲键将是未来研究的主要方向。     

Introducing quantitative life cycle analysis into the chemical engineering curriculum

This paper briefly describes the various stages used to perform the life cycle analysis (LCA) of a product or process. The analysis is simplified in its outputs in that it focuses only on energy usage and carbon and sulfur dioxide emissions. The main point however, is to provide examples to first year engineering and science students that illustrate the principle of LCA without the need for extensive spreadsheet analysis that is so often required. Two examples are given and are staged in their complexity. Firstly, the task of choosing which option for drying hands after washing is explored. Air drying, washable cloth towel and disposable paper towels are assessed based on their carbon dioxide emission. This example provides a quantitative approach to determining impacts as well as an introduction to creating flowsheets and manipulation of unit equations. The second example, dealing with the location of a manufacturing plant, extends the LCA approach to sulfur dioxide impacts at both a local and global scale. It introduces the not-in-my-back-yard (NIMBY) concept and how this might be overcome by an optimisation (minimisation) of impacts at both local and global scales.     

聚烯烃塑料的热解和催化热解研究进展

通过热解和催化热解技术将废塑料转化为高附加值产品是一种有前途的回收途径,可解决废塑料对环境的污染问题并促进环境的可持续化,这种方法同时具有经济效益和明显的环境优势,为塑料的回收行业确立了未来的发展趋势。本文以石蜡、轻质芳烃（BTX）、低碳烯烃和苯乙烯等产品为出发点,阐述了不同聚烯烃塑料的热解特性,详细介绍了温度和停留时间对产品分布和收率的影响,然后基于聚烯烃空间结构的差异,讨论了不同催化剂作用下的热解机理,并对催化剂的酸强度和孔结构等影响因素进行了着重分析,以改善产品选择性。此外,文章简述了聚氯乙烯脱氯的三类过程,即热解脱氯、催化热解脱氯和吸附脱氯。最后指出催化热解过程中催化剂成本高、重复使用活性低等潜在问题,今后的研究应致力于优化工艺路线、开发价格低廉的新型催化剂。     

国内外聚烯烃技术进展与市场分析

综述了国内外聚烯烃生产技术新进展以及市场供需状况,重点分析了我国聚烯烃产业的供需现状及预测。目前,我国聚烯烃的自给率达60%左右,国内市场仍有较大缺口,但国外大量的进口产品对国内产品形成了较大的冲击。为提高国内产品的市场份额,建议国内聚烯烃生产企业应增加科技投入,提高技术水平,降低生产成本;增加产品牌号,提高产品质量,进一步占据聚烯烃产品的高端市场。     

化工产品的生命周期成本分析

生命周期成本分析(LCC) 和生命周期评价(LCA)是实现化工产品设计和过程清洁生产的两大支持工具。引入环境成本概念,分析了生命周期成本的构成,重点分析生命周期成本分析法的步骤,并提出采用LCC和LCA进行化工产品设计的概念框架及实施步骤,为化工产品设计提供科学定量的决策依据。     

Sustainable process design by the process to planet framework

Sustainable process design (SPD) problems combine a process design problem with life cycle assessment (LCA) to optimize process economics and life cycle environmental impacts. While SPD makes use of recent advances in process systems engineering and optimization, its use of LCA has stagnated. Currently, only process LCA is utilized in SPD, resulting in designs based on incomplete and potentially inaccurate life cycle information. To address these shortcomings, the multiscale process to planet (P2P) modeling framework is applied to formulate and solve the SPD problem. The P2P framework offers a more comprehensive analysis boundary than conventional SPD and greater modeling detail than advanced LCA methodologies. Benefits of applying this framework to SPD are demonstrated with an ethanol process design case study. Results show that current methods shift emissions outside the analysis boundary, while applying the P2P modeling framework results in environmentally superior process designs. Future extensions of the P2P framework are discussed. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3320–3331, 2015     

Utilization of Recycled Polypropylene for Production of Eco-Composites

Renewable raw materials and recyclable thermoplastic polymers provide attractive eco-friendly quality as well as environmental sustainability to the resulting natural fiber reinforced composites. We studied the possibility of using the recycled polypropylene (PP) for production of composites based on kenaf fibers (KF) and rice hulls (RH) as reinforcements. Polypropylene/rice-hulls (PP/RH/CA) and polypropylene/kenaf (PP/K/CA) composites with 30% fiber (filler) content and appropriate compatibilizing agent (CA)—a maleic anhydride grafted PP (MAPP), have been prepared by two steps procedure: melt mixing and compression molding. Flexural strength and thermal stability of the composites with recycled PP were similar to those with neat PP. The composites reinforced with kenaf fibers have shown better properties than those based on rice hulls. The flexural strength of the composite sample with recycled PP is 51.3 MPa in comparison with 51.1 MPa for the composite with neat PP. Degradation temperatures of neat and composite with recycled PP at residual weight 90% are 344.4°C and 343.5°C, respectively. The results obtained report the possibility of utilization of recycled PP for the production of natural reinforcements based composites with good mechanical characteristics for using as construction building materials in housing systems.     

Accelerating the degradation of polyolefins through additives and blending

Polyolefins are popular because of their low price, useful properties, broad supply chains, and mature processing facilities, but they do not easily degrade in the natural environment, and hence, the development of degradable polyolefins has attracted increasing interest. Oxidative degradation and blending with natural polymers can accelerate the degradation of polyolefins in natural environments. In this article, we review the research and developments in the acceleration of the degradation of polyolefin blends and composites, including both the fundamental science, such as the degradation mechanisms and characterizations, and application techniques, such as the processing conditions and formulations. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40750.     

Influence of functionalized polyolefin on interfacial adhesion of glass fiber‐reinforced polypropylene

Several types of functionalized polyolefins, grafted with maleic anhydride, were synthesized and used to modify the surface of fiberglass in reinforced polypropylene composites. The influence of maleated polyolefin, matrix, and compounding conditions on the interfacial bonding strength of composite were studied by measuring interfacial shear strength. The results showed that strong interactions, e.g., chemical bonding, were formed between maleated polyolefin and fiber surface. When the modified fibers were compounded with polypropylene, firm entanglements of molecular chain were formed due to the segmental interdiffusion between maleated polyolefin and matrix polypropylene. As a result, the degree of fiber‐matrix adhesion was improved. The extent of such improvement depended on the grafting degree, chain length of maleated polyolefin, and the compatibility between maleated polyolefin and matrix resin. At the same time, the compounding temperature and the cooling procedure affected the interfacial adhesion too. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1359–1365, 2000     

Synthesis, characterisation and decomposition of 1,3-benzene disulfonyl azide; a cross-linking agent for polyolefins

We have studied the thermal decomposition of 1,3-benzenedisulfonyl azide (1,3-BDSA), and verified that sulfonyl nitrenes formed are able to cross-link polyolefins, including PP. The decomposition was studied with DSC, TGA, and the GC–MS analysis of gaseous products. Both the decomposition of pure 1,3-BDSA and 1,3-BDSA dissolved in a polyolefin were studied. Decomposition occurs by loss of nitrogen giving sulfonyl nitrenes. In the polyolefin nitrenes cross-links the carbon chains by C–H insertion. Cross-linking of PP was verified with SEC. SEC showed no signs of decomposition of PP. Decomposition in the polyolefin was a first order reaction with a half-life of 25.7 s at 200 °C. Hence, 1,3-BDSA is suited for processing with polyolefins. Decomposition of pure 1,3-BDSA is more complicated with unwanted products such as SO₂ and benzene being formed, thereby emphasising the need for good blending when used in polyolefins.     

PP-g-MAH用量对废旧聚烯烃/木粉复合材料性能的影响

以木粉和废旧聚烯烃塑料为原材料制备了废旧聚烯烃/木粉复合材料,讨论了不同助剂对复合材料加工性能的影响,并进一步探讨了马来酸酐接枝聚丙烯（PP-g-MAH）用量对复合材料的加工性能、力学性能以及微观结构的影响。结果表明,在复合材料中同时添加PP-g-MAH和乙烯-醋酸乙烯脂（EVA）,其加工性能明显优于只添加EVA的复合材料;EVA用量为2 %时,PP-g-MAH用量高于9 %时,复合材料具有较低的剪切扭矩和熔融能耗;PP-g-MAH用量低于12 %时,复合材料的综合力学性能较好;而PP-g-MAH用量为9%~12%时,废旧聚烯烃形成了较为完善的连续相结构,此时复合材料的加工性能和力学性能均较好。