Beyond Mechanical Recycling: Giving New Life to Plastic Waste

Increasing the stream of recycled plastic necessitates an approach beyond the traditional recycling via melting and re‐extrusion. Various chemical recycling processes have great potential to enhance recycling rates. In this Review, a summary of the various chemical recycling routes and assessment via life‐cycle analysis is complemented by an extensive list of processes developed by companies active in chemical recycling. We show that each of the currently available processes is applicable for specific plastic waste streams. Thus, only a combination of different technologies can address the plastic waste problem. Research should focus on more realistic, more contaminated and mixed waste streams, while collection and sorting infrastructure will need to be improved, that is, by stricter regulation. This Review aims to inspire both science and innovation for the production of higher value and quality products from plastic recycling suitable for reuse or valorization to create the necessary economic and environmental push for a circular economy.     

Reducing Environmental Plastic Pollution by Designing Polymer Materials for Managed End-of-Life

Plastics are widely used synthetic materials in various industries worldwide. The abundance of plastics, which are mainly carbon-based polymers, has led to a significant accumulation of plastic waste in landfills and the environment due to their durability and affordability. Although plastic pollution of the oceans has been known for many years, there is still limited knowledge about the composition, distribution, impact, and fate of plastic waste in the environment. In this review, the focus is on environmental pollution by plastics, highlighting the source (feedstock) and degradation behavior of these materials. The goal is to provide insights for material design strategies that address the management of plastic waste at the end of its life cycle. The authors argue that the development of materials labeled marine biodegradable or universally biodegradable is not a sufficient solution on its own to address plastic pollution. Instead, it is critical to incorporate practical plans for recovery and treatment into material and product design principles. These plans should be based on existing systems or possibly developed in parallel. In summary, this article highlights the widespread pollution of the environment by plastics and emphasizes the need for comprehensive material design strategies that include not only biodegradability but also practical recovery and treatment methods. By considering the entire lifecycle of plastics, we can work to reduce the harmful impact of plastic waste on our planet.     

基于回收标志内不同数字代表塑料的单元整体教学*——以 “合成高分子”为例

以塑料回收标志内不同数字代表的塑料在生活中的用途为载体,辅助自制教具进行模型拼插,在对塑料回收标志内不同数字对应塑料的成分分析中,既落实了合成高分子的基本方法和高分子化合物在生活中的应用等学科知识,又培养了学生宏观辨识与微观探析的化学学科核心素养。     

一种新型塑料增韧剂——核壳结构聚合物

本文综述了核－壳结构聚合物用于通用塑料和工程塑料增韧的最新进展，并对该领域的研究进行了模型。     

煤与废塑料共液化中氢转移的示踪试验研究 Ⅱ．富氢塑料中的氢转移

采用放射性同位素3H标记的聚乙烯塑料进行了先锋褐煤与低密度聚乙烯（LDPE）的共液化示踪试验，并考察了钼灰（FAMo）催化剂和不同溶剂的影响，示踪试验结果表明，在先锋煤与LDPE共液化过程中，富氢塑料LDPE中的含氢基团确实起着供氢作用，而且这种含氢基团向煤液化自由基的氢转移无需经过供氢溶剂进行传递，钼灰催化剂能够加速LDPE塑料的供氢作用，使用非供氢溶剂时，在煤与LDPE共液化反应初期，LDPE中的含氢基团在钼灰催化剂作用下较易向煤热裂解产物转移，并出现供氢竞争现象。     

塑料薄膜撕扯实验在聚合物教学中的应用及讨论

结合新课标要求,揭示塑料薄膜撕扯实验在聚合物教学中的重要性、必要性。通过教学片段设计,发展学生“宏观辨识与微观探析、证据推理与模型认知”化学学科核心素养,并让学生认识物质的性能不仅取决于结构,也取决于生产工艺。并对人教版初、高中化学教材和教参中相关问题展开讨论和解释,以期更好地服务教学。     

废弃纸尿裤的处理和回收利用研究进展

随着生活水平提高和老龄化的加剧,一次性纸尿裤使用量大幅上升,目前已成为继厨房垃圾和塑料之外的第三大生活固体垃圾,因此,废弃纸尿裤的处理和回收是一个重要课题.虽然国外已有一些关于废弃纸尿裤的回收处理案例,但我国在废弃纸尿裤回收处理方面的研究报道不多.因此,本文在介绍了废弃纸尿裤处理的现状、纸尿裤的结构组成的基础上,综述了...     

Polymer Waste Valorization into Advanced Carbon Nanomaterials for Potential Energy and Environment Applications

The rise in universal population and accompanying demands have directed toward an exponential surge in the generation of polymeric waste. The estimate predicts that world-wide plastic production will rise to ≈590 million metric tons by 2050, whereas 5000 million more tires will be routinely abandoned by 2030. Handling this waste and its detrimental consequences on the Earth's ecosystem and human health presents a significant challenge. Converting the wastes into carbon-based functional materials viz. activated carbon, graphene, and nanotubes is considered the most scientific and adaptable method. Herein, this world provides an overview of the various sources of polymeric wastes, modes of build-up, impact on the environment, and management approaches. Update on advances and novel modifications made in methodologies for converting diverse types of polymeric wastes into carbon nanomaterials over the last 5 years are given. A remarkable focus is made to comprehend the applications of polymeric waste-derived carbon nanomaterials (PWDCNMs) in the CO₂ capture, removal of heavy metal ions, supercapacitor-based energy storage and water splitting with an emphasis on the correlation between PWDCNMs' properties and their performances. This review offers insights into emerging developments in the upcycling of polymeric wastes and their applications in environment and energy.     

热固性聚合物基复合材料废弃物回收利用进展

综述了目前国内外热固性聚合物基复合材料废弃物的回收利用的方法,着重论述了物理粉碎回收法和化学热解回收法,并对不同方法的回收料用于团状模压料（bulk molding compound,BMC）、片状模压料（sheet molding compound,SMC）以及热塑性塑料的产品性能进行了对比。     

晶体硅金刚线切割废料制备高纯氮化硅

以晶体硅金刚线切割废料为原料,通过氮化反应制得氮化硅,既回收了金刚线切割废料,又解决了环境污染的问题。 通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)和X射线能量色谱仪(EDS)等技术手段研究了原料经HCl和HF酸洗净化后制备氮化产物的物相组成、组分质量分数和微观形貌的影响。 结果表明,HCl酸洗后切割废料制备的氮化产物中主要物相为Si₂N₂O和Si₃N₄,而HF酸洗后切割废料制备的氮化产物中主要物相为Si₃N₄。 氮化产物中Si₂N₂O的形成与切割废料中SiO₂的质量分数有关,降低原料中SiO₂的质量分数是切割废料经过高温氮化制得氮化硅的前提。     

Efficient Recycling of Gold and Copper from Electronic Waste by Selective Precipitation

The recycling of metals from electronic waste (e-waste) using efficient, selective, and sustainable processes is integral to circular economy and net-zero aspirations. Herein, we report a new method for the selective precipitation of metals such as gold and copper that offsets the use of organic solvents that are traditionally employed in solvent extraction processes. We show that gold can be selectively precipitated from a mixture of metals in hydrochloric acid solution using triphenylphosphine oxide (TPPO), as the complex [(TPPO)₄(H₅O₂)][AuCl₄]. By tuning the acid concentration, controlled precipitation of gold, zinc and iron can be achieved. We also show that copper can be selectively precipitated using 2,3-pyrazinedicarboxylic acid (2,3-PDCA), as the complex [Cu(2,3-PDCA-H)₂]_n ⋅ 2n(H₂O). The combination of these two precipitation methods resulted in the recovery of 99.5 % of the Au and 98.5 % of the Cu present in the connector pins of an end-of-life computer processing unit. The selectivity of these precipitation processes, combined with their straightforward operation and the ability to recycle and reuse the precipitants, suggests potential industrial uses in the purification of gold and copper from e-waste.     

Conversion of Polypropylene Waste into Value-Added Products: A Greener Approach

Plastic has made our lives comfortable as a result of its widespread use in today’s world due to its low cost, longevity, adaptability, light weight and hardness; however, at the same time, it has made our lives miserable due to its non-biodegradable nature, which has resulted in environmental pollution. Therefore, the focus of this research work was on an environmentally friendly process. This research work investigated the decomposition of polypropylene waste using florisil as the catalyst in a salt bath over a temperature range of 350–430 °C. A maximum oil yield of 57.41% was recovered at 410 °C and a 40 min reaction time. The oil collected from the decomposition of polypropylene waste was examined using gas chromatography-mass spectrometry (GC-MS). The kinetic parameters of the reaction process were calculated from thermogravimetric data at temperature program rates of 3, 12, 20 and 30 °C·min⁻¹ using the Ozawa–Flynn–Wall (OFW) and Kissinger–Akahira–Sunnose (KAS) equations. The activation energy (Ea) and pre-exponential factor (A) for the thermo-catalytic degradation of polypropylene waste were observed in the range of 102.74–173.08 kJ·mol⁻¹ and 7.1 × 10⁸–9.3 × 10¹¹ min⁻¹ for the OFW method and 99.77–166.28 kJ·mol⁻¹ and 1.1 × 10⁸–5.3 × 10¹¹ min⁻¹ for the KAS method at a percent conversion (α) of 0.1 to 0.9, respectively. Moreover, the fuel properties of the oil were assessed and matched with the ASTM values of diesel, gasoline and kerosene oil. The oil was found to have a close resemblance to the commercial fuel. Therefore, it was concluded that utilizing florisil as the catalyst for the decomposition of waste polypropylene not only lowered the activation energy of the pyrolysis reaction but also upgraded the quantity and quality of the oil.     

Applying the Principles of Green Chemistry to Polymer Production Technology

The 12 principles of green chemistry are reviewed and applied specifically to polymer production. Examples of how the principles relate to current practice in polymer reaction engineering and which areas show the greatest potential impact for implementation of these principles are discussed. This paper does not attempt to be exhaustive but rather to target specific areas for further development.     

金属-有机骨架材料用于废水处理

废水中的各种有害物质常常具有生物毒性或致癌性,因此如何高效、节能地处理水体污染是一个亟待解决的重要问题。金属-有机骨架材料(metal-organic frameworks, MOFs)是一种新型纳米多孔材料,具有种类多样性、结构可设计性与可调控性、高比表面积及良好的热稳定性等优点,已成为当前化学、材料学科的一个研究热点, 在多个领域显示出潜在的应用前景,尤其是在分离方面。与气相分离相比,MOFs用于液相分离的研究较少。本文综述了近年来MOFs用于含有染料、药物、醇、芳香族化合物、重金属离子及其他离子的废水处理的研究进展,重点剖析了MOFs的孔结构、骨架电荷及功能性对分离效果的影响,并结合本课题组的研究工作,对这种新型多功能材料在水处理方面的前景和今后的研究重点作了展望。     

Novel Efficient Acidic Ionic Liquid Polymer for Biodiesel Synthesis from Waste Oils

Kinetics and Catalysis - A highly stable acid ionic liquid polymer was prepared via the polymerization of 1-vinyl-3-(propyl-3-sulfony) imidazolium 4-styrenesulfonate. Both the cations and anions...     

Upgrading Solid Digestate from Anaerobic Digestion of Agricultural Waste as Performance Enhancer for Starch-Based Mulching Biofilm

Developing a green and sustainable method to upgrade biogas wastes into high value-added products is attracting more and more public attention. The application of solid residues as a performance enhancer in the manufacture of biofilms is a prospective way to replace conventional plastic based on fossil fuel. In this work, solid digestates from the anaerobic digestion of agricultural wastes, such as straw, cattle and chicken manures, were pretreated by an ultrasonic thermo-alkaline treatment to remove the nonfunctional compositions and then incorporated in plasticized starch paste to prepare mulching biofilms by the solution casting method. The results indicated that solid digestate particles dispersed homogenously in the starch matrix and gradually aggregated under the action of a hydrogen bond, leading to a transformation of the composites to a high crystalline structure. Consequently, the composite biofilm showed a higher tensile strength, elastic modulus, glass transition temperature and degradation temperature compared to the pure starch-based film. The light, water and GHG (greenhouse gas) barrier properties of the biofilm were also reinforced by the addition of solid digestates, performing well in sustaining the soil quality and minimizing N₂O or CH₄ emissions. As such, recycling solid digestates into a biodegradable plastic substitute not only creates a new business opportunity by producing high-performance biofilms but also reduces the environmental risk caused by biogas waste and plastics pollution.     

Fluorescence Detection of Atenolol Using a Molecular Imprinted Polymer

Abstract

A molecular imprinted polymer (MIP) for the recognition of atenolol has been synthesized using a non‐covalent approach. Finally, this MIP has been utilized as a recognition element in a flow‐through optosensing system with fluorescence detection, showing desirable sensitivity and selectivity characteristics.     

Stable Efficient Dye-Sensitized Solar Cell Using Waste Polyvinyl Chloride (PVC) Derived Porous Carbon as Counter Electrode

At the time, the world critically requires renewable energy. The challenge is figuring out how to meet expanding global energy consumption. Dye-sensitized solar cells (DSCs) have attracted a lot of interest due to their high energy conversion efficiency, low cost, environmental friendliness, and easy production procedure. First, the study prepares standard cell platinum, which is the most expensive and in low supply. By replacing PVC-derived porous carbon for expensive platinum in the DSScs counter electrode. The standard efficiency of platinum counter electrode comes out to be 1.94 and efficiency of PVC derived porous carbon electrode comes out to be 0.46.     

Thermal Catalytic-Cracking Low-Density Polyethylene Waste by Metakaolin-Based Geopolymer NaA Microsphere

Metakaolin-based geopolymer microspheres (MGM) with hierarchical pore structures were prepared by suspension dispersion method in dimethicone at 80 °C. The hydrothermal modification of MGM was carried out at a lower temperature of 80 °C, and a NaA molecular sieve converted from metakaolin-based geopolymer (NMGM) with good crystal structure was prepared and applied in thermal catalytic cracking of low-density polyethylene (LDPE) reaction. The one-pot two-stage thermal catalytic cracking of LDPE was carried out in a 100 mL micro-autoclave under normal pressure. In this work, the optimal proportions and optimal reaction conditions of catalysts for NMGM thermal catalytic cracking of LDPE waste to fuel oil were investigated. The NMGM catalyst showed high selectivity to the liquid product of thermal catalytic cracking of waste LDPE. Under the reaction conditions of reaction time of 1 h and reaction temperature of 400 °C, the liquid-phase yield of thermal catalytic cracking of LDPE reached a high of 88.45%, of which the content of gasoline components was 10.14% and the content of diesel components was 80.97%.