Article
Polymer Science
Victor S. Cecon, Paulo F. Da Silva, Keith L. Vorst, Greg W. Curtzwiler
Summary: Polyethylene recycling is gaining momentum, with research showing that blending polyethylene of different densities with recycled polyethylene can optimize product performance and reduce costs.
POLYMER DEGRADATION AND STABILITY
(2021)
Article
Polymer Science
Erdal Karaagac, Mitchell P. Jones, Thomas Koch, Vasiliki-Maria Archodoulaki
Summary: Plastic recycling aims to balance functionality and mass producibility with environmental sustainability, but faces challenges with contamination and heterogeneous properties in recycled materials. This study investigated polypropylene (PP) contamination in post-consumer low-density polyethylene (PE-LD) and mixed polyolefin (PO) regranulates, finding that PP content affects mechanical properties and can be better estimated using FT-IR band ratios. Compatibilisation with ethylene-based olefin block copolymer showed promise in improving properties of recycled materials for higher quality regranulates.
Article
Chemistry, Multidisciplinary
Connor J. Stubbs, Joshua C. Worch, Hannah Prydderch, Zilu Wang, Robert T. Mathers, Andrey Dobrynin, Matthew L. Becker, Andrew P. Dove
Summary: Stereochemistry in polymers plays a significant role in controlling the mechanical and physical properties of materials. This study demonstrates that stereochemical differences in sugar-based monomers can result in a family of nonsegmented, alternating polyurethanes with exceptional properties. The behavior of these polymers is defined by distinct intra- and interchain supramolecular hydrogen-bonding interactions. The chemical similarity among these polymers allows for independent control over degradability and mechanical properties through statistical copolymerization and blending.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Engineering, Environmental
Caterina Picuno, Ayah Alassali, Zhi Kai Chong, Kerstin Kuchta
Summary: This study provides a comprehensive investigation on the current state of the German post-consumer plastic packaging sector, revealing the intrinsic inefficiencies in the waste value chain. The research findings show that the per capita generation of PCPP waste in Germany is 26.3 kg, with a separate collection efficiency of 74.8%. The study highlights that material losses at the sorting stage are mainly due to complex packaging designs.
RESOURCES CONSERVATION AND RECYCLING
(2021)
Article
Polymer Science
Mohamad Hassan Akhras, Paul J. Freudenthaler, Klaus Straka, Joerg Fischer
Summary: This study presents an open-loop recycling process for a specific type of plastic waste. Two methods of waste collection, informal and formal, were used to obtain high-density polyethylene beverage bottle caps. The materials were then sorted, shredded, regranulated, and injection-molded into a frisbee. Various tests were conducted to observe changes in the material throughout the recycling process. The study found that informal collection produced a purer input stream and resulted in lower melt mass-flow rate. The presence of polypropylene cross-contamination affected the properties of the materials.
Article
Polymer Science
Erdal Karaagac, Thomas Koch, Vasiliki-Maria Archodoulaki
Summary: The study found that the ethylene-based olefin block copolymer was the most effective compatibilizer, able to encapsulate dispersed vPP particles in a vHDPE matrix (core-shell morphology) and exhibit the best adhesion to polymer blend components.
Article
Green & Sustainable Science & Technology
Lily D. Poulikakos, Emiliano Pasquini, Marjan Tusar, David Hernando, Di Wang, Peter Mikhailenko, Marco Pasetto, Andrea Baliello, Augusto Cannone Falchetto, Miomir Miljkovic, Marko Oreskovic, Nunzio Viscione, Nikhil Saboo, Gabriel Orozco, Eric Lachance-Tremblay, Michel Vaillancourt, Muhammad Rafiq Kakar, Nicolas Bueche, Jan Stoop, Lacy Wouters, Davide Dalmazzo, Gustavo Pinheiro, Kamilla Vasconcelos, Fernando Moreno Navarro
Summary: This research investigated the performance of asphalt mixtures modified with polyethylene (PE) waste. The results showed that the PE modified mixtures had better compactability, higher stiffness, lower creep rate, and improved resistance to permanent deformation compared to the control mixtures. The wheel tracking tests also indicated similar or better results when 1.5% PE was added to the control mixture. The findings suggest that using PE as a performance-enhancing additive in asphalt pavements is a viable and environmentally friendly option.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Manufacturing
Eggo Ulphard Thoden van Velzen, Sharon Chu, Fresia Alvarado Chacon, Marieke T. Brouwer, Karin Molenveld
Summary: The mechanical properties of rPE are affected by the composition of the feedstock, with rPE made from single-grade bottle bodies exhibiting the highest impact resistance. The addition of bodies made from other types of PE decreases impact resistance but increases elongation at break. The best analysis method to determine the polymeric composition of rPE and predict its mechanical properties is near-infrared-assisted flake analysis.
PACKAGING TECHNOLOGY AND SCIENCE
(2021)
Article
Polymer Science
Roberta Capuano, Irene Bonadies, Rachele Castaldo, Mariacristina Cocca, Gennaro Gentile, Antonio Protopapa, Roberto Avolio, Maria Emanuela Errico
Summary: This paper presents a sustainable strategy for valorizing and recycling heterogeneous polymer-based post-consumer waste using high-energy mechano-chemical treatment. The treated material showed improved deformability and mechanical parameters, with the addition of small amounts of organic peroxide leading to further enhancements in morphology and performance.
Article
Polymer Science
Jerzy Korol, Aleksander Hejna, Klaudiusz Wypior, Krzysztof Mijalski, Ewelina Chmielnicka
Summary: Plastic recycling is a significant industrial challenge, but by adding compatibilizers, the performance of waste materials can be improved, increasing their utility and potential for reuse.
Article
Construction & Building Technology
Miguel Martinez-Lopez, Gonzalo Martinez-Barrera, Rene Salgado-Delgado, Osman Gencel
Summary: The study investigated the impact of waste polypropylene and waste polyethylene on mechanical characteristics of polymer mortars, finding that adding waste can improve some mechanical properties, but also decrease flexural strength and elasticity modulus.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Tanyaradzwa S. Muzata, Laurent M. Matuana, Muhammad Rabnawaz
Summary: This article investigates the compatibilization of mixed polyolefins containing municipal solid waste (MSW) using different types of compatibilizers. The study finds that a commercial styrenic block copolymer offers superior performance, enabling the synthesis of virgin-like high-density polyethylene (HDPE) from the mixed polyolefins.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Polymer Science
Markus Gall, Paul J. Freudenthaler, Joerg Fischer, Reinhold W. Lang
Summary: Efforts towards a circular plastics economy are putting pressure on recycled plastics, especially recycled polyethylene and recycled polypropylene, to enter new markets. A detailed understanding of composition and structure-property relationships of post-consumer recyclates needs to be developed to meet the demands of more circularity.
Article
Polymer Science
Ines Traxler, Stephan Laske, Joerg Fischer
Summary: Thermoformed products have potential for using recycled materials in multilayer structures. In this study, four commercially available polypropylene recyclates were tested as core layers for thermoformed products with top layers of virgin polypropylene. The recyclates showed lower stiffness but higher toughness due to polyethylene contamination, and cups made with recyclate material had lower shrinkage and top load. Three strategies for improving product performance were tested, all of which achieved better results in terms of shrinkage behavior and top load.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Polymer Science
Louise Pick, Paul R. Hanna, Luke Gorman
Summary: This paper presents a study on the use of post-consumer waste polymer in the rotational moulding process. The materials showed high viscosities at low shear rates, which affected the melt flow and bubble removal during the process. The moulded materials had poor surface finishes and lower impact and tensile strength compared to virgin material.
JOURNAL OF POLYMER ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
R. Steinlechner, R. de Oro Calderon, T. Koch, P. Linhardt, W. D. Schubert
Summary: The manuscript systematically studied three groups of Ni-based cemented carbides compared to a standard Co-based system, highlighting higher solubility of alloying elements in Ni binder, the effect of carbon content on alloying, and superior corrosion resistance of high-alloyed NiCr and NiCrMo materials.
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
(2022)
Article
Polymer Science
Raffael Wolff, Katharina Ehrmann, Patrick Knaack, Konstanze Seidler, Christian Gorsche, Thomas Koch, Juergen Stampfl, Robert Liska
Summary: This study reports the direct 3D printing of phenoplasts using Hot Lithography, a stereolithography-based 3D printing technology at elevated temperatures. Bubble-free specimens were obtained by suitable formulations and post-curing, enabling simple production of complicated structures.
Article
Polymer Science
Johannes Steindl, Katharina Ehrmann, Christian Gorsche, Ching-Chung Huang, Thomas Koch, Patrick Steinbauer, Andreas Rohatschek, Orestis G. Andriotis, Philipp J. Thurner, Alexander Prado-Roller, Juergen Stampfl, Robert Liska
Summary: The transfer of ABS microstructure to photopolymers via a designed monomer system has been achieved, resulting in new materials with high toughness.
POLYMER INTERNATIONAL
(2022)
Article
Polymer Science
Markus Kury, Katharina Ehrmann, Christian Gorsche, Peter Dorfinger, Thomas Koch, Jurgen Stampfl, Robert Liska
Summary: By adjusting the radical curing mechanism using difunctional vinyl sulfonate esters, the final material properties of acrylate networks can be modified to obtain toughened 3D structured materials. The resulting materials show improved thermomechanical behavior compared to those regulated by state-of-the-art reagents such as thiols, with reduced shrinkage stress, warpage, higher conversion, and glass transition temperature.
POLYMER INTERNATIONAL
(2022)
Article
Polymer Science
Yazgan Mete, Konstanze Seidler, Christian Gorsche, Thomas Koch, Patrick Knaack, Robert Liska
Summary: This study presents a novel approach to 3D print polyesters directly from ε-caprolactone via stereolithography at elevated temperatures. The introduction of low amounts of crosslinkers improves the stability of the structure while maintaining its degradability and semicrystallinity. The study also highlights the significant influence of the amount and type of crosslinker on the material properties.
POLYMER INTERNATIONAL
(2022)
Article
Materials Science, Characterization & Testing
Emanuel Boschmeier, Vasiliki-Maria Archodoulaki, Andreas Schwaighofer, Bernhard Lendl, Andreas Bartl
Summary: A faster, more reliable and eco-friendly tool to detect and quantify elastane in textiles using DSC was developed in this study. The EQT showed promising results in determining elastane contents quickly and accurately. It has the potential to become widely used in the textile production chain, especially in the upcoming recycling sector.
Article
Engineering, Chemical
Nina Wolfsgruber, Andreas Tanda, Vasiliki-Maria Archodoulaki, Christoph Burgstaller
Summary: This study investigates the influence of different fillers and matrices on the thermal conductivity of polymer matrix composites. Various inorganic fillers and thermoplastic matrices were used to produce thermally conductive polymer matrix composites. The results show that the combination of particle shape and intrinsic thermal conductivity of the filler has the greatest impact on the thermal conductivity of the composite.
POLYMER ENGINEERING AND SCIENCE
(2023)
Article
Engineering, Environmental
Harsha Raghuram, Julia Roitner, Mitchell P. Jones, Vasiliki-Maria Archodoulaki
Summary: The use of recycled polymers is limited by mechanical-property-dependant requirements, resulting in downcycling into low-value products. Exploring new applications and upcycling requires careful design and understanding of application-specific requirements and differences between polymer grades. Assessing the higher-value system-specific opportunities of reprocessed PE-HDs in the field of tribology, it was found that reprocessed PE-HD exhibits differences in melt flow and mechanical properties compared to virgin PE-HD, but is comparable to PE-UHMW in tribological system-specific requirements. The use of reprocessed PE-HD in this field constitutes upcycling and is critical for meeting ambitious EU targets and legislation on recycled material use.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Review
Environmental Sciences
Gilbert Moyen Massa, Vasiliki-Maria Archodoulaki
Summary: The lack of proper waste management in developing countries leads to environmental pollution and human illness. This review examines the generation and transportation of electronic and electrical waste in Africa. Attention is given to waste treatment, recycling, and methods for recovering metals from e-waste. The roles and responsibilities of stakeholders and institutions in Africa are discussed. Design for Environment guidelines and Sustainable Product Design Concepts are used to find strategies for managing e-waste, specifically in Africa. Raising awareness among national and international institutions is crucial to improve e-scrap management in Africa. Measures should be taken to facilitate the transition of e-waste management from the informal to formal sector, creating decent jobs and incomes.
Article
Engineering, Environmental
Sophia Mihalyi, Michelle Tagliavento, Emanuel Boschmeier, Vasiliki-Maria Archodoulaki, Andreas Bartl, Felice Quartinello, Georg M. Guebitz
Summary: In this study, enzymes were used to decompose cellulose from blended fibers, recovering synthetic fibers and converting glucose into lactic acid for biobased polyester production. Simultaneous saccharification and fermentation by Weizmannia coagulans were investigated to reduce enzyme inhibition and process costs. Viscose fibers in blends were completely hydrolyzed, while pure synthetic fibers were recovered, demonstrating a circular economy concept for recycling and valorizing blended textile waste.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Engineering, Environmental
Emanuel Boschmeier, Vasiliki-Maria Archodoulaki, Andreas Schwaighofer, Bernhard Lendl, Wolfgang Ipsmiller, Andreas Bartl
Summary: In this study, a feasible and up-scalable elastane separation process based on a non-hazardous selective solvent was developed successfully. The non-hazardous solvent dimethyl sulfoxide (DMSO) was identified as the most favorable solvent, and the developed process was validated through spectroscopic measurements, differential scanning calorimetry, and scanning electron microscopy.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Polymer Science
Martina Seier, Vasiliki-Maria Archodoulaki, Thomas Koch, Bernadette Duscher, Markus Gahleitner
Summary: Food preservation is a crucial application of polymers in packaging, with multilayer films being commonly used to extend the shelf life of sensitive foods. However, the recyclability of these films is limited. This study evaluated and compared the recycling potential of PET and PP post-consumer modified atmosphere packaging (MAP) through structure analysis and recycling simulation, finding that the PET-based packaging resulted in a brittle material unsuitable for reprocessing, while the PP-based packaging showed potential for closed-loop recycling.
Article
Chemistry, Physical
Raffael Wolff, Patrick Knaack, Konstanze Seidler, Christian Gorsche, Thomas Koch, Juergen Stampfl, Robert Liska
Summary: Polycyanurates have excellent thermomechanical properties due to their unique triazine structure and phenolic chains. A new method of additive manufacturing using photo-induced catalytic poly-trimerization and Hot Lithography allows for the production of pure polycyanurates without relying on matrix polymers or fillers. The 3D printed structures exhibit thermomechanical values that have rarely been attainable before, making this process a promising opportunity for high-performance polymer production in additive manufacturing.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Engineering, Environmental
Jessica Schlossnikl, Elisabeth Pinter, Mitchell P. Jones, Thomas Koch, Vasiliki- Maria Archodoulaki
Summary: This article investigates the properties of polypropylene labels during mechanical recycling and highlights the challenges that may arise during the recycling process. The presence of labels influences the performance of the blends, and the labels contain substances associated with DNA-reactive mutagenicity. Although the labels are recyclable, their complex processing requirements, safety concerns, and limited economic feasibility pose challenges.
RESOURCES CONSERVATION AND RECYCLING
(2024)
Article
Green & Sustainable Science & Technology
Harsha Raghuram, Martina Seier, Thomas Koch, Mitchell P. Jones, Vasiliki- Maria Archodoulaki
Summary: Polypropylene, one of the most commonly used polymers, is rarely used for technical applications in recycling. Reprocessing-induced changes in mechanical and melt properties restrict its application scope. However, reprocessing has the opposite effect on the tribological properties of polypropylene, reducing wear by changing the supramolecular structure.
SUSTAINABLE MATERIALS AND TECHNOLOGIES
(2023)
Article
Engineering, Environmental
Xiaojian Liu, Bei Wang, Yayun Ma, Xiangyang Zhou, Juan Yang, Yuehui He, Jingjing Tang, Fanyun Su, Wan Yang
Summary: This study proposes a combined process of reduction roasting of herb-medicine residue and oxalic acid leaching to improve the recovery efficiency of lithium from spent lithium-ion batteries. By utilizing the reducing gas produced from the pyrolysis of herb-medicine residue, the layered structure of the cathode powder is destroyed and converted into Li2CO3, Ni, Co, and MnO. Additionally, selective extraction of lithium is achieved using oxalic acid, and the efficiency and kinetics of lithium extraction are improved under the combined action of herb-medicine residue and oxalic acid.
Article
Engineering, Environmental
Muxina Konarova, Nuno Batalha, Gabriel Fraga, Mohamed H. M. Ahmed, Steven Pratt, Bronwyn Laycock
Summary: This study presents a proof of concept for a technology that integrates PET recovery from mixed plastic waste and plastic pyrolysis. By depolymerizing PET into TPA using a low volatility oil as medium, it achieves low-pressure operation and a selective separation and recovery of TPA from the product mix. Full PET conversion and high TPA recovery were achieved, making it an effective solution for processing mixed waste streams and improving the yield and quality of liquid product from thermal pyrolysis compared to untreated feedstock.
Article
Engineering, Environmental
Zhenhua Sun, Jing Li, Xuejiang Wang, Siqing Xia, Jianfu Zhao
Summary: This study investigated the influence of in-situ formed MgFe2O4 on the hydrothermal treatment of swine manure. The results showed that the in-situ formation of MgFe2O4 improved the dehydration and decarboxylation of organic components in swine manure, thereby improving its carbonization degree. Furthermore, it enhanced the stabilization of heavy metals and the retention of phosphorus. MgFe2O4 modified hydrochars exhibited remarkable adsorption capacity for Pb(II) and Cu(II) without any leaching of heavy metals.
Article
Engineering, Environmental
Yijing Jiang, Boyang Leng, Jingxin Xi
Summary: The increased generation of municipal solid waste has had a significant impact on the economy, environment, and public health. The current waste treatment process has limitations. By developing a comprehensive social costing model, this study assesses the impacts of municipal solid waste management throughout its life cycle and provides policymakers with best practices and feasibility information.
Article
Engineering, Environmental
Marina Hernandes de Paula e Silva, Ricardo Coser Mergulha, Jose Geraldo Vidal Vieira, Andrea Brasco Pampanelli, Rodrigo Salvador, Diogo Aparecido Lopes Silva
Summary: This study developed and implemented a self-assessment tool to assist companies in decision-making processes for establishing circular flows based on Lean Manufacturing and Circular Economy principles. The tool utilized a maturity model and was applied to nine companies of varying characteristics. The findings revealed that certain companies showed higher maturity in water-waste and chemical-emissions management, with larger enterprises focusing on these strategies. However, many companies lacked sufficient training and employee awareness prior to seeking cleaner alternatives, and comprehensive actions to manage the product lifecycle were lacking. To address these gaps, the tool provided tailored recommendations for each company to improve their processes, products, and value chain.
Article
Engineering, Environmental
Gamze Dogdu, Turgay Pekdemir, Sanaz Lakestani, Seyda Karabork, Osman Cavus
Summary: This paper presents data on food waste associated with mini size food packaging services, highlighting the difficulties in emptying the food and consumer wastefulness as the main causes. These findings have significant implications for the sustainability of food and relevant packaging.
Article
Engineering, Environmental
Qingxia Li, Xin Kong, Yuxin Chen, Jianan Niu, Jia Jing, Jin Yuan, Yifeng Zhang
Summary: This study investigates how to enhance methane production from food waste after hydrothermal pretreatment. The results demonstrate a significant increase in methane yield when zero-valent iron and magnetite are used together, and high organic loading is favorable for methane production. Microbial diversity analysis further reveals the dominant pathways and metabolic processes involved in methane generation.
Article
Engineering, Environmental
D. H. H. Sim, I. A. W. Tan, L. L. P. Lim, E. T. Lau, B. H. Hameed
Summary: The development of controlled-release fertilizer formulation is important for preventing environmental pollution caused by nutrient leaching and volatilization. This study combined biochar-based fertilizer with encapsulation technology to improve the nutrient release mechanism. Optimal conditions for synthesizing urea-impregnated biochar (UIB) were determined using central composite design, and the release of nitrogen was described by mathematical models. Results showed that encapsulated UIB (EUIB) achieved complete release of nitrogen in water and exhibited improved water retention in sandy-textural soil. Therefore, EUIB derived from peppercorn waste has the potential to be used as a sustainable controlled-release fertilizer for agriculture.
Article
Engineering, Environmental
Yuchuan Wang, Neslihan Akdeniz
Summary: Incorporating biochar into composting systems can increase compost temperatures. This study developed a heat transfer model for a biochar-amended co-composting system and found that biochar increased thermal conductive losses but also enhanced microbial activity, resulting in an overall increase in total heat unit. When biochar was applied on the surface, it mainly functioned as an insulator.
Article
Engineering, Environmental
George Tsalis, Birger Boutrup Jensen, Jessica Aschemann-Witzel
Summary: This paper empirically explores the relationship between retail price promotions and household food waste. The results show that households with a higher proportion of discount food purchases and environmental awareness tend to waste less food, while larger households and those lacking food handling skills tend to waste more food.
Article
Engineering, Environmental
Lukas Friederici, Arne Koch, Patrick Martens, Jana Pantzke, Sebastiano Di Bucchianico, Thorsten Streibel, Christopher P. Rueger, Ralf Zimmermann
Summary: The increasing demand for lightweight materials has led to a rise in fiber-reinforced plastic (FRP) production. However, the properties and compositional range of FRPs pose challenges to recycling strategies. Pyrolysis has emerged as a promising method for separating the fibers from the polymer matrix. This study investigated the pyrolysis process using thermal analysis and high-resolution mass spectrometry, and also assessed the toxicity of the recovered fibers using an in vitro model.
Review
Engineering, Environmental
Devika Kannan, Shakiba Khademolqorani, Nassibeh Janatyan, Somaieh Alavi
Summary: This paper introduces Smart Waste Management (SWM) that applies Industry 4.0 technologies in waste management. A framework called SWM4.0 is developed, which highlights the importance of smart people, smart cities, smart enterprises, and smart factories in achieving successful waste management. The paper also suggests future research directions and managerial implications.