1
|
Gall M, Mileva D, Stockreiter W, Salles C, Gahleitner M. Comparing End-of-Life Vehicle (ELV) and Packaging-Based Recyclates as Components in Polypropylene-Based Compounds for Automotive Applications. Polymers (Basel) 2024; 16:1927. [PMID: 39000782 PMCID: PMC11243903 DOI: 10.3390/polym16131927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Revised: 07/01/2024] [Accepted: 07/04/2024] [Indexed: 07/17/2024] Open
Abstract
Increasing recycled plastic content in cars to 25% by 2030 is one of the key measures for decarbonizing the automotive industry defined by the European Commission. This should include the recovery of plastics from end-of-life vehicles (ELVs), but such materials are hardly used in compounds today. To close the knowledge gap, two ELV recyclate grades largely based on bumper recycling were analyzed in comparison to a packaging-based post-consumer recyclate (PCR). The composition data were used to design polypropylene (PP) compounds for automotive applications with virgin base material and mineral reinforcement, which were characterized in relation to a commercial virgin-based compound. A compound with a 40 wt.-% ELV-based bumper recyclate can exceed one with just a 25 wt.-% packaging-based recyclate in terms of stiffness/impact balance. While the virgin reference can nearly be matched regarding mechanics, the flowability is not reached by any of the PCR compounds, making further development work necessary.
Collapse
Affiliation(s)
- Markus Gall
- Borealis Polyolefine GmbH, Innovation Headquarters, St Peterstr. 25, 4021 Linz, Austria
| | - Daniela Mileva
- Borealis Polyolefine GmbH, Innovation Headquarters, St Peterstr. 25, 4021 Linz, Austria
| | - Wolfgang Stockreiter
- Borealis Polyolefine GmbH, Innovation Headquarters, St Peterstr. 25, 4021 Linz, Austria
| | | | - Markus Gahleitner
- Borealis Polyolefine GmbH, Innovation Headquarters, St Peterstr. 25, 4021 Linz, Austria
| |
Collapse
|
2
|
Hao P, Siebers C, Ragaert K, Gilabert FA. Advancing the Characterization of Recycled Polyolefin Blends with a Combined Experimental and Numerical Approach to Thermomechanical Behavior. Polymers (Basel) 2024; 16:1153. [PMID: 38675072 PMCID: PMC11054691 DOI: 10.3390/polym16081153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 04/11/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
The blending of polyolefins (POs), such as polyethylene (PE) and polypropylene (PP), is a growing area of research, particularly for recycling mixed polyolefin (MPO) waste through flotation sorting techniques. However, understanding the thermomechanical behavior of these recycled blends is challenging due to limitations in the existing characterization methods. This paper introduces a combined experimental and numerical method to accurately assess the complex mechanical behavior of high-density PE, PP, and their blends. We conducted detailed thermomechanical analyses using a high-speed stereo digital image correlation (DIC) system paired with an infrared camera to capture temperature variations alongside mechanical stress and strain. This approach allowed us to correct for distortions caused by necking and to derive accurate stress-strain relationships. We also applied a cutting-edge unified semi-crystalline polymer (USCP) model to simplify the analysis, focusing on the effects of strain rate and temperature, including self-heating and thermal softening phenomena. Our results, which closely match experimental observations of stress-strain behavior and temperature changes, offer new insights into the thermomechanical properties of PO blends, which are essential for advancing their practical applications in various fields.
Collapse
Affiliation(s)
- Pei Hao
- Department of Materials, Textiles and Chemical Engineering (MaTCh), Mechanics of Materials and Structures (MMS), Tech Lane Ghent Science Park-Campus A, Ghent University (UGent), Technologiepark-Zwijnaarde 46, 9052 Ghent, Belgium;
| | - Charmayne Siebers
- Circular Plastics, Department of Circular Chemical Engineering, Faculty of Science and Engineering, Maastricht University, Urmonderbaan 22, 6167 RD Geleen, The Netherlands; (C.S.); (K.R.)
| | - Kim Ragaert
- Circular Plastics, Department of Circular Chemical Engineering, Faculty of Science and Engineering, Maastricht University, Urmonderbaan 22, 6167 RD Geleen, The Netherlands; (C.S.); (K.R.)
| | - Francisco A. Gilabert
- Department of Materials, Textiles and Chemical Engineering (MaTCh), Mechanics of Materials and Structures (MMS), Tech Lane Ghent Science Park-Campus A, Ghent University (UGent), Technologiepark-Zwijnaarde 46, 9052 Ghent, Belgium;
| |
Collapse
|
3
|
Zheng L, Wang M, Li Y, Xiong Y, Wu C. Recycling and Degradation of Polyamides. Molecules 2024; 29:1742. [PMID: 38675560 PMCID: PMC11052090 DOI: 10.3390/molecules29081742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 03/31/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
As one of the five major engineering plastics, polyamide brings many benefits to humans in the fields of transportation, clothing, entertainment, health, and more. However, as the production of polyamide increases year by year, the pollution problems it causes are becoming increasingly severe. This article reviews the current recycling and treatment processes of polyamide, such as chemical, mechanical, and energy recovery, and degradation methods such as thermal oxidation, photooxidation, enzyme degradation, etc. Starting from the synthesis mechanism of polyamide, it discusses the advantages and disadvantages of different treatment methods of polyamide to obtain more environmentally friendly and economical treatment schemes. Finding enzymes that can degrade high-molecular-weight polyamides, exploring the recovery of polyamides under mild conditions, synthesizing environmentally degradable polyamides through copolymerization or molecular design, and finally preparing degradable bio-based polyamides may be the destination of polyamide.
Collapse
Affiliation(s)
- Lin Zheng
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
| | - Mengjin Wang
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
| | - Yaoqin Li
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
| | - Yan Xiong
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
- Hubei Longzhong Laboratory, Xiangyang 441000, China
| | - Chonggang Wu
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Collaborative Innovation Center of Green Light-Weight Materials and Processing, New Materials and Green Manufacturing Talent Introduction and Innovation Demonstration Base, School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; (L.Z.); (M.W.); (Y.L.); (Y.X.)
- Hubei Longzhong Laboratory, Xiangyang 441000, China
| |
Collapse
|
4
|
Guo J, Luo C, Wittkowski C, Fehr I, Chong Z, Kitzberger M, Alassali A, Zhao X, Leineweber R, Feng Y, Kuchta K. Screening the Impact of Surfactants and Reaction Conditions on the De-Inkability of Different Printing Ink Systems for Plastic Packaging. Polymers (Basel) 2023; 15:2220. [PMID: 37177366 PMCID: PMC10180929 DOI: 10.3390/polym15092220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/27/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
One of the major applications (40% in Europe) of plastic is packaging, which is often printed to display required information and to deliver an attractive aesthetic for marketing purposes. However, printing ink can cause contamination in the mechanical recycling process. To mitigate this issue, the use of surfactants in an alkaline washing process, known as de-inking, has been employed to remove printing ink and improve the quality of recyclates. Despite the existence of this technology, there are currently no data linking the de-inking efficiency with typical printing ink compositions. Additionally, it is necessary to investigate the de-inking process under the process parameters of existing recycling plants, including temperature, NaOH concentration, and retention time. This study aims to evaluate the performance of commonly used printing inks with different compositions under various washing scenarios for plastic recycling in conjunction with different de-inking detergents containing surfactants or mixtures of surfactants. The results indicate that the pigments applied to the ink have no significant effect on the de-inking process, except for carbon black (PBk 7). Nitrocellulose (NC) binder systems exhibit high de-inkability (over 95%) under the condition of 55 °C and 1 wt.% NaOH. However, crosslinked binder systems can impede the de-inking effect, whether used as a binder system or as an overprint varnish (OPV). The de-inking process requires heating to 55 °C with 1 wt.% NaOH to achieve a substantial effect. Based on the findings in this work, breaking the Van der Waals forces, hydrogen bonds, and covalent bonds between the printing ink and plastic film is an essential step to achieve the de-inking effect. Further research is needed to understand the interaction between surfactants and printing inks, enabling the development of de-inkable printing inks and high-performance surfactants that allow for de-inking with less energy consumption. The surfactant and NaOH have a synergistic effect in cleaning the printing ink. NaOH provides a negative surface charge for the adsorption of the cationic head of the surfactant and can hydrolyze the covalent bonds at higher concentrations (>2 wt.%).
Collapse
Affiliation(s)
- Jinyang Guo
- Circular Resource Engineering and Management (CREM), Hamburg University of Technology (TUHH), Blohm Str. 15, 21079 Hamburg, Germany
| | - Cong Luo
- Circular Resource Engineering and Management (CREM), Hamburg University of Technology (TUHH), Blohm Str. 15, 21079 Hamburg, Germany
| | | | - Ingo Fehr
- Siegwerk Druckfarben AG_Co.KGaA, Alfred-Keller-Str. 55, 53721 Siegburg, Germany
| | - Zhikai Chong
- Circular Resource Engineering and Management (CREM), Hamburg University of Technology (TUHH), Blohm Str. 15, 21079 Hamburg, Germany
| | - Magdalena Kitzberger
- Circular Resource Engineering and Management (CREM), Hamburg University of Technology (TUHH), Blohm Str. 15, 21079 Hamburg, Germany
| | - Ayah Alassali
- Circular Resource Engineering and Management (CREM), Hamburg University of Technology (TUHH), Blohm Str. 15, 21079 Hamburg, Germany
| | - Xuezhi Zhao
- Polymer Research Institute, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Ralf Leineweber
- Siegwerk Druckfarben AG_Co.KGaA, Alfred-Keller-Str. 55, 53721 Siegburg, Germany
| | - Yujun Feng
- Polymer Research Institute, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China
| | - Kerstin Kuchta
- Circular Resource Engineering and Management (CREM), Hamburg University of Technology (TUHH), Blohm Str. 15, 21079 Hamburg, Germany
| |
Collapse
|
5
|
Freudenthaler PJ, Fischer J, Lang RW. Assessment of Commercially Available Polyethylene Recyclates for Blow Molding Applications by a Novel Environmental Stress Cracking Method. Polymers (Basel) 2022; 15:polym15010046. [PMID: 36616396 PMCID: PMC9823600 DOI: 10.3390/polym15010046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
The transition to a circular economy has a major impact on waste management and the reuse of materials. New mandatory recycling targets for plastics will lead to a high availability of recyclates. For these recyclates, useful applications need to be found. One potential application for recyclates is blow molding bottles as packaging for non-food contents. This study investigates commercially available post-consumer high-density polyethylene recyclates together with virgin blow molding grades in terms of their short-term mechanical properties and environmental stress cracking resistance. While the short-term mechanical properties showed only slightly lower performance than the tested virgin grades, the overall environmental stress cracking failure times of the recyclates were much lower compared to virgin materials, even though the crack-growth kinetics could be similar. Although neither the tensile nor the notched impact strength results of the two polyethylene recyclates revealed large differences, the stress intensity-factor-dependent crack-growth rates of both materials were significantly different.
Collapse
|
6
|
Bashirgonbadi A, Saputra Lase I, Delva L, Van Geem KM, De Meester S, Ragaert K. Quality evaluation and economic assessment of an improved mechanical recycling process for post-consumer flexible plastics. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 153:41-51. [PMID: 36049271 DOI: 10.1016/j.wasman.2022.08.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/06/2022] [Accepted: 08/20/2022] [Indexed: 05/28/2023]
Abstract
Packaging represents the largest fraction of plastic waste in Europe. Currently, mechanical recycling schemes are mainly focused on the recovery of rigid packaging (like bottles), while for flexible packaging, also called films, recycling rates remain very low. Existing mechanical recycling technologies for these films are quite basic, especially in the case of complicated post-consumer flexible plastics (PCFP) waste, leading to regranulate qualities that are often subpar for renewed use in demanding film applications. In this study, the technical and economic value of an improved mechanical recycling process (additional sorting, hot washing, and improved extrusion) of PCFPs is investigated. The quality of the four types of resulting regranulates is evaluated for film and injection molding applications. The obtained Polyethylene-rich regranulates in blown films offer more flexibility (45-60%), higher ductility (27-55%), and enhanced tensile strength (5-51%), compared to the conventional mechanical recycling process. Likewise, for injection molded samples, they exhibit more flexibility (19-49%), enhanced ductility (7 to 20 times), and higher impact strength (1.8 to 3.8 times). An economic assessment is made between the obtained increased market value and the capital investment required. It is shown that the economic value can be increased by 5-38% through this improved recycling process. Overall, the study shows that it is possible to increase the mechanical recycling quality of PCFP in an economically viable way, thus opening the way for new application routes and overall increased recycling rates.
Collapse
Affiliation(s)
- Amir Bashirgonbadi
- Laboratory for Chemical Technology (LCT), Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium; Circular Plastics, Department of Circular Chemical Engineering (CCE), Faculty of Science and Engineering, Maastricht University, Geleen, the Netherlands
| | - Irdanto Saputra Lase
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Campus Kortrijk, Belgium
| | - Laurens Delva
- Laboratory for Chemical Technology (LCT), Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Kevin M Van Geem
- Laboratory for Chemical Technology (LCT), Department of Materials, Textiles and Chemical Engineering, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Steven De Meester
- Laboratory for Circular Process Engineering (LCPE), Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Campus Kortrijk, Belgium; Circular Plastics, Department of Circular Chemical Engineering (CCE), Faculty of Science and Engineering, Maastricht University, Geleen, the Netherlands
| | - Kim Ragaert
- Circular Plastics, Department of Circular Chemical Engineering (CCE), Faculty of Science and Engineering, Maastricht University, Geleen, the Netherlands.
| |
Collapse
|
7
|
Kukhta NA, Luscombe CK. Gaining control over conjugated polymer morphology to improve the performance of organic electronics. Chem Commun (Camb) 2022; 58:6982-6997. [PMID: 35604084 DOI: 10.1039/d2cc01430k] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Conjugated polymers (CPs) are widely used in various domains of organic electronics. However, the performance of organic electronic devices can be variable due to the lack of precise predictive control over the polymer microstructure. While the chemical structure of CPs is important, CP microstructure also plays an important role in determining the charge-transport, optical and mechanical properties suitable for a target device. Understanding the interplay between CP microstructure and the resulting properties, as well as predicting and targeting specific polymer morphologies, would allow current comprehension of organic electronic device performance to be improved and potentially enable more facile device optimization and fabrication. In this Feature Article, we highlight the importance of investigating CP microstructure, discuss previous developments in the field, and provide an overview of the key aspects of the CP microstructure-property relationship, carried out in our group over recent years.
Collapse
Affiliation(s)
- Nadzeya A Kukhta
- Materials Science and Engineering Department, University of Washington, Seattle, Washington 98195-2120, USA
| | - Christine K Luscombe
- pi-Conjugated Polymers Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, 904-0495, Japan.
| |
Collapse
|