1
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Jang YJ, Nguyen S, Hillmyer MA. Chemically Recyclable Linear and Branched Polyethylenes Synthesized from Stoichiometrically Self-Balanced Telechelic Polyethylenes. J Am Chem Soc 2024; 146:4771-4782. [PMID: 38323928 DOI: 10.1021/jacs.3c12660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
High-density polyethylene (HDPE) is a widely used commercial plastic due to its excellent mechanical properties, chemical resistance, and water vapor barrier properties. However, less than 10% of HDPE is mechanically recycled, and the chemical recycling of HDPE is challenging due to the inherent strength of the carbon-carbon backbone bonds. Here, we report chemically recyclable linear and branched HDPE with sparse backbone ester groups synthesized from the transesterification of telechelic polyethylene macromonomers. Stoichiometrically self-balanced telechelic polyethylenes underwent transesterification polymerization to produce the PE-ester samples with high number-average molar masses of up to 111 kg/mol. Moreover, the transesterification polymerization of the telechelic polyethylenes and the multifunctional diethyl 5-(hydroxymethyl)isophthalate generated branched PE-esters. Thermal and mechanical properties of the PE-esters were comparable to those of commercial HDPE and tunable through control of the ester content in the backbone. In addition, branched PE-esters showed higher levels of melt strain hardening compared with linear versions. The PE-ester was depolymerized into telechelic macromonomers through straightforward methanolysis, and the resulting macromonomers could be effectively repolymerized to generate a high molar mass recycled PE-ester sample. This is a new and promising method for synthesizing and recycling high-molar-mass linear and branched PE-esters, which are competitive with HDPE and have easily tailorable properties.
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Affiliation(s)
- Yoon-Jung Jang
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Sam Nguyen
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Marc A Hillmyer
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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2
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Ho KH, Lu X, Lau SK. In Situ Dispersion of Lignin in Polypropylene via Supercritical CO 2 Extrusion Foaming: Effects of Lignin on Cell Nucleation and Foam Compression Properties. Polymers (Basel) 2023; 15:polym15081813. [PMID: 37111960 PMCID: PMC10145137 DOI: 10.3390/polym15081813] [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: 02/27/2023] [Revised: 03/27/2023] [Accepted: 04/04/2023] [Indexed: 04/29/2023] Open
Abstract
Supercritical CO2 (scCO2) extrusion foamed high-melt-strength (HMS) polypropylene (PP) often suffers from low cell density, large cell sizes, and poor cell structure uniformity due to the poor nucleation rates of CO2 in the PP. To remedy this, various inorganic fillers have been used as heterogeneous nucleation agents. Although their efficient nucleation effects have been demonstrated, the preparation of these fillers causes some adverse effects on the environment/human health or involves relatively expensive processes or non-eco-friendly chemicals. In this work, biomass-based lignin is studied as a sustainable, lightweight, and cost-effective nucleating agent. It is found that scCO2 could assist in situ dispersion of lignin in the PP in the foaming process, leading to significantly increased cell density, smaller cells, and improved cell uniformity. The Expansion Ratio is also simultaneously improved due to reduced diffusive gas loss. The PP/lignin foams with low lignin loadings exhibit higher compression moduli and plateau strengths than the PP foams with the same densities owing to the improved cell uniformity and probably also the reinforcing effect of the small lignin particles in cell walls. Moreover, the energy absorption capability of the PP/lignin foam with 1 wt% lignin could match the PP foam with similar compression plateau strengths; even the density of the former is 28% lower than the latter. Therefore, this work provides a promising approach to a cleaner and more sustainable production of HMS PP foams.
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Affiliation(s)
- Keen Hoe Ho
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Singapore Institute of Manufacturing Technology, Agency for Science, Technology and Research, 5 CleanTech Loop #01-01, CleanTech Two Block B, Singapore 636732, Singapore
| | - Xuehong Lu
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Soo Khim Lau
- Singapore Institute of Manufacturing Technology, Agency for Science, Technology and Research, 5 CleanTech Loop #01-01, CleanTech Two Block B, Singapore 636732, Singapore
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3
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Sangroniz L, Fernández M, Santamaria A. Polymers and rheology: A tale of give and take. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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4
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Röpert MC, Hirschberg V, Schußmann MG, Wilhelm M. Impact of Topological Parameters on Melt Rheological Properties and Foamability of PS POM-POMs. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Marie-Christin Röpert
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 18, Karlsruhe 76131, Germany
| | - Valerian Hirschberg
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 18, Karlsruhe 76131, Germany
| | - Max G. Schußmann
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 18, Karlsruhe 76131, Germany
| | - Manfred Wilhelm
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 18, Karlsruhe 76131, Germany
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5
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Lin W, Hamamoto Y, Hikima Y, Ohshima M. Improvement of the surface quality of foam injection molded products from a material property perspective. POLYM ENG SCI 2022. [DOI: 10.1002/pen.26183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Weiyuan Lin
- Department of Chemical Engineering Kyoto University Kyoto Japan
| | | | - Yuta Hikima
- Department of Chemical Engineering Kyoto University Kyoto Japan
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6
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Faust L, Röpert M, Esfahani MK, Abbasi M, Hirschberg V, Wilhelm M. Comb and Branch‐on‐Branch Model Polystyrenes with Exceptionally High Strain Hardening Factor SHF > 1000 and their Impact on Physical Foaming. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Lorenz Faust
- Institute of Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
| | - Marie‐Christin Röpert
- Institute of Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
| | - Masood K. Esfahani
- Institute of Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
| | - Mahdi Abbasi
- Borealis Polyolefine GmbH Innovation Headquarters Linz 4021 Austria
| | - Valerian Hirschberg
- Institute of Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
| | - Manfred Wilhelm
- Institute of Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
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7
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Doyle L, Weidlich I, Di Maio E. Developing Insulating Polymeric Foams: Strategies and Research Needs from a Circular Economy Perspective. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6212. [PMID: 36143523 PMCID: PMC9502929 DOI: 10.3390/ma15186212] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
Insulating polymeric foams have an important role to play in increasing energy efficiency and therefore contributing to combating climate change. Their development in recent years has been driven towards the reduction of thermal conductivity and achievement of the required mechanical properties as main targets towards sustainability. This perception of sustainability has overseen the choice of raw materials, which are often toxic, or has placed research efforts on optimizing one constituent while the other necessary reactants remain hazardous. The transition to the circular economy requires a holistic understanding of sustainability and a shift in design methodology and the resulting research focus. This paper identifies research needs and possible strategies for polymeric foam development compatible with Circular Product Design and Green Engineering, based on an extensive literature review. Identified research needs include material characterization of a broader spectrum of polymer melt-gas solutions, ageing behavior, tailoring of the polymer chains, detailed understanding and modeling of the effects of shear on cell nucleation, and the upscaling of processing tools allowing for high and defined pressure drop rates.
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Affiliation(s)
- Lucia Doyle
- Technical Infrastructure Management, HafenCity University, 20457 Hamburg, Germany
| | - Ingo Weidlich
- Technical Infrastructure Management, HafenCity University, 20457 Hamburg, Germany
| | - Ernesto Di Maio
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, University of Naples Federico II, 80138 Naples, Italy
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8
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Huang P, Wu F, Su Y, Luo H, Lan X, Lee PC, Zheng W. Supercritical
CO
2
foaming of open‐cell polypropylene/ethylene propylene diene monomer composite foams with oriented cellular structures for water treatment. J Appl Polym Sci 2022. [DOI: 10.1002/app.53068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Pengke Huang
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang Province China
| | - Fei Wu
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang Province China
| | - Yaozhuo Su
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang Province China
| | - Haibin Luo
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang Province China
| | - Xiaoqin Lan
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang Province China
| | - Patrick C. Lee
- Multifunctional Composites Manufacturing Laboratory, Department of Mechanical and Industrial Engineering University of Toronto Toronto Ontario Canada
| | - Wenge Zheng
- Ningbo Key Lab of Polymer Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang Province China
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9
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Lamnawar K, Maazouz A. Rheology and Processing of Polymers. Polymers (Basel) 2022; 14:polym14122327. [PMID: 35745903 PMCID: PMC9228071 DOI: 10.3390/polym14122327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 06/06/2022] [Indexed: 02/01/2023] Open
Abstract
I am so glad to share with you our Special Issue entitled 'Rheology and Processing of Polymers', which covers the latest developments in the field of rheology and polymer processing, highlighting cutting-edge research focusing on the processing of advanced polymers and their composites [...].
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Affiliation(s)
- Khalid Lamnawar
- CNRS, UMR 5223, Ingénierie des Matériaux Polymères, INSA Lyon, Université de Lyon, F-69621 Villeurbanne, France
- University Jean Monnet, F-42100 Saint-Étienne, France
- Correspondence:
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10
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Kirchberg A, Esfahani MK, Röpert M, Wilhelm M, Meier MAR. Sustainable Synthesis of Non‐Isocyanate Polyurethanes based on Renewable 2,3‐Butanediol. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Anja Kirchberg
- Laboratory of Applied Chemistry Institute of Organic Chemistry (IOC) Karlsruhe Institute of Technology (KIT) Straße am Forum 7 Karlsruhe 76131 Germany
| | - Masood Khabazian Esfahani
- Institute for Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
| | - Marie‐Christin Röpert
- Institute for Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
| | - Manfred Wilhelm
- Institute for Chemical Technology and Polymer Chemistry (ITCP) Karlsruhe Institute of Technology (KIT) Engesserstraße 18 76131 Karlsruhe Germany
| | - Michael A. R. Meier
- Laboratory of Applied Chemistry Institute of Organic Chemistry (IOC) Karlsruhe Institute of Technology (KIT) Straße am Forum 7 Karlsruhe 76131 Germany
- Laboratory of Applied Chemistry Institute of Biological and Chemical System‐Functional Molecular Systems (IBCS‐FMS) Karlsruhe Institute of Technology (KIT) Hermann‐von‐Helmholtz‐Platz 1 Eggenstein‐Leopoldshafen 76344 Germany
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11
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Guo P, Xu Y, Lyu M, Zhang S. Fabrication of Expanded Ethylene–Propylene–Butene-1 Copolymer Bead. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.1c04060] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peng Guo
- Beijing Research Institute of Chemical Industry, SINOPEC, Beijing 100013, People’s Republic of China
| | - Yaohui Xu
- Beijing Research Institute of Chemical Industry, SINOPEC, Beijing 100013, People’s Republic of China
| | - Mingfu Lyu
- Beijing Research Institute of Chemical Industry, SINOPEC, Beijing 100013, People’s Republic of China
| | - Shijun Zhang
- Beijing Research Institute of Chemical Industry, SINOPEC, Beijing 100013, People’s Republic of China
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12
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Farahani M, Jahani Y, Kakanejadifard A, Ohshima M. Self-Assembly of Temperature Sensitive Additives in Polypropylene Melt and Its Influence on Viscoelasticity. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.1c03927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mina Farahani
- Faculty of Polymer Processing, Iran Polymer and Petrochemical Institute, Tehran 13115-14977, Iran
| | - Yousef Jahani
- Faculty of Polymer Processing, Iran Polymer and Petrochemical Institute, Tehran 13115-14977, Iran
| | - Ali Kakanejadifard
- Department of Chemistry, Faculty of Science, Lorestan University, Khorramabad 68151-44316, Iran
| | - Masahiro Ohshima
- Department of Chemical Engineering, KYOTO University, Kyoto 615-8530, Japan
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13
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Kweon MS, Embabi M, Shivokhin ME, Gupta A, Yan X, Pehlert G, Lee PC. Tuning High and Low Temperature Foaming Behavior of Linear and Long-Chain Branched Polypropylene via Partial and Complete Melting. Polymers (Basel) 2021; 14:polym14010044. [PMID: 35012070 PMCID: PMC8747320 DOI: 10.3390/polym14010044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/13/2021] [Accepted: 12/20/2021] [Indexed: 11/16/2022] Open
Abstract
While existing foam studies have identified processing parameters, such as high-pressure drop rate, and engineering measures, such as high melt strength, as key factors for improving foamability, there is a conspicuous absence of studies that directly relate foamability to material properties obtained from fundamental characterization. To bridge this gap, this work presents batch foaming studies on one linear and two long-chain branched polypropylene (PP) resins to investigate how foamability is affected by partial melting (Method 1) and complete melting followed by undercooling (Method 2). At temperatures above the melting point, similar expansion was obtained using both foaming procedures within each resin, while the PP with the highest strain hardening ratio (13) exhibited the highest expansion ratio (45 ± 3). At low temperatures, the foamability of all resins was dramatically improved using Method 2 compared to Method 1, due to access to lower foaming temperatures (<150 °C) near the crystallization onset. Furthermore, Method 2 resulted in a more uniform cellular structure over a wider temperature range (120–170 °C compared to 155–175 °C). Overall, strong extensional hardening and low onset of crystallization were shown to give rise to foamability at high and low temperatures, respectively, suggesting that both characteristics can be appropriately used to tune the foamability of PP in industrial foaming applications.
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Affiliation(s)
- Mu Sung Kweon
- Multifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada; (M.S.K.); (M.E.)
| | - Mahmoud Embabi
- Multifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada; (M.S.K.); (M.E.)
| | - Maksim E. Shivokhin
- ExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USA; (M.E.S.); (A.G.); (X.Y.); (G.P.)
| | - Anvit Gupta
- ExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USA; (M.E.S.); (A.G.); (X.Y.); (G.P.)
| | - Xuejia Yan
- ExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USA; (M.E.S.); (A.G.); (X.Y.); (G.P.)
| | - George Pehlert
- ExxonMobil Chemical Company, 5200 Bayway Drive, Baytown, TX 77520, USA; (M.E.S.); (A.G.); (X.Y.); (G.P.)
| | - Patrick C. Lee
- Multifunctional Composites Manufacturing Laboratory (MCML), Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Toronto, ON M5S 3G8, Canada; (M.S.K.); (M.E.)
- Correspondence: ; Tel.: +1-(416)-946-5407
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14
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Liu B, Jiang T, Zeng X, Deng R, Gu J, Gong W, He L. Polypropylene/thermoplastic polyester elastomer blend: Crystallization properties, rheological behavior, and foaming performance. POLYM ADVAN TECHNOL 2021. [DOI: 10.1002/pat.5240] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Bujin Liu
- The Institute of Materials and Metallurgy of Guizhou University Guiyang China
- National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang China
| | - Tuanhui Jiang
- National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang China
| | - Xiangbu Zeng
- National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang China
| | - Rong Deng
- The Institute of Materials and Metallurgy of Guizhou University Guiyang China
- National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang China
| | - Jun Gu
- The Institute of Materials and Metallurgy of Guizhou University Guiyang China
- National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang China
| | - Wei Gong
- The Institute of Materials and Construction of Guizhou Normal University Guiyang China
| | - Li He
- The Institute of Materials and Metallurgy of Guizhou University Guiyang China
- National Engineering Research Center for Compounding and Modification of Polymer Materials Guiyang China
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15
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Dual role of PDMS on improving supercritical CO2 foaming of polypropylene: CO2-philic additive and crystallization nucleating agent. J Supercrit Fluids 2020. [DOI: 10.1016/j.supflu.2020.104888] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Dörr D, Kuhn U, Altstädt V. Rheological Study of Gelation and Crosslinking in Chemical Modified Polyamide 12 Using a Multiwave Technique. Polymers (Basel) 2020; 12:polym12040855. [PMID: 32272715 PMCID: PMC7240435 DOI: 10.3390/polym12040855] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 11/24/2022] Open
Abstract
When processing particular polymers, it may be necessary to increase the molecular weight, for example, during polymer recycling or foaming. Chemical additives such as chain extenders (CE) are often used to build up the molecular weight during reactive extrusion. One issue of chain extenders, however, is that they can cause gelation or crosslinking of the polymer during processes with long residence times. This can lead to strong process fluctuations, undesired process shutdowns due to uncontrollable torque and pressure fluctuations and finally consistent material quality cannot be guaranteed. To measure and understand the reactivity between the polymer and the CE a rheological test can help. However, the standard gel point evaluation used for thermosets by examining the point of intersection of storage- and loss modules is not suitable, as this method is frequency-dependent. This study uses a multiwave rheology test to identify the gel-point more reliably. Both evaluation methods were compared on a polyamide 12 system, which is modified with an industrially relevant chain extender. The results show that the multiwave test can be applied on a chemical modified thermoplastic system and that the material system indicates a general tendency to crosslink. The frequency-independent gel-point evaluation shows that the gel-point itself is dependent on the processing temperature. Finally, it was possible to detect undesired side reactions, which are not recognizable with the standard testing method. Both findings are directly relevant for the reactive extrusion process and help to understand the mechanism of gelation.
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Affiliation(s)
- Dominik Dörr
- Department of Polymer Engineering, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany; (D.D.); (U.K.)
| | - Ute Kuhn
- Department of Polymer Engineering, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany; (D.D.); (U.K.)
| | - Volker Altstädt
- Department of Polymer Engineering, University of Bayreuth, Universitätsstrasse 30, 95447 Bayreuth, Germany; (D.D.); (U.K.)
- Bavarian Polymer Institute, Universitätsstrasse 30, 95447 Bayreuth, Germany
- Correspondence: ; Tel.: +49-921-55-7471
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