1
|
Vialon T, Sun H, Formon GJM, Galanopoulo P, Guibert C, Averseng F, Rager MN, Percot A, Guillaneuf Y, Van Zee NJ, Nicolaÿ R. Upcycling Polyolefin Blends into High-Performance Materials by Exploiting Azidotriazine Chemistry Using Reactive Extrusion. J Am Chem Soc 2024; 146:2673-2684. [PMID: 38238037 DOI: 10.1021/jacs.3c12303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
The revalorization of incompatible polymer blends is a key obstacle in realizing a circular economy in the plastics industry. Polyolefin waste is particularly challenging because it is difficult to sort into its constituent components. Untreated blends of polyethylene and polypropylene typically exhibit poor mechanical properties that are suitable only for low-value applications. Herein, we disclose a simple azidotriazine-based grafting agent that enables polyolefin blends to be directly upcycled into high-performance materials by using reactive extrusion at industrially relevant processing temperatures. Based on a series of model experiments, the azidotriazine thermally decomposes to form a triplet nitrene species, which subsequently undergoes a complex mixture of grafting, oligomerization, and cross-linking reactions; strikingly, the oligomerization and cross-linking reactions proceed through the formation of nitrogen-nitrogen bonds. When applied to polyolefin blends during reactive extrusion, this combination of reactions leads to the generation of amorphous, phase-separated nanostructures that tend to exist at polymer-polymer interfaces. These nanostructures act as multivalent cross-linkers that reinforce the resulting material, leading to dramatically improved ductility compared with the untreated blends, along with high dimensional stability at high temperatures and excellent mechanical recyclability. We propose that this unique behavior is derived from the thermomechanically activated reversibility of the nitrogen-nitrogen bonds that make up the cross-linking structures. Finally, the scope of this chemistry is demonstrated by applying it to ternary polyolefin blends as well as postconsumer polyolefin feedstocks.
Collapse
Affiliation(s)
- Thomas Vialon
- Chimie Moléculaire, Macromoléculaire, Matériaux, ESPCI Paris, Université PSL, CNRS, 75005Paris ,France
| | - Huidi Sun
- Chimie Moléculaire, Macromoléculaire, Matériaux, ESPCI Paris, Université PSL, CNRS, 75005Paris ,France
| | - Georges J M Formon
- Chimie Moléculaire, Macromoléculaire, Matériaux, ESPCI Paris, Université PSL, CNRS, 75005Paris ,France
| | - Paul Galanopoulo
- Chimie Moléculaire, Macromoléculaire, Matériaux, ESPCI Paris, Université PSL, CNRS, 75005Paris ,France
| | - Clément Guibert
- Laboratoire de Réactivité de Surface, UMR 7197, Sorbonne Université, CNRS, 75005 Paris, France
| | - Frédéric Averseng
- Laboratoire de Réactivité de Surface, UMR 7197, Sorbonne Université, CNRS, 75005 Paris, France
| | - Marie-Noelle Rager
- NMR Facility, Chimie ParisTech, Université PSL, CNRS, 75005Paris ,France
| | - Aline Percot
- MONARIS, UMR 8233, Sorbonne Université, CNRS, 75005Paris ,France
| | - Yohann Guillaneuf
- Institut de Chimie Radicalaire UMR 7273,Aix-Marseille Université, CNRS, 13397Marseille ,France
| | - Nathan J Van Zee
- Chimie Moléculaire, Macromoléculaire, Matériaux, ESPCI Paris, Université PSL, CNRS, 75005Paris ,France
| | - Renaud Nicolaÿ
- Chimie Moléculaire, Macromoléculaire, Matériaux, ESPCI Paris, Université PSL, CNRS, 75005Paris ,France
| |
Collapse
|
2
|
Zou W, Tupper A, Rebello NJ, Ranasinghe DS, Green WH, Couch C, Olsen BD. Multiscale Modeling and Characterization of Radical-Initiated Modification of Molten Polyolefins. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Weizhong Zou
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - Amber Tupper
- Cooper-Standard Automotive Inc., Livonia, Michigan 48150, United States
| | - Nathan J. Rebello
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - Duminda S. Ranasinghe
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - William H. Green
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - Christopher Couch
- Cooper-Standard Automotive Inc., Livonia, Michigan 48150, United States
| | - Bradley D. Olsen
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
| |
Collapse
|
3
|
Sample CS, Kellstedt EA, Hillmyer MA. Tandem ROMP/Hydrogenation Approach to Hydroxy-Telechelic Linear Polyethylene. ACS Macro Lett 2022; 11:608-614. [PMID: 35570818 DOI: 10.1021/acsmacrolett.2c00144] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydroxy-telechelic polyalkenamers have long been synthesized using ring-opening metathesis polymerization (ROMP) in the presence of an acyclic olefin chain-transfer agent (CTA); however, this route typically requires protected diols in the CTA due to the challenge of alcohol-mediated degradation of ruthenium metathesis catalysts that can not only deactivate the catalysts, but also compromise the CTA. We demonstrate the synthesis and implementation of a new hydroxyl-containing CTA in which extended methylene spacers isolate the olefin and alcohol moieties to mitigate decomposition pathways. This CTA enabled the direct ROMP synthesis of hydroxy-telechelic polycyclooctene with controlled chain lengths dictated by the initial ratio of monomer to CTA. The elimination of protection/deprotection steps resulted in improved atom economy. Subsequent hydrogenation of the backbone olefins was performed by a one-pot, catalytic approach employing the ruthenium complex used for the initial ROMP. The resultant approach is a streamlined, atom-economic, and low-waste route to hydroxy-telechelic linear polyethylene that uses a green solvent, succeeds with miniscule quantities of catalyst (0.005 mol %), and requires no additional purification steps.
Collapse
Affiliation(s)
- Caitlin S. Sample
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Elizabeth A. Kellstedt
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| | - Marc A. Hillmyer
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431, United States
| |
Collapse
|
4
|
Kim HJ, Hillmyer MA, Ellison CJ. Enhanced Polyester Degradation through Transesterification with Salicylates. J Am Chem Soc 2021; 143:15784-15790. [PMID: 34529416 DOI: 10.1021/jacs.1c07229] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Polyesters constitute nearly 10% of the global plastic market, but most are essentially non-degradable under ambient conditions or in engineered environments. A range of degradable polyesters have been developed as more sustainable alternatives; however, limitations of practical degradability and scalability have hindered their viability. Here, we utilized transesterification approaches, including in situ polymerization-transesterification, between a salicylate and a polyester to incorporate salicylate units into commercial polyester backbones. The strategy is scalable and practically relevant given that high molar mass polymers can be obtained from melt-processing of commercial polyesters using common compounders or extruders. Polylactide containing sparse salicylate moieties shows enhanced hydrolytic degradability in aqueous buffer, seawater, and alkaline solutions without sacrificing the thermal, mechanical, and O2 barrier properties of the parent material. Additionally, salicylate sequences were incorporated into polycaprolactone and a derivative of poly(ethylene terephthalate), and those modified polymers also exhibited facile degradation behavior in alkaline solution, further expanding the scope of this approach. This work provides insights and direction for the development of high-performance yet more sustainable and degradable alternatives to conventional polyesters.
Collapse
|
5
|
Zhang WB, Luo J, Wang YM, Zhu XZ, Zhang C, Liu J, Ni ML, Zhang GH. Hydroxyl-terminated Polyethylenes Bearing Functional Side Groups: Facile Synthesis and Their Properties. CHINESE JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1007/s10118-021-2572-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
6
|
Noble BB, Nesvadba P, Coote ML. Mechanistic Insights into N-Acyloxyamine-Initiated Controlled Degradation of Polypropylene: The Unexpected Role of Keto-Enol Tautomerization in Carboxylate Radical Chemistry. J Org Chem 2020; 85:2338-2346. [PMID: 31860796 DOI: 10.1021/acs.joc.9b03052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Controlled degradation of polypropylene (PP) is used industrially to improve the properties of crude PP. While this degradation is traditionally initiated by organic peroxides, N-acyloxyamines are now preferred due to their greater stability. However, their mechanism of action remains unclear. Using high-level ab initio calculations, we show that N-O homolysis is the most likely fragmentation pathway available to N-acyloxyamines, in contrast to the more usual C-O homolysis observed for the closely related N-alkoxyamines. This would, in theory, generate aminyl and carboxylate radicals, with the latter undergoing decarboxylation to generate methyl radicals. However, the enol forms of N-acyloxyamines are significantly less thermally stable, having bond dissociation free energies that are over 50 kJ/mol below those of their keto equivalents. Under conditions where keto-enol tautomerism is feasible, enol N-O homolysis, which forms the more stable acetic acid radical, would be the dominant degradation pathway. This reveals the crucial and underappreciated role that polar impurities play in the initiation process of enolizable initiators and may explain contradictory observations in the experimental literature. The product aminyl radicals are susceptible to β-fragmentation, releasing alkyl radicals and affording imines, which in turn are susceptible to allylic H-abstraction and further β-fragmentation leading to dialkylpyridines as the ultimate degradation products.
Collapse
Affiliation(s)
- Benjamin B Noble
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry , Australian National University , Canberra , Australian Capital Territory 2601 , Australia
| | - Peter Nesvadba
- BASF Schweiz AG , WSH-2093.2.16, Rheinfelderstrasse , 4133 Schweizerhalle , Switzerland
| | - Michelle L Coote
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry , Australian National University , Canberra , Australian Capital Territory 2601 , Australia
| |
Collapse
|
7
|
Plummer CM, Li L, Chen Y. The post-modification of polyolefins with emerging synthetic methods. Polym Chem 2020. [DOI: 10.1039/d0py01279c] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This Perspective highlights the present state of polyolefin post-modification research, especially concerning recently developed C–H functionalization chemistry. Remaining challenges and emerging strategies within the field have also been discussed.
Collapse
Affiliation(s)
- Christopher M. Plummer
- School of Materials Science and Engineering
- Sun Yat-sen University
- Guangzhou 510275
- China
- Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education
| | - Le Li
- Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education
- Sun Yat-sen University
- Guangzhou 510275
- China
- School of Chemistry
| | - Yongming Chen
- School of Materials Science and Engineering
- Sun Yat-sen University
- Guangzhou 510275
- China
- Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education
| |
Collapse
|