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Whitfield R, Jones GR, Truong NP, Manring LE, Anastasaki A. Solvent-Free Chemical Recycling of Polymethacrylates made by ATRP and RAFT polymerization: High-Yielding Depolymerization at Low Temperatures. Angew Chem Int Ed Engl 2023; 62:e202309116. [PMID: 37523176 DOI: 10.1002/anie.202309116] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/31/2023] [Accepted: 07/31/2023] [Indexed: 08/01/2023]
Abstract
Although controlled radical polymerization is an excellent tool to make precision polymeric materials, reversal of the process to retrieve the starting monomer is far less explored despite the significance of chemical recycling. Here, we investigate the bulk depolymerization of RAFT and ATRP-synthesized polymers under identical conditions. RAFT-synthesized polymers undergo a relatively low-temperature solvent-free depolymerization back to monomer thanks to the partial in situ transformation of the RAFT end-group to macromonomer. Instead, ATRP-synthesized polymers can only depolymerize at significantly higher temperatures (>350 °C) through random backbone scission. To aid a more complete depolymerization at even lower temperatures, we performed a facile and quantitative end-group modification strategy in which both ATRP and RAFT end-groups were successfully converted to macromonomers. The macromonomers triggered a lower temperature bulk depolymerization with an onset at 150 °C yielding up to 90 % of monomer regeneration. The versatility of the methodology was demonstrated by a scalable depolymerization (≈10 g of starting polymer) retrieving 84 % of the starting monomer intact which could be subsequently used for further polymerization. This work presents a new low-energy approach for depolymerizing controlled radical polymers and creates many future opportunities as high-yielding, solvent-free and scalable depolymerization methods are sought.
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Affiliation(s)
- Richard Whitfield
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
| | - Glen R Jones
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
| | - Nghia P Truong
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
| | | | - Athina Anastasaki
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
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2
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Hassan S, Najabat Ali M, Ghafoor B. An appraisal of polymers of DES technology and their impact on drug release kinetics. INT J POLYM MATER PO 2022. [DOI: 10.1080/00914037.2022.2090941] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sadia Hassan
- Department of Biomedical Engineering and Sciences, School of Mechanical and Manufacturing Engineering, National University of Sciences and Technology, Islamabad, Pakistan
| | - Murtaza Najabat Ali
- Department of Biomedical Engineering and Sciences, School of Mechanical and Manufacturing Engineering, National University of Sciences and Technology, Islamabad, Pakistan
| | - Bakhtawar Ghafoor
- Department of Biomedical Engineering and Sciences, School of Mechanical and Manufacturing Engineering, National University of Sciences and Technology, Islamabad, Pakistan
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3
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Kubiak JM, Li B, Suazo M, Macfarlane RJ. Polymer Grafted Nanoparticle Composites with Enhanced Thermal and Mechanical Properties. ACS APPLIED MATERIALS & INTERFACES 2022; 14:21535-21543. [PMID: 35500102 DOI: 10.1021/acsami.2c03797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The distribution of filler particles within a polymer matrix nanocomposite has a profound influence on the properties and processability of the material. While filler aggregation and percolation can significantly enhance particular functionalities such as thermal and electrical conductivity, the formation of larger filler clusters and networks can also impair mechanical properties like strength and toughness and can also increase the difficulty of processing. Here, a strategy is presented for the preparation of functional composites that enhance thermal conductivity over polymer alone, without negatively affecting mechanical performance or processability. Thermal cross-linking of self-suspended polymer grafted nanoparticles is used to prepare highly filled (>50 vol %) macroscopic nanocomposites with homogeneously dispersed, non-percolating alumina particles in an organic matrix. The initial composites use low glass transition temperature polymer grafts and thus are flexible and easily shaped by thermoforming methods. However, after thermal aging, the resulting materials display high stiffness (>10 GPa) and enhanced thermal conductivity (>100% increase) and also possess mechanical strength similar to commodity plastics. Moreover, the covalent bonding between matrix and filler allows for the significant elevation of thermal conductivity despite the extensive interfacial area in the nanocomposite. The thermal aging of polymer grafted nanoparticles is therefore a promising method for producing easily processable, mechanically sturdy, and macroscopic nanocomposites with improved thermal conductivity.
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Affiliation(s)
- Joshua M Kubiak
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Buxuan Li
- Department of Mechanical Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Mathew Suazo
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Robert J Macfarlane
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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4
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Zeljko M, Bulatović VO, Blažic R, Blagojević SL. The development of eco‐friendly
UV
‐protective polyacrylate/rutile
TiO
2
coating. J Appl Polym Sci 2022. [DOI: 10.1002/app.52393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Martina Zeljko
- Faculty of Chemical Engineering and Technology University of Zagreb Zagreb Croatia
| | | | - Roko Blažic
- Faculty of Chemical Engineering and Technology University of Zagreb Zagreb Croatia
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5
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Adsorption mechanism of essence‐containing poly (butyl methacrylate) nanocapsules on cotton fabric surface. J Appl Polym Sci 2022. [DOI: 10.1002/app.51483] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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6
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De Keer L, Van Steenberge P, Reyniers MF, Gryn'ova G, Aitken HM, Coote ML. New mechanism for autoxidation of polyolefins: kinetic Monte Carlo modelling of the role of short-chain branches, molecular oxygen and unsaturated moieties. Polym Chem 2022. [DOI: 10.1039/d1py01659h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Using quantum-chemical calculations and kinetic modelling, we reveal the dominant reaction pathway in polymer autoxidation, (i) whether oxygen promotes or hamper degradation and (ii) how defects in the polymer backbone affect degradation.
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Affiliation(s)
- Lies De Keer
- Department of Materials, Textiles and Chemical Engineering, Laboratory for Chemical Technology, Ghent University, Technologiepark 125, 9052 Zwijnaarde, Belgium
| | - Paul Van Steenberge
- Department of Materials, Textiles and Chemical Engineering, Laboratory for Chemical Technology, Ghent University, Technologiepark 125, 9052 Zwijnaarde, Belgium
| | - Marie-Françoise Reyniers
- Department of Materials, Textiles and Chemical Engineering, Laboratory for Chemical Technology, Ghent University, Technologiepark 125, 9052 Zwijnaarde, Belgium
| | - Ganna Gryn'ova
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- Heidelberg Institute for Theoretical Studies (HITS gGmbH), and Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
| | - Heather M. Aitken
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Michelle L. Coote
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
- Heidelberg Institute for Theoretical Studies (HITS gGmbH), and Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
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7
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Zeljko M, Ocelić Bulatović V, Špada V, Blagojević SL. Environmentally Friendly UV-Protective Polyacrylate/TiO 2 Nanocoatings. Polymers (Basel) 2021; 13:2609. [PMID: 34451149 PMCID: PMC8400131 DOI: 10.3390/polym13162609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 11/16/2022] Open
Abstract
The development of coatings that maintain the attractive natural appearance of wood while providing ultraviolet (UV) protection is extremely important for the widespread use of wood products. In this study, the influence of different types (powder form and aqueous dispersions) of TiO2 in an amount of 1.0 wt% by monomer weight on the properties of environmentally friendly polyacrylate (PA)/TiO2 emulsions prepared by ex situ and in situ polymerization, as well as on the UV-protective properties of the coating films, was investigated. The results showed that the addition of TiO2 significantly affected the particle size distribution of PA and the viscosity of PA varied according to the preparation method. Compared with the ex situ preparation method, in situ polymerization provides better dispersibility of TiO2 nanoparticles in PA coating film, as well as a better UV protection effect and greater transparency of the coating films. Better morphology and transparency of nanocoating films were achieved by adding TiO2 nanofillers in aqueous dispersion as compared to the addition of TiO2 in powder form. An increase in the glass transition temperature during UV exposure associated with cross-linking in the polymer was less pronounced in the in situ-prepared coating films, confirming better UV protection, while the photocatalytic effect of TiO2 was more pronounced in the ex situ-prepared coating films. The results indicate that the method of preparation has a significant influence on the properties of the coating films.
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Affiliation(s)
- Martina Zeljko
- Faculty of Chemical Engineering and Technology, University of Zagreb, 10000 Zagreb, Croatia
| | | | - Vedrana Špada
- METRIS Materials Research Centre of Region of Istria, 52100 Pula, Croatia
| | - Sanja Lučić Blagojević
- Faculty of Chemical Engineering and Technology, University of Zagreb, 10000 Zagreb, Croatia
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8
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Robayo EA, Sierra CA, Perez LD. Synthesis of nanoparticles composed of a poly(methylmethacrylate-co-laurylmethacrylate) core and a polysiloxane shell as vehicles for limonene. REACT FUNCT POLYM 2020. [DOI: 10.1016/j.reactfunctpolym.2020.104571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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9
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Sabatini V, Pargoletti E, Comite V, Ortenzi MA, Fermo P, Gulotta D, Cappelletti G. Towards Novel Fluorinated Methacrylic Coatings for Cultural Heritage: A Combined Polymers and Surfaces Chemistry Study. Polymers (Basel) 2019; 11:polym11071190. [PMID: 31315250 PMCID: PMC6681005 DOI: 10.3390/polym11071190] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/12/2019] [Accepted: 07/13/2019] [Indexed: 11/30/2022] Open
Abstract
In this work, new co- and ter-polymers of methyl methacrylate (MMA), ethyl methacrylate (EMA), and N-butyl methacrylate (nBuMA), containing just 1% mol × mol−1 of a fluorinated co-monomer, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octyl methacrylate (POMA), were synthesized. After an UV accelerated aging test, the photo-chemical stability of the polymers prepared was determined by 1H NMR and FT-IR spectroscopy, size exclusion chromatography, differential scanning calorimetry and wettability measurements. The polymers were applied to Botticino tiles to achieve better performances in terms of water repellency and consequently deterioration resistance. One-year prolonged exposure to a real environment was conducted and the properties of the coated materials and their performances were studied using different surface techniques such as water contact angle (WCA) and colorimetric measurements (CIELaB), capillary absorption, permeability (RVP) tests and soluble salts determination. The effectiveness of the fluorinated methacrylic coatings was clearly demonstrated; among all the resins, the co-polymer MMA_POMA seems to be the most performing one. Furthermore, both the UV photo-chemical resistance and the easiness of removal was successfully studied.
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Affiliation(s)
- Valentina Sabatini
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy.
- Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali (INSTM), Via Giusti 9, 50121 Firenze, Italy.
| | - Eleonora Pargoletti
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali (INSTM), Via Giusti 9, 50121 Firenze, Italy
| | - Valeria Comite
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Marco Aldo Ortenzi
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali (INSTM), Via Giusti 9, 50121 Firenze, Italy
- CRC Materiali Polimerici "LaMPo", Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Paola Fermo
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Davide Gulotta
- The Getty Conservation Institute, 1200 Getty Center Drive, Suite 700, Los Angeles, CA 90049, USA
- Dipartimento di Chimica, Materiali e Ingegneria Chimica "Giulio Natta", Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy
| | - Giuseppe Cappelletti
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- Consorzio Interuniversitario per la Scienza e Tecnologia dei Materiali (INSTM), Via Giusti 9, 50121 Firenze, Italy
- CRC Materiali Polimerici "LaMPo", Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
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10
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Smith LM, Aitken HM, Coote ML. The Fate of the Peroxyl Radical in Autoxidation: How Does Polymer Degradation Really Occur? Acc Chem Res 2018; 51:2006-2013. [PMID: 30016062 DOI: 10.1021/acs.accounts.8b00250] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bolland and Gee's basic autoxidation scheme (BAS) for lipids and rubbers has long been accepted as a general scheme for the autoxidation of all polymers. This scheme describes a chain process of initiation, propagation, and termination to describe the degradation of polymers in the presence of O2. Central to this scheme is the conjecture that propagation of damage to the next polymer chain occurs via hydrogen atom transfer with a peroxyl radical. However, this reaction is strongly thermodynamically disfavored for all but unsaturated polymers, where the product allylic radical is resonance-stabilized. Paradoxically, there is no denying that the autocatalytic degradation and oxidation of saturated polymers still occurs. Critical analysis of the literature, described herein, has begun to unravel this mystery. One possibility is that the BAS still holds for saturated polymers but only at unsaturated defect sites, where H transfer is thermodynamically favorable. Another is that peroxyl termination rather than H transfer is dominant. If this were the case, tertiary peroxyl radicals (formed at quaternary centers or quaternary branching defects) may terminate to form alkoxy radicals, which can much more readily undergo chain transfer. This process would lead to the creation of hydroxy groups on the degraded polymer. On the other hand, primary and secondary peroxyl radicals would terminate to form nonradical products and halt further degradation. As a result, under this scenario the degree of branching and substitution would have a major effect on polymer stability. Herein we survey studies of polymer degradation products and of the effect of polymer structure on stability and show that indeed peroxyl termination is competitive with peroxyl transfer and possibly dominant under some conditions. It is also feasible that oxygen may not be the only reactive atmospheric species involved in catalyzing polymer degradation. Herein we outline plausible mechanisms involving ozone, hydroperoxyl radical, and hydroxyl radical that have all been suggested in the literature and can account for the experimentally observed formation of hydroperoxides without invoking peroxyl transfer. We also show that oxygen itself has even been reported to slow the degradation of poly(methyl methacrylate)s, which might be expected if peroxyl radicals are unreactive toward hydrogen transfer. Discrepancies between the rate of oxidation and the rate of degradation have been observed for polyolefins and also support the counterintuitive notion that oxygen stabilizes these polymers against degradation. We show that together these studies support alternative mechanisms for polymer degradation. A thorough assessment of kinetic studies reported in the literature indicates that they are limited by their propensity to use models based on the BAS, disregarding the chemical differences intrinsic to each class of polymer. Thus, we propose that further work must be done to fully grasp the complex mechanism of polymer degradation under ambient conditions. Nonetheless, our analysis of the literature points to measures that can be used to enhance or prevent polymer degradation and indicates that we should focus beyond just the role of oxygen toward the specific chemical nature and environment of the polymer at hand.
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Affiliation(s)
- Leesa M. Smith
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Heather M. Aitken
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Michelle L. Coote
- ARC Centre of Excellence for Electromaterials Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
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11
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Azo-pigments effect on UV degradation of contemporary art pictorial film: A FTIR-NMR combination study. Polym Degrad Stab 2017. [DOI: 10.1016/j.polymdegradstab.2017.04.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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12
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A comparison study of the degradative effects and safety implications of UVC and 405 nm germicidal light sources for endoscope storage. Polym Degrad Stab 2016. [DOI: 10.1016/j.polymdegradstab.2016.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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13
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Steinbach A, Tautzenberger A, Schaller A, Kalytta-Mewes A, Tränkle S, Ignatius A, Volkmer D. Plasma-enhanced chemical vapor deposition of n-heptane and methyl methacrylate for potential cell alignment applications. ACS APPLIED MATERIALS & INTERFACES 2012; 4:5196-5203. [PMID: 22992135 DOI: 10.1021/am301124b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Plasma-enhanced chemical vapor deposited polymers (plasma polymers) are promising candidates for biomaterials applications. In the present study, plasma deposition as a fast and easily scalable method was adapted to deposit coatings from n-heptane and methyl methacrylate monomers onto glass substrates. Linear patterns with line and groove widths between 1.25 and 160 μm were introduced by degrative UV-lithography for cell alignment. Differential interference contrast optical microscopy, profilometry and atomic force microscopy revealed that the patterned surfaces had a smooth, homogeneous appearance and a pattern height of 8 and 45 nm for plasma deposited n-heptane and methyl methacrylate, respectively. UV-lithography increased the oxygen content on the surface drastically as shown by X-ray photoelectron spectroscopy. After immersion in simulated body fluid for 21 days, the pattern was still intact, and the ester groups were also maintained for the most part as shown by infrared spectroscopy. To test the coatings' potential applicability for biomaterial surfaces in a preliminary experiment, we cultured murine preosteoblastic MC3T3-E1 cells on these coatings. Light and electron microscopically, a normal spindle-shaped and aligned cell morphology was observed. At the mRNA level, cells showed no signs of diminished proliferation or elevated expression of apoptosis markers. In conclusion, plasma-enhanced chemical vapor deposited polymers can be patterned with a fast and feasible method and might be suitable materials to guide cell alignment.
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Affiliation(s)
- Annina Steinbach
- Chair of Solid State Chemistry, Institute of Physics, Universitätstrasse 1, 86159 Augsburg, Germany
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