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Ferreres G, Pérez-Rafael S, Morena AG, Tzanov T, Gryshchuk L. Influence of Enzymatically Hydrophobized Hemp Protein on Morphology and Mechanical Properties of Bio-Based Polyurethane and Epoxy Foams. Polymers (Basel) 2023; 15:3608. [PMID: 37688234 PMCID: PMC10490182 DOI: 10.3390/polym15173608] [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: 08/07/2023] [Revised: 08/26/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
Biomass fillers offer the possibility to modify the mechanical properties of foams, increasing their cost-effectiveness and reducing their carbon footprint. In this study, bio-based PU (soft, open cells for the automotive sector) and epoxy (EP, hard, closed cells for construction applications) composite foams were prepared by adding pristine and laccase-mediated lauryl gallate-hydrophobized hemp protein particles as filler (HP and HHP, respectively). The fillers were able to modify the density, the mechanical properties and the morphology of the PU and EP foams. The addition of HP filler increases the density of PU foams up to 100% and significantly increases the σ values by 40% and Emod values. On the other hand, the inclusion of the HHP as filler in PU foams mostly results in reduced density, by almost 30%, and reduced σ values in comparison with reference and HP-filled foams. Independently from filler concentration and type, the biomass increased the Emod values for all foams relative to the reference. In the case of the EP foams, the tests were only conducted for the foams filled with HHP due to the poor compatibility of HP with the EP matrix. HHP decreased the density, compressive strength and Emod values of the composites. For both foams, the fillers increased the size of the cells, while reducing the amount of open cells of PU foams and the amount of closed cells for EP foams. Finally, both types of foams filled with HHP reduced the moisture uptake by 80 and 45%, respectively, indicating the successful hydrophobization of the composites.
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Affiliation(s)
- Guillem Ferreres
- Grup de Biotecnologia Molecular i Industrial, Universitat Politècnica de Catalunya, Edifici Gaia, TR14, Rambla Sant Nebridi, 22, 08222 Terrassa, Spain; (G.F.); (S.P.-R.); (A.G.M.); (T.T.)
| | - Sílvia Pérez-Rafael
- Grup de Biotecnologia Molecular i Industrial, Universitat Politècnica de Catalunya, Edifici Gaia, TR14, Rambla Sant Nebridi, 22, 08222 Terrassa, Spain; (G.F.); (S.P.-R.); (A.G.M.); (T.T.)
| | - Angela Gala Morena
- Grup de Biotecnologia Molecular i Industrial, Universitat Politècnica de Catalunya, Edifici Gaia, TR14, Rambla Sant Nebridi, 22, 08222 Terrassa, Spain; (G.F.); (S.P.-R.); (A.G.M.); (T.T.)
| | - Tzanko Tzanov
- Grup de Biotecnologia Molecular i Industrial, Universitat Politècnica de Catalunya, Edifici Gaia, TR14, Rambla Sant Nebridi, 22, 08222 Terrassa, Spain; (G.F.); (S.P.-R.); (A.G.M.); (T.T.)
| | - Liudmyla Gryshchuk
- Leibniz-Institut für Verbundwerkstoffe GmbH, Erwin-Schrödinger-Straße 58, 67663 Kaiserslautern, Germany
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Irven G, Carolan D, Fergusson A, Dear JP. Fracture performance of epoxy foam: Low density to bulk polymer. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125420] [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]
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Xu Z, Zhang Y, Wu Y, Lu X. Spectroscopically Detecting Molecular-Level Bonding Formation between an Epoxy Formula and Steel. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13261-13271. [PMID: 36254887 DOI: 10.1021/acs.langmuir.2c02325] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The formation of the interfacial adhesion between an epoxy adhesive and a substrate was normally accompanied by the epoxy curing process on the substrate. Although the debate on the formation mechanism of the interfacial adhesion is still ongoing, this issue can causally be resolved by studying the interfacial structural formation between the epoxy adhesive and the substrate. Herein, to reveal the interfacial structural formation of a representative formula composed of epoxy (digylcidyl ether of biphenyl A, DGEBA) and amine hardener (2,2'-(ethylenedioxy) diethylamine, EDDA) with the steel substrate upon curing and postcuring treatments, sum-frequency generation (SFG) vibrational spectroscopy with a sandwiched transparent window/epoxy adhesive/steel setup was applied to detect and track the buried molecular-level structures at the epoxy adhesive/steel interface. An X-ray photoelectron spectroscopic (XPS) experiment was performed to probe the intentionally exposed interface to disclose the occurring interfacial chemical reaction. The reaction between the epoxy groups and the steel-surface OH groups and the molecular reconstruction of interfacial epoxy methyl groups upon curing and postcuring steps were confirmed. The latter also indirectly indicated the formation of the additional hydrogen bonding and the former bonding reaction at the interface. The above two spectroscopic experimental results matched up with the further examination of the adhesion strength. Therefore, this work elucidates the formation of the interfacial bonding between the epoxy formula and the steel substrate upon curing and postcuring treatments at the molecular level, thus providing an in-depth insight into the origin of the interfacial adhesion.
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Affiliation(s)
- Zhaohui Xu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing210096, China
| | - Yinyu Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang621900, China
| | - Yeping Wu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang621900, China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing210096, China
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Uy Lan DN, Bethke C, Altstädt V, Ruckdäschel H. Preparation of pros-foam sheets and their epoxy foams using the solid-state carbamate-foaming technique. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Xu Z, Zhang Y, Wu Y, Lu X. Molecular-Level Correlation between Spectral Evidence and Interfacial Bonding Formation for Epoxy Adhesives on Solid Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5847-5856. [PMID: 35441517 DOI: 10.1021/acs.langmuir.2c00470] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Interfacial bonding strength of an epoxy-based adhesive depends on the interfacial interaction between the adhesive and the substrate. Normally, the curing process at the interface accompanied by the interfacial bonding formation is different from that in the bulk, and it is still a big challenge to probe the interfacial bonding formation at a molecular level. In this study, to trace the interfacial structural evolution of a representative formula of epoxy (digylcidyl ether of biphenyl A, DGEBA) and amine hardener [1,2-bis(2-aminoethoxy)ethane, EDDA] with the sapphire and silica substrates upon curing and post-curing steps, sum frequency generation (SFG) vibrational spectroscopy is employed to detect the molecular-level interfacial structural information. For the sapphire substrate, upon curing, backbone methylene (CH2) stretching signals decrease, indicating the formation of a rigid chain network structure and thus losing the local methylene order, while vibrational signals of the sapphire surface hydroxyl (OH) groups (including hydrogen-bonded and unbonded) increase significantly, indicating the formation of a strong hydrogen-bonding and polar interaction between the epoxy adhesive and the sapphire surface. Upon post-curing, increased backbone CH2 signals and decreased sapphire OH signals suggest interfacial chemical bonding formation due to the reaction between the epoxy rings and the sapphire surface OH groups. Orientation analysis confirms the enhanced ordering of the sapphire surface OH groups upon curing and post-curing, in comparison to the uncured epoxy formula. As for the fused silica, weak vibrational signals of the methylene (CH2) and methyl (CH3) groups are observed before curing, while both of them increase slightly for the cured and post-cured epoxy formulae, suggesting relatively less hydrophilic nature of the silica surface compared to that of the sapphire surface, also evidenced by the very weak OH signals upon curing and post-curing. Further measurement on the adhesion strength matches up with the above spectroscopic experimental results, substantiating the correlation between the macroscopic bonding strength of the epoxy adhesive and the microscopic molecular-level structure.
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Affiliation(s)
- Zhaohui Xu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Yinyu Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Yeping Wu
- Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, China
| | - Xiaolin Lu
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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Steindl P, Decker H, Retzl B, Jiang Q, Menner A, Bismarck A. Emulsion-templated flexible epoxy foams. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Sun X, Wang Y, Tang Y, Zhang B, Wei W, Li X, Fei X, Liu X. Synthesis of isocyanurate‐based imidazole carboxylate as thermal latent curing accelerator for thermosetting epoxy resins. J Appl Polym Sci 2020. [DOI: 10.1002/app.49221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Xin Sun
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material EngineeringJiangnan University Wuxi Jiangsu China
| | - Yiming Wang
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material EngineeringJiangnan University Wuxi Jiangsu China
| | - Yuyao Tang
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material EngineeringJiangnan University Wuxi Jiangsu China
| | - Bowen Zhang
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material EngineeringJiangnan University Wuxi Jiangsu China
| | - Wei Wei
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material EngineeringJiangnan University Wuxi Jiangsu China
| | - Xiaojie Li
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material EngineeringJiangnan University Wuxi Jiangsu China
| | - Xiaoma Fei
- Wuxi Chuangda Advanced Materials Co., Ltd. Wuxi Jiangsu China
| | - Xiaoya Liu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material EngineeringJiangnan University Wuxi Jiangsu China
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Song W, Magid A, Li D, Lee KY. Application of recycled carbon-fibre-reinforced polymers as reinforcement for epoxy foams. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 269:110766. [PMID: 32560991 DOI: 10.1016/j.jenvman.2020.110766] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 05/06/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
The ever-increasing demand for carbon fibre reinforced polymers (CFRP) and stringent environmental legislation have driven the research into recycling and reusing the CFRP waste. This paper presents a mechanical recycling process of CFRP and the application of the recyclates as reinforcement for epoxy foams. The CFRP was mechanically processed using a jet mill. Up to 10 wt% of the CFRP recyclates, without separation of fibre-rich portion and resin-rich portion, was added into epoxy foams. The compressive modulus and strength of the epoxy foams increased from 288 MPa and 7.0 MPa, respectively, to 1060 MPa and 22.8 MPa, respectively, accompanied with an increase in foam density from 0.37 g cm-3 to 0.68 g cm-3. Consequently, the specific compressive modulus and strength (normalised against density) increased from 789 MPa cm3 g-1 and 19.1 MPa cm3 g-1 for unreinforced foam to 1563 MPa cm3 g-1 and 33.5 MPa cm3 g-1 for CFRP recyclates reinforced foam, representing a 98% and 75% improvement, respectively. These results demonstrate that the CFRP recyclates have excellent reinforcing ability for epoxy foams.
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Affiliation(s)
- Wenzhe Song
- Department of Aeronautics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
| | - Ahmed Magid
- Department of Aeronautics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Diyang Li
- Department of Aeronautics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Koon-Yang Lee
- Department of Aeronautics, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
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