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Senthooran V, Weng Z, Wu L. Enhancing Mechanical and Thermal Properties of 3D-Printed Samples Using Mica-Epoxy Acrylate Resin Composites-Via Digital Light Processing (DLP). Polymers (Basel) 2024; 16:1148. [PMID: 38675067 PMCID: PMC11054620 DOI: 10.3390/polym16081148] [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: 02/24/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
Digital light processing (DLP) techniques are widely employed in various engineering and design fields, particularly additive manufacturing. Acrylate resins utilized in DLP processes are well known for their versatility, which enables the production of defect-free 3D-printed products with excellent mechanical properties. This study aims to improve the mechanical and thermal properties of 3D-printed samples by incorporating mica as an inorganic filler at different concentrations (5%, 10%, and 15%) and optimizing the dispersion by adding a KH570 silane coupling agent. In this study, mica was introduced as a filler and combined with epoxy acrylate resin to fabricate a 3D-printed sample. Varying concentrations of mica (5%, 10%, and 15% w/w) were mixed with the epoxy acrylate resin at a concentration of 10%, demonstrating a tensile strength increase of 85% and a flexural strength increase of 132%. Additionally, thermal characteristics were analyzed using thermogravimetric analysis (TGA), and successful morphological investigations were conducted using scanning electron microscopy (SEM). Digital light-processing technology was selected for its printing accuracy and cost-effectiveness. The results encompass comprehensive studies of the mechanical, thermal, and morphological aspects that contribute to the advancement of additive manufacturing technology.
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Affiliation(s)
- Velmurugan Senthooran
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (V.S.); (Z.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zixiang Weng
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (V.S.); (Z.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lixin Wu
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (V.S.); (Z.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
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Šimunović L, Jurela A, Sudarević K, Bačić I, Haramina T, Meštrović S. Influence of Post-Processing on the Degree of Conversion and Mechanical Properties of 3D-Printed Polyurethane Aligners. Polymers (Basel) 2023; 16:17. [PMID: 38201683 PMCID: PMC10780983 DOI: 10.3390/polym16010017] [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: 11/30/2023] [Revised: 12/12/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND This study explores how different post-processing methods affect the mechanical properties and degree of conversion of 3d-printed polyurethane aligners made from Tera Harz TC-85 resin. METHODS Using Fourier-transform infrared (FTIR) spectroscopy, the degree of conversion of liquid resin and post-processed materials was analyzed. This investigation focused on the effects of various post-curing environments (nitrogen vs. air) and rinsing protocols (centrifuge, ethanol, isopropanol, and isopropanol + water). The assessed mechanical properties were flexural modulus and hardness. RESULTS The degree of conversion showed no significant variance across different groups, though the polymerization environment influenced the results, accounting for 24.0% of the variance. The flexural modulus varied considerably, depending on both the rinsing protocol and the polymerization environment. The standard protocol (centrifugation followed by nitrogen polymerization) exhibited the highest flexural modulus of 1881.22 MPa. Hardness testing revealed significant differences, with isopropanol treatments showing increased resistance to wear in comparison to the centrifuge and ethanol rinse treatments. CONCLUSIONS This study conclusively demonstrates the adverse effects of oxygen on the polymerization process, underscoring the critical need for an oxygen-free environment to optimize material properties. Notably, the ethanol rinse followed by nitrogen polymerization protocol emerged as a viable alternative to the conventional centrifuge plus nitrogen method.
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Affiliation(s)
- Luka Šimunović
- Department of Orthodontics, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia;
| | - Antonija Jurela
- Dental Clinic Fiziodent, 10000 Zagreb, Croatia; (A.J.); (K.S.)
| | - Karlo Sudarević
- Dental Clinic Fiziodent, 10000 Zagreb, Croatia; (A.J.); (K.S.)
| | - Ivana Bačić
- Forensic Science Centre “Ivan Vučetić”, Ministry of the Interior, 10000 Zagreb, Croatia;
| | - Tatjana Haramina
- Department of Materials, Faculty of Electrical Engineering and Computing, University of Zagreb, 10000 Zagreb, Croatia;
| | - Senka Meštrović
- Department of Orthodontics, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia;
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Bednarczyk P, Walkowiak K, Irska I. Epoxy (Meth)acrylate-Based Thermally and UV Initiated Curable Coating Systems. Polymers (Basel) 2023; 15:4664. [PMID: 38139916 PMCID: PMC10747391 DOI: 10.3390/polym15244664] [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: 11/06/2023] [Revised: 12/07/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Recently, photocurable coatings are being used frequently. However, it is worth mentioning that the use of photopolymerization has its drawbacks, especially in the case of curing coatings on three-dimensional surfaces and in places that are difficult to access for UV radiation. However, it is possible to develop a system in which UV technology and thermal methods for curing coatings can be combined. Moreover, the obtained resins are derived from low-viscosity epoxy resins or diglycidyl ethers, making them an ideal building material for photopolymerization-based three-dimensional printing techniques. Due to the need to improve this method, a series of epoxy (meth)acrylates containing both epoxy and (meth)acrylate groups were obtained via the addition of acrylic or methacrylic acid to epoxy resin, diglycydylether of bisphenol A epoxy resin (DGEBA), cyclohexane dimethanol diglycidyl ether (CHDMDE) and neopentyl glycol diglycidyl ether (NPDE). The structures of the synthesized copolymers were confirmed through spectroscopic analysis (FTIR) and studied regarding their nonvolatile matter content (NV) and acid values (PAVs), as well as their epoxy equivalent values (EEs). Due to the presence of both epoxy and double carbon-carbon pendant groups, two distinct mechanisms can be applied: cationic and radical. Hence, the obtained resins can be cured using UV radiation with thermally appropriate conditions and initiators. This type of method can be used as a solution to many problems currently encountered in using UV technology, such as failure to cure coatings in underexposed areas as well as deformation of coatings. Synthesized epoxy (meth)acrylate prepolymers were employed to formulate photocurable coating compositions. Furthermore, the curing process and properties of cured coatings were investigated regarding some structural factors and parameters. Among the synthesized materials, the most promising are those based on epoxy resin, characterized by their high glass transition temperature values and satisfactory functional properties.
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Affiliation(s)
- Paulina Bednarczyk
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów 42 Avenue, 71-065 Szczecin, Poland
| | - Konrad Walkowiak
- Department of Materials Technology, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology in Szczecin, Piastów 19 Avenue, 70-310 Szczecin, Poland; (K.W.)
| | - Izabela Irska
- Department of Materials Technology, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology in Szczecin, Piastów 19 Avenue, 70-310 Szczecin, Poland; (K.W.)
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Alsaadi M, Hinchy EP, McCarthy CT, Moritz VF, Portela A, Devine DM. Investigation of Thermal, Mechanical and Shape Memory Properties of 3D-Printed Functionally Graded Nanocomposite Materials. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2658. [PMID: 37836299 PMCID: PMC10574263 DOI: 10.3390/nano13192658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/13/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023]
Abstract
In this study, a 3D-printed photocurable resin was developed by incorporating graphene nanoplatelets functionalised with melamine to investigate the thermal, mechanical, fracture and shape memory behaviours. The objective of this work was to produce a printed functionally graded nanocomposite material that has a smart temperature-responsive structure; presents good thermal stability, strength and fracture toughness; and can demonstrate shape-changing motions, such as sequential transformations, over time. The functionalised graphene nanoplatelets were examined via thermogravimetric analysis, Fourier transform infrared spectroscopy, Raman spectroscopy and ultraviolet-visible spectroscopy. Thermogravimetric analysis showed that the degradation temperature of the nanocomposite containing 0.1 wt% of functionalised graphene nanoplatelets at the weight loss of 5% was 304 °C, greater than that of the neat one by 29%. Dynamic mechanical analysis results showed property enhancements of the storage modulus and glass transition temperature. Fracture toughness, tensile strength and impact resistance were improved by 18%, 35% and 78%, respectively. The shape memory tests were performed to obtain the temperature-time recovery behaviour of the 3D-printed structures. The addition of functionalised graphene nanoplatelets demonstrated an enhancement in the shape recovery ratios. Generally, the five subsequent cycles were notably stable with a high recovery ratio of 97-100% for the flat shape and circular shape of the M-GNP specimens. On the other hand, these values were between 91% and 94% for the corresponding neat specimens.
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Affiliation(s)
- Mohamad Alsaadi
- CONFIRM Centre for Smart Manufacturing, University of Limerick, V94 T9PX Limerick, Ireland; (E.P.H.); (C.T.M.)
- PRISM Research Institute, Technological University of the Shannon, Dublin Rd, N37 HD68 Athlone, Ireland (A.P.)
- Materials Engineering Department, University of Technology, Baghdad 10066, Iraq
| | - Eoin P. Hinchy
- CONFIRM Centre for Smart Manufacturing, University of Limerick, V94 T9PX Limerick, Ireland; (E.P.H.); (C.T.M.)
- School of Engineering, University of Limerick, V94 T9PX Limerick, Ireland
| | - Conor T. McCarthy
- CONFIRM Centre for Smart Manufacturing, University of Limerick, V94 T9PX Limerick, Ireland; (E.P.H.); (C.T.M.)
- School of Engineering, University of Limerick, V94 T9PX Limerick, Ireland
| | - Vicente F. Moritz
- PRISM Research Institute, Technological University of the Shannon, Dublin Rd, N37 HD68 Athlone, Ireland (A.P.)
| | - Alexandre Portela
- PRISM Research Institute, Technological University of the Shannon, Dublin Rd, N37 HD68 Athlone, Ireland (A.P.)
| | - Declan M. Devine
- PRISM Research Institute, Technological University of the Shannon, Dublin Rd, N37 HD68 Athlone, Ireland (A.P.)
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Wu L, Zhu W, Li Z, Li H, Xu J, Li S, Chen M. Urushiol modified epoxy acrylate as UV spray painting oriental lacquer ink. RSC Adv 2023; 13:1106-1114. [PMID: 36686956 PMCID: PMC9811650 DOI: 10.1039/d2ra06685h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 12/23/2022] [Indexed: 01/05/2023] Open
Abstract
As a natural "water-based" polymer composite material, oriental lacquer is often referred to as the "king of coatings" and is used as a coating in the defense industry, chemical industry, petroleum industry, metallurgy and mining industry, textile painting and dyeing industry, pharmaceutical industry, as well as the protection of ancient buildings and cultural relics. However, the development of modern industrialization is greatly hindered by the high viscosity of oriental lacquer, the difficulty of spraying, the long drying cycle, and the seriousness of allergenicity. Herein, based on the principle of oriental lacquer and the characteristics of prepolymer in ink, we developed a new prepolymer for modulating UV oriental lacquer ink and explored the feasibility of using it as a raw material for UV spray painting. In this study, lacquer phenol was extracted from oriental lacquer and modified with epoxy acrylate by a simple mechanical compounding method to obtain lacquer epoxy acrylate. Moreover, the UV spray painting oriental lacquer ink was also prepared by using it as the main film-forming substance. The orthogonal experiment method was used to optimize the best formulation of UV spray painting oriental lacquer ink by using nozzle passability, viscosity and curing time as test indexes. Meanwhile, the film properties of UV spray painting oriental lacquer inks were also evaluated. The test results show that the UV spray painting oriental lacquer ink prepared with urushiol epoxy acrylate has better dispersion, excellent paint film performance, and solves the problem that oriental lacquer cannot be printed. This present work shows that urushiol epoxy acrylate as a new type of prepolymer has broad application prospects in the actual preparation of UV inks.
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Affiliation(s)
- Lujing Wu
- Academy of Art, Jinling Institute of Technology Nanjing 211199 China
| | - Wenkai Zhu
- College of Chemistry and Materials Engineering, Zhejiang A & F University Hangzhou 311300 China
| | - Zequn Li
- College of Chemistry and Materials Engineering, Zhejiang A & F University Hangzhou 311300 China
| | - Huimin Li
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University Nanjing 210037 China
| | - Jing Xu
- Academy of Art, Jinling Institute of Technology Nanjing 211199 China
| | - Song Li
- College of Chemistry and Materials Engineering, Zhejiang A & F University Hangzhou 311300 China
| | - Meiling Chen
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University Nanjing 210037 China
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Bednarczyk P, Irska I, Gziut K, Mozelewska K, Ossowicz-Rupniewska P. Synthesis of Hybrid Epoxy Methacrylate Resin Based on Diglycidyl Ethers and Coatings Preparation via Cationic and Free-Radical Photopolymerization. Int J Mol Sci 2022; 23:ijms232415592. [PMID: 36555232 PMCID: PMC9779419 DOI: 10.3390/ijms232415592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/30/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
A series of difunctional epoxy methacrylate resins (EAs) containing at least one epoxy and at least one methacrylate group were synthesized by means of an addition reaction between epoxy-terminated diglycidyl ethers and methacrylic acid. In order to investigate the impact of polymer architecture on the course of addition reactions and further coating properties, several different types of diglycidyl ethers, i.e., linear, containing aliphatic or aromatic rings, with a short or polymeric backbone, were employed in the synthesis. The carboxyl-epoxide addition esterification reactions have been found to, in a relatively straightforward manner, control the extent of acrylation depending on the substrate feed ratio and reaction time. The structure of obtained pre-polymers was evaluated by FT-IR and NMR methods. At the same time, the extent of addition reactions was validated via quantitative analysis, including non-volatile matter content (NV), acid value (PAVs), and epoxy equivalent value (EE) analysis. The modification was carried out in a manner likely to create a compound with one epoxy and one carbon-carbon pendant group. Hence, due to the presence of both functionalities, it is possible to crosslink compositions based on synthesized EAs via two distinct mechanisms: (i) cationic polymerization or (ii) free-radical polymerization. Synthesized epoxy methacrylate pre-polymers were further employed for use in formulate photocurable coating compositions by the cationic or radical process. Furthermore, the photopolymerization behavior and properties of cured coatings were explored regarding some structural factors and parameters. The investigated polymeric materials cure in a short time to obtain coatings with good properties, which is why they can be successfully used to produce protective and decorative coatings for many industries.
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Affiliation(s)
- Paulina Bednarczyk
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Ave. 42, 71-065 Szczecin, Poland
- Correspondence:
| | - Izabela Irska
- Department of Materials Technology, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology in Szczecin, Piastów 19 Avenue, 70-310 Szczecin, Poland
| | - Konrad Gziut
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Ave. 42, 71-065 Szczecin, Poland
| | - Karolina Mozelewska
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Ave. 42, 71-065 Szczecin, Poland
| | - Paula Ossowicz-Rupniewska
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastów Ave. 42, 71-065 Szczecin, Poland
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Borges FDS, Moraes FJH, Pereira Neto MA, d'Almeida JRM, Bento AC, Cella N. Photoacoustic spectroscopy applied in the monitoring of photocuring process in epoxy diacrylate resins: Positive effect. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Francis de Souza Borges
- Instituto Politécnico, IPRJ Universidade do Estado do Rio de Janeiro, UERJ Nova Friburgo RJ Brazil
| | | | | | - José Roberto Moraes d'Almeida
- Departamento de Engenharia Química e de Materiais Pontifícia Universidade Católica do Rio de Janeiro, PUC‐Rio Rio de Janeiro RJ Brazil
| | | | - Norberto Cella
- Instituto Politécnico, IPRJ Universidade do Estado do Rio de Janeiro, UERJ Nova Friburgo RJ Brazil
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Preparation and characterization of UV-cured epoxy acrylate-based nanocomposite coatings containing organonanoclay. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04386-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mozelewska K, Czech Z, Bartkowiak M, Nowak M, Bednarczyk P, Niezgoda P, Kabatc J, Skotnicka A. Preparation and Characterization of Acrylic Pressure-Sensitive Adhesives Crosslinked with UV Radiation-Influence of Monomer Composition on Adhesive Properties. MATERIALS (BASEL, SWITZERLAND) 2021; 15:246. [PMID: 35009393 PMCID: PMC8745841 DOI: 10.3390/ma15010246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 06/02/2023]
Abstract
In this study, syntheses of acrylate copolymers were performed based on the monomers butyl acrylate (BA), 2-ethylhexyl acrylate (2-EHA), and acrylic acid (AA) and the second-type unsaturated photoinitiator 4-acryloyloxybenzophenone (ABP). The structure of the obtained copolymers was confirmed via FT-IR spectroscopic analysis, and the viscosity and the content of non-volatile substances were determined. The adhesive films were then coated and cross-linked using ultraviolet radiation in the UV-C range at various doses (5-50 mJ/cm2). Due to the dependence of the self-adhesive properties of the adhesive layer on the basis weight, various basis weights of the layer in the range of 30-120 g/m2 were tested. Finally, the self-adhesive properties were assessed: tack, peel adhesion, shear strength (cohesion) at 20 °C and 70 °C, as well as the SAFT test and shrinkage. The aim of the study was to determine the effect of the type of monomer used, the dose of ultraviolet radiation, and the basis weight on the self-adhesive and usable properties of the obtained self-adhesive tapes.
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Affiliation(s)
- Karolina Mozelewska
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastow Ave. 42, 71-065 Szczecin, Poland; (Z.C.); (M.B.); (M.N.); (P.B.)
| | - Zbigniew Czech
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastow Ave. 42, 71-065 Szczecin, Poland; (Z.C.); (M.B.); (M.N.); (P.B.)
| | - Marcin Bartkowiak
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastow Ave. 42, 71-065 Szczecin, Poland; (Z.C.); (M.B.); (M.N.); (P.B.)
| | - Małgorzata Nowak
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastow Ave. 42, 71-065 Szczecin, Poland; (Z.C.); (M.B.); (M.N.); (P.B.)
| | - Paulina Bednarczyk
- Department of Chemical Organic Technology and Polymeric Materials, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Piastow Ave. 42, 71-065 Szczecin, Poland; (Z.C.); (M.B.); (M.N.); (P.B.)
| | - Piotr Niezgoda
- Plant Protection Laboratory, Faculty of Environmental Management and Agriculture, West Pomeranian University of Technology in Szczecin, Piastów Ave. 42, 71-065 Szczecin, Poland;
| | - Janina Kabatc
- Department of Organic Chemistry, Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, Seminaryjna 3, 85-326 Bydgoszcz, Poland; (J.K.); (A.S.)
| | - Agnieszka Skotnicka
- Department of Organic Chemistry, Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, Seminaryjna 3, 85-326 Bydgoszcz, Poland; (J.K.); (A.S.)
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Synthesis of Epoxy Methacrylate Resin and Coatings Preparation by Cationic and Radical Photocrosslinking. Molecules 2021; 26:molecules26247663. [PMID: 34946745 PMCID: PMC8706006 DOI: 10.3390/molecules26247663] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/04/2022] Open
Abstract
This work involves the synthesis of hybrid oligomers based on the epoxy methacrylate resin. The EA resin was obtained by the modification of industrial-grade bisphenol A-based epoxy resin and methacrylic acid has been synthesized in order to develop multifunctional resins comprising both epoxide group and reactive, terminal unsaturation. Owing to the presence of both epoxy and double carbon–carbon pendant groups, the reaction product exhibits photocrosslinking via two distinct mechanisms: (i) cationic ring-opening polymerization and (ii) free radical polymerization. Monitoring of EA synthesis reactions over time using PAVs, MAAC and NV parameters, and the FT-IR method reveals that esterification reactions proceed faster at the start, exhibiting over 40% of conversion within the initial 60 min, which can be associated with a relatively high concentration of reactive sites and low viscosity of the reaction mixture at the initial reaction stage. With the further increase in the reaction time, the reaction rate tends to decrease. The control of the EA synthesis process can guide how to adjust reactions to obtain EAs with desired characteristics. Based on obtained values, one can state that the optimum synthesis time of about 4–5 h should be adopted to prepare EAs having both epoxy groups and unsaturated double bonds. The structure of the obtained EA was confirmed by FT-IR and NMR methods, as well as the determination of partial acid value and epoxy equivalent. Samples at various stages of synthesis were cured with UV radiation in order to study the kinetics of the process according to cationic and radical polymerization determined via photo-differential scanning calorimetry (photo-DSC) and real-time infrared spectroscopy (RT-IR) and then the properties of the cured coatings were tested. It turned out that the cationic polymerization was slower with a lower conversion of the photoreactive groups, as compared to the radical polymerization. All the obtained EA coatings were characterized by good properties of cured coatings and can be successfully used in the coating-forming sector.
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