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Li Y, Jiang J, Huang H, Wang Z, Wang L, Chen B, Zhai W. Comparative Study of the Foaming Behavior of Ethylene-Vinyl Acetate Copolymer Foams Fabricated Using Chemical and Physical Foaming Processes. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3719. [PMID: 39124388 PMCID: PMC11313140 DOI: 10.3390/ma17153719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2024] [Revised: 07/22/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024]
Abstract
Ethylene-vinyl acetate copolymer (EVA), a crucial elastomeric resin, finds extensive application in the footwear industry. Conventional chemical foaming agents, including azodicarbonamide and 4,4'-oxybis(benzenesulfonyl hydrazide), have been identified as environmentally problematic. Hence, this study explores the potential of physical foaming of EVA using supercritical nitrogen as a sustainable alternative, garnering considerable interest in both academia and industry. The EVA formulations and processing parameters were optimized and EVA foams with densities between 0.15 and 0.25 g/cm3 were produced. Key findings demonstrate that physical foaming not only reduces environmental impact but also enhances product quality by a uniform cell structure with small cell size (50-100 μm), a wide foaming temperature window (120-180 °C), and lower energy consumption. The research further elucidates the mechanisms of cell nucleation and growth within the crosslinked EVA network, highlighting the critical role of blowing agent dispersion and localized crosslinking around nucleated cells in defining the foam's cellular morphology. These findings offer valuable insights for producing EVA foams with a more controllable cellular structure, utilizing physical foaming techniques.
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Affiliation(s)
| | - Junjie Jiang
- School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; (Y.L.); (H.H.); (Z.W.); (L.W.); (B.C.)
| | | | | | | | | | - Wentao Zhai
- School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; (Y.L.); (H.H.); (Z.W.); (L.W.); (B.C.)
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2
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Kim KH, Kim JH, Lim DH, Kwon BC, Hong J, Yoon HS, Cha SW. In Situ Changes in Mechanical Properties Based on Gas Saturation Inside Pressure Vessels. Polymers (Basel) 2024; 16:1276. [PMID: 38732744 PMCID: PMC11085073 DOI: 10.3390/polym16091276] [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: 04/08/2024] [Revised: 04/25/2024] [Accepted: 04/28/2024] [Indexed: 05/13/2024] Open
Abstract
In previous studies, difficulties were encountered in measuring changes within high-pressure vessels owing to limitations such as sensor connectors and sensor failures under high-pressure conditions. In addition, polymer-gas mixtures experience instantaneous gas desorption upon exiting high-pressure vessels owing to pressure differentials, leading to measurement errors. In this study, a device using magnetic sensors was developed to measure the real-time changes in gas-saturated polymers inside pressure vessels. Experiments on polymethyl methacrylate gas adsorption were conducted with parameters including pressure at 5 MPa and temperatures ranging from -20 to 40 °C for 60 and 180 min. It was observed that at -20 °C, the maximum magnetic field force density and deflection were 391.53 μT and 5.83 mm, respectively, whereas at 40 °C, deflection did not occur, with a value of 321.79 μT. Based on gas saturation experiments, a new model for deflection in high-pressure atmospheres is proposed. Additionally, an ANSYS analysis was conducted to predict the changes in Young's modulus based on gas saturation. In previous studies, mechanical properties were measured outside the pressure vessel, resulting in an error due to a pressure difference, while the proposed method is characterized by the ability to directly measure polymer behavior according to gas saturation in high-pressure vessels using a magnetic sensor in real time. Therefore, it is possible to predict polymer behavior, making it easy to control variables in high-pressure polymer processes.
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Affiliation(s)
- Kwan Hoon Kim
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Jae Hoo Kim
- Convergence Research Center for Solutions to Electromagnetic Interference in Future-Mobility, Korea Institute of Science and Technology (KIST), 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea;
| | - Dong Hwan Lim
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Byung Chul Kwon
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Jin Hong
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Ho Sub Yoon
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
| | - Sung Woon Cha
- School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemoon-gu, Seoul 03722, Republic of Korea; (K.H.K.); (D.H.L.); (B.C.K.); (J.H.); (H.S.Y.)
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3
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Schaible T, Bonten C. Prediction of the Bubble Growth Behavior by Means of the Time-, Temperature-, Pressure- and Blowing Agent Concentration-Dependent Transient Elongational Viscosity Function of Polymers. Polymers (Basel) 2024; 16:1213. [PMID: 38732682 PMCID: PMC11085101 DOI: 10.3390/polym16091213] [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: 04/05/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Bubble growth processes are highly complex processes, which are not only dependent on the foaming process parameters (temperature, pressure and blowing agent concentration) but also on the type and structure of the polymer used. Since the elongational viscosity at the bubble wall during bubble growth also depends on these influencing factors, the so-called transient elongational viscosity plays a key role in describing the gas bubble growth behavior in polymer melts. The model-based description of the transient elongational viscosity function is difficult due to its dependence on time, Hencky strain and strain rate. Therefore, representative viscosities or shear viscosity models are usually used in the literature to predict the bubble growth behavior. In this work, the transient equibiaxial elongational viscosity function at the bubble wall during bubble growth is described holistically for the first time. This is achieved by extending the so-called molecular stress function (MSF) model by superposition principles (temperature, pressure and blowing agent concentration) and by using the elongational deformation behavior (Hencky strain and strain rate) at the bubble wall during the initial, and thus viscosity-driven, bubble growth process. Therefore, transient uniaxial elongational viscosity measurements are performed and the non-linear MSF model parameters of the two investigated polymers PS (linear polymer chains) and PLA (long-chain branched polymer chains) are determined. By applying the superposition principles and by changing the strain mode parameter to the equibiaxial case in the MSF model, the transient equibiaxial viscosity master curve is obtained and used to describe the bubble growth process. The results show that the extended MSF model can fully predict the transient equibiaxial elongational viscosity function at the bubble wall during bubble growth processes. The bubble growth behavior over time can then be realistically described using the defined transient equibiaxial elongational viscosity function at the bubble wall. This is not possible, for example, with a representative viscosity and therefore clearly demonstrates the influence and importance of knowing the transient deformation behavior that prevails at the bubble wall during bubble growth processes.
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Affiliation(s)
- Tobias Schaible
- Institut für Kunststofftechnik, University of Stuttgart, Pfaffenwaldring 32, 70569 Stuttgart, Germany;
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Kontos G, Tsioptsias C, Tsivintzelis I. Cellulose Acetate-Ionic Liquid Blends as Potential Polymers for Efficient CO 2 Separation Membranes. Polymers (Basel) 2024; 16:554. [PMID: 38399932 PMCID: PMC10891773 DOI: 10.3390/polym16040554] [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: 01/26/2024] [Revised: 02/15/2024] [Accepted: 02/17/2024] [Indexed: 02/25/2024] Open
Abstract
CO2 capture, applied in CO2 separation from natural gas or in CO2/N2 separation from power plant flue gas streams, is of great importance for technical, economic, and environmental reasons. The latter seems important because CO2, as a greenhouse gas, is considered the main contributor to global warming. Using polymeric membranes for CO2 separation presents several advantages, such as low energy demand, small equipment volume, and the absence of liquid waste. In this study, two ionic liquids (ILs) were used for the preparation of cellulose acetate (CA)-IL blend membranes for potential CO2 capture applications, namely, 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim+][HSO4-]) and choline glycine ([Ch+]Gly-), as they present adequate CO2 dissolution ability. The first IL is commercially available, whereas the latter was synthesized by a novel route. Several composite membranes were prepared through the solvent casting technique and characterized by a variety of methods, including thermogravimetry, calorimetry, FTIR spectroscopy, and X-ray diffraction. The CO2 sorption in the composite membranes was experimentally measured using the mass loss analysis (MLA) technique. The results showed that the ILs strongly interacted with the C=O groups of CA, which exhibited high affinity with CO2. In the case of [Bmim+][HSO4-], a reduction in the available sites that allow strong intermolecular interactions with CO2 resulted in a decrease in CO2 sorption compared to that of pure CA. In the case of [Ch+]Gly-, the reduction was balanced out by the presence of specific groups in the IL, which presented high affinity with CO2. Thus, the CA-[Ch+]Gly- blend membranes exhibited increased CO2 sorption capability, in addition to other advantages such as non-toxicity and low cost.
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Affiliation(s)
- Giannis Kontos
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Costas Tsioptsias
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
- Department of Chemical Engineering, University of Western Macedonia, 50132 Kozani, Greece
| | - Ioannis Tsivintzelis
- Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
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Amiri-Ramsheh B, Nait Amar M, Shateri M, Hemmati-Sarapardeh A. On the evaluation of the carbon dioxide solubility in polymers using gene expression programming. Sci Rep 2023; 13:12505. [PMID: 37532745 PMCID: PMC10397320 DOI: 10.1038/s41598-023-39343-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 07/24/2023] [Indexed: 08/04/2023] Open
Abstract
Evaluation, prediction, and measurement of carbon dioxide (CO2) solubility in different polymers are crucial for engineers in various chemical applications, such as extraction and generation of novel materials. In this paper, correlations based on gene expression programming (GEP) were generated to predict the value of carbon dioxide solubility in three polymers. Results showed that the generated correlations could represent an outstanding efficiency and provide predictions for carbon dioxide solubility with satisfactory average absolute relative errors of 9.71%, 5.87%, and 1.63% for polystyrene (PS), polybutylene succinate-co-adipate (PBSA), and polybutylene succinate (PBS), respectively. Trend analysis based on Henry's law illustrated that increasing pressure and decreasing temperature lead to an increase in carbon dioxide solubility. Finally, outlier discovery was applied using the leverage approach to detect the suspected data points. The outlier detection demonstrated the statistical validity of the developed correlations. William's plot of three generated correlations showed that all of the data points are located in the valid zone except one point for PBS polymer and three points for PS polymer.
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Affiliation(s)
- Behnam Amiri-Ramsheh
- Department of Petroleum Engineering, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Menad Nait Amar
- Département Etudes Thermodynamiques, Division Laboratoires, Sonatrach, Boumerdes, Algeria
| | - Mohammadhadi Shateri
- Department of System Engineering, École de Technologie Supérieur, Montreal, QC, Canada.
| | - Abdolhossein Hemmati-Sarapardeh
- Department of Petroleum Engineering, Shahid Bahonar University of Kerman, Kerman, Iran.
- State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing, China.
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Production and Application of Polymer Foams Employing Supercritical Carbon Dioxide. ADVANCES IN POLYMER TECHNOLOGY 2022. [DOI: 10.1155/2022/8905115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Polymeric foams have characteristics that make them attractive for different applications. However, some foaming methods rely on chemicals that are not environmentally friendly. One of the possibilities to tackle the environmental issue is to utilize supercritical carbon dioxide ScCO2 since it is a “green” solvent, thus facilitating a sustainable method of producing foams. ScCO2 is nontoxic, chemically inert, and soluble in molten plastic. It can act as a plasticizer, decreasing the viscosity of polymers according to temperature and pressure. Most foam processes can benefit from ScCO2 since the methods rely on nucleation, growth, and expansion mechanisms. Process considerations such as pretreatment, temperature, pressure, pressure drop, and diffusion time are relevant parameters for foaming. Other variables such as additives, fillers, and chain extenders also play a role in the foaming process. This review highlights the morphology, performance, and features of the foam produced with ScCO2, considering relevant aspects of replacing or introducing a novel foam. Recent findings related to foaming assisted by ScCO2 and how processing parameters influence the foam product are addressed. In addition, we discuss possible applications where foams have significant benefits. This review shows the recent progress and possibilities of ScCO2 in processing polymer foams.
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Herczeg CK, Song J. Sterilization of Polymeric Implants: Challenges and Opportunities. ACS APPLIED BIO MATERIALS 2022; 5:5077-5088. [PMID: 36318175 PMCID: PMC9691608 DOI: 10.1021/acsabm.2c00793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Degradable and environmentally responsive polymers have been actively developed for drug delivery and regenerative medicine applications, yet inadequate consideration of their compatibility with terminal sterilization presents notable barriers to clinical translation. This Review discusses industry-established terminal sterilization methods and aseptic processing and contrasts them with innovative approaches aimed at preserving the integrity of polymeric implants. Regulatory guidelines, fiscal considerations, and potential pitfalls are discussed to encourage early integration of sterility regulatory considerations in material designs.
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Affiliation(s)
- Chloe K Herczeg
- Department of Orthopedics and Physical Rehabilitation, Department of Biochemistry and Molecular Biotechnology, UMass Chan Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, United States
| | - Jie Song
- Department of Orthopedics and Physical Rehabilitation, Department of Biochemistry and Molecular Biotechnology, UMass Chan Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, United States
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Rangappa R, Yeh SK. Effect of N2 plasticization on the crystallization of different hardnesses of thermoplastic polyurethanes. J Supercrit Fluids 2022. [DOI: 10.1016/j.supflu.2022.105726] [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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9
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Supercritical CO2-assisted Impregnation/Deposition of Polymeric Materials With Pharmaceutical, Nutraceutical, and Biomedical Applications: A Review (2015-2021). J Supercrit Fluids 2022. [DOI: 10.1016/j.supflu.2022.105763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Taki K, Menale M, Pisante G, Di Maio E. A design tool for core‐back timing in foam injection molding. J Appl Polym Sci 2022. [DOI: 10.1002/app.53121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kentaro Taki
- School of Mechanical Engineering, College of Science and Engineering Kanazawa University Kanazawa Japan
| | - Marco Menale
- Department of Mathematics and Physics University of Campania "Luigi Vanvitelli" Caserta Italy
| | - Giovanni Pisante
- Department of Mathematics and Physics University of Campania "Luigi Vanvitelli" Caserta Italy
| | - Ernesto Di Maio
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale University of Naples Federico II Naples Italy
- Foamlab University of Naples Federico II Naples Italy
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Jiang J, Zhou M, Li Y, Chen B, Tian F, Zhai W. Cell structure and hardness evolutions of TPU foamed sheets with high hardness via a temperature rising foaming process. J Supercrit Fluids 2022. [DOI: 10.1016/j.supflu.2022.105654] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Wang L, Chi W, Liu C, Fan J, Lin J, Liu Y. Large‐scalable polar bear hair‐like cellular hollow fibers with excellent thermal insulation and ductility. J Appl Polym Sci 2022. [DOI: 10.1002/app.53018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Liang Wang
- School of Textiles Science and Engineering Tiangong University Tianjin People's Republic of China
| | - Weili Chi
- School of Textiles Science and Engineering Tiangong University Tianjin People's Republic of China
| | - Chuanyong Liu
- School of Textiles Science and Engineering Tiangong University Tianjin People's Republic of China
| | - Jie Fan
- School of Textiles Science and Engineering Tiangong University Tianjin People's Republic of China
| | - Jinyou Lin
- Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai People's Republic of China
| | - Yong Liu
- School of Textiles Science and Engineering Tiangong University Tianjin People's Republic of China
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Screening of the Supercritical Impregnation of Olea europaea Leaves Extract into Filaments of Thermoplastic Polyurethane (TPU) and Polylactic Acid (PLA) Intended for Biomedical Applications. Antioxidants (Basel) 2022; 11:antiox11061170. [PMID: 35740066 PMCID: PMC9219857 DOI: 10.3390/antiox11061170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/04/2022] [Accepted: 06/10/2022] [Indexed: 11/16/2022] Open
Abstract
The leaves of Olea europaea as agricultural waste represent a convenient source of antioxidants. In combination with supercritical CO2 (scCO2), assisted impregnation is an interesting strategy for the preparation of biomedical devices with specific bioactivity. For this purpose, 3D-printable filaments of thermoplastic polyurethane (TPU) and polylactic acid (PLA) were employed for the supercritical impregnation of ethanolic olive leaves extract (OLE) for biomedical application. The extraction of OLE was performed using pressurized liquids. The effect of pressure (100-400 bar), temperature (35-55 °C), and the polymer type on the OLE impregnation and the swelling degree were studied including a morphological analysis and the measurement of the final antioxidant activity. All the studied variables as well as their interactions showed significant effects on the OLE loading. Higher temperatures favored the OLE loading while the pressure presented opposite effects at values higher than 250 bar. Thus, the highest OLE loadings were achieved at 250 bar and 55 °C for both polymers. However, TPU showed c.a. 4 times higher OLE loading and antioxidant activity in comparison with PLA at the optimal conditions. To the best of our knowledge, this is the first report using TPU for the supercritical impregnation of a natural extract with bioactivity.
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Modeling and Experiment for the Diffusion Coefficient of Subcritical Carbon Dioxide in Poly(methyl methacrylate) to Predict Gas Sorption and Desorption. Polymers (Basel) 2022; 14:polym14030596. [PMID: 35160585 PMCID: PMC8838939 DOI: 10.3390/polym14030596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/29/2022] [Accepted: 01/30/2022] [Indexed: 12/10/2022] Open
Abstract
Several researchers have investigated the phenomenon of polymer–gas mixtures, and a few have proposed diffusion coefficient values instead of a diffusion coefficient model. There is a paucity of studies focused on the continuous change in the diffusion coefficient corresponding to the overall pressure and temperature range of the mixture. In this study, the gas sorption and desorption experiments of poly(methyl methacrylate) (PMMA) were conducted via solid-state batch foaming, and the weight change was measured using the gravimetric method with a magnetic balance. The control parameters were temperature, which ranged from 290 to 370 K, and pressure, which ranged from 2 to 5 MPa in the subcritical regime. Based on the experimental data, the diffusion coefficient of the PMMA was calculated using Fick’s law. After calculating the diffusion coefficient in the range of the experiment, the diffusion coefficient model was employed using the least-squares method. Subsequently, the model was validated by comparing the obtained results with those in the literature, and the overall trend was found to be consistent. Therefore, it was confirmed that there were slight differences between the diffusion coefficient obtained using only Fick’s equation and the value using by a different method.
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