Bozhen Wu, Honghao Zhu, Yuhao Yang, Jiang Huang, Tong Liu, Tairong Kuang, Shaohua Jiang, A. Hejna, Kunming Liu
Abstract Due to the shortage of petroleum resources, poly(lactic acid) (PLA), a biodegradable polymer, has been widely considered as a replacement for traditional petroleum-based polymers. Therefore, multifunctional PLA composites have become increasingly popular. In this study, conductive carbon nanotubes (CNTs) and magnetic nano-Fe3O4 fillers were melt-blended with PLA. The impact of CNTs and nano-Fe3O4 composition on the electrical and electromagnetic interference (EMI) shielding properties of PLA nanocomposites was investigated in detail by adjusting the CNTs-to-nano-Fe3O4 ratio. When the hybrid filler content was fixed at 10 wt%, the electrical conductivity results indicated that the addition of single CNTs could effectively improve the conductivity of the nanocomposites, while nano-Fe3O4 contribution was hardly noted. A suitable ratio of electromagnetic hybrid fillers can yield excellent synergistic effects in EMI shielding properties. The nanocomposites containing CNTs and nano-Fe3O4 in a 50:50 ratio exhibited excellent electrical conductivity (90.6 S·m−1) and EMI shielding effectiveness (EMI SE ∼ 40.5 dB). This is primarily because CNTs provide good electrical conductivity, but the addition of magnetic nano-Fe3O4 provides additional interfacial polarization and eddy current losses caused by its dielectric and magnetic properties. These properties synergistically result in an impedance mismatch, dielectric loss, and polarization relaxation of the composite materials, improving the shielding properties against electromagnetic waves. Further, it was found that changing the ratio of electromagnetic hybrid fillers also affected electromagnetic wave absorption. When the ratio of CNT-to-nano-Fe3O4 was 25:75, the nanocomposites had an EMI SE of 24.6 dB, and the absorptivity could reach the maximum (40.3%). Thus, this study provides a valuable reference for preparing multifunctional polymer nanocomposites by constructing electromagnetic hybrid filler networks.
{"title":"Effect of different proportions of CNTs/Fe3O4 hybrid filler on the morphological, electrical and electromagnetic interference shielding properties of poly(lactic acid) nanocomposites","authors":"Bozhen Wu, Honghao Zhu, Yuhao Yang, Jiang Huang, Tong Liu, Tairong Kuang, Shaohua Jiang, A. Hejna, Kunming Liu","doi":"10.1515/epoly-2023-0006","DOIUrl":"https://doi.org/10.1515/epoly-2023-0006","url":null,"abstract":"Abstract Due to the shortage of petroleum resources, poly(lactic acid) (PLA), a biodegradable polymer, has been widely considered as a replacement for traditional petroleum-based polymers. Therefore, multifunctional PLA composites have become increasingly popular. In this study, conductive carbon nanotubes (CNTs) and magnetic nano-Fe3O4 fillers were melt-blended with PLA. The impact of CNTs and nano-Fe3O4 composition on the electrical and electromagnetic interference (EMI) shielding properties of PLA nanocomposites was investigated in detail by adjusting the CNTs-to-nano-Fe3O4 ratio. When the hybrid filler content was fixed at 10 wt%, the electrical conductivity results indicated that the addition of single CNTs could effectively improve the conductivity of the nanocomposites, while nano-Fe3O4 contribution was hardly noted. A suitable ratio of electromagnetic hybrid fillers can yield excellent synergistic effects in EMI shielding properties. The nanocomposites containing CNTs and nano-Fe3O4 in a 50:50 ratio exhibited excellent electrical conductivity (90.6 S·m−1) and EMI shielding effectiveness (EMI SE ∼ 40.5 dB). This is primarily because CNTs provide good electrical conductivity, but the addition of magnetic nano-Fe3O4 provides additional interfacial polarization and eddy current losses caused by its dielectric and magnetic properties. These properties synergistically result in an impedance mismatch, dielectric loss, and polarization relaxation of the composite materials, improving the shielding properties against electromagnetic waves. Further, it was found that changing the ratio of electromagnetic hybrid fillers also affected electromagnetic wave absorption. When the ratio of CNT-to-nano-Fe3O4 was 25:75, the nanocomposites had an EMI SE of 24.6 dB, and the absorptivity could reach the maximum (40.3%). Thus, this study provides a valuable reference for preparing multifunctional polymer nanocomposites by constructing electromagnetic hybrid filler networks.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42880224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peng Chen, Qihong Zhou, Ge Chen, Yuntao Wang, Jing Lv
Abstract In the electrospinning process, the Taylor cone, as the jet source, directly affects the jet movement and the quality of the fiber membrane. Therefore, to understand the formation mechanism of the Taylor cone intuitively, a multiphysics coupling model that comprehensively considers the gravitational field, electrostatic field, and fluid field is established, and numerical simulations are conducted in this study. First, we construct a level-set function and analyze the force of the droplet. The gravity, surface tension, and electric field force are coupled to the incompressible Navier–Stokes equation as volume forces, and the nonconservation of the droplet area is solved by approximating the Dirac function with a smooth function. Subsequently, the deformation of the electrospun polyacrylonitrile (PAN) Taylor cone under different process parameters is simulated. Finally, data obtained from the numerical simulation and the average diameter of the electrospun PAN fiber membrane are analyzed via gray relational analysis. The results show that the volume force is the key factor affecting the average diameter of the fiber membrane (the correlation is 0.934). This article provides an effective reference and basis for the analysis and control of the electrospinning process.
{"title":"Numerical simulation and experimental research of electrospun polyacrylonitrile Taylor cone based on multiphysics coupling","authors":"Peng Chen, Qihong Zhou, Ge Chen, Yuntao Wang, Jing Lv","doi":"10.1515/epoly-2022-8106","DOIUrl":"https://doi.org/10.1515/epoly-2022-8106","url":null,"abstract":"Abstract In the electrospinning process, the Taylor cone, as the jet source, directly affects the jet movement and the quality of the fiber membrane. Therefore, to understand the formation mechanism of the Taylor cone intuitively, a multiphysics coupling model that comprehensively considers the gravitational field, electrostatic field, and fluid field is established, and numerical simulations are conducted in this study. First, we construct a level-set function and analyze the force of the droplet. The gravity, surface tension, and electric field force are coupled to the incompressible Navier–Stokes equation as volume forces, and the nonconservation of the droplet area is solved by approximating the Dirac function with a smooth function. Subsequently, the deformation of the electrospun polyacrylonitrile (PAN) Taylor cone under different process parameters is simulated. Finally, data obtained from the numerical simulation and the average diameter of the electrospun PAN fiber membrane are analyzed via gray relational analysis. The results show that the volume force is the key factor affecting the average diameter of the fiber membrane (the correlation is 0.934). This article provides an effective reference and basis for the analysis and control of the electrospinning process.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45836709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A series of aliphatic amine-functionalized multiwalled carbon nanotubes (MWCNTs) wherein varied secondary amine numbers were grafted on the MWCNTs’ surface were synthesized and further dispersed onto the glass fibers for reinforcing epoxy-based composites. By tuning secondary amine numbers of aliphatic amines, the dispersion of MWCNTs and ultimately mechanical, thermal, and conductive properties of epoxy-based composites could be adjusted. Using an optimal secondary amine number of aliphatic amine (triethylenetetramine), the interlaminar shear strength, tensile strength, and flexural strength of epoxy-based composite increased by 43.9%, 34.8%, and 35.0%, respectively; the work of fracture after interlaminar shear tests increased by 233.9%, suggesting strengthening/toughening effects of functionalized MWCNTs; significant reduction in surface resistance and increased thermal conductivity were also obtained, implying the superior conductive properties for composites. This work offers a new strategy for designing fiber-reinforced composites with high strength, excellent antistatic properties, and good thermal conductivity for medical device applications.
{"title":"High strength, anti-static, thermal conductive glass fiber/epoxy composites for medical devices: A strategy of modifying fibers with functionalized carbon nanotubes","authors":"Yue Li, Shaohua Zeng","doi":"10.1515/epoly-2023-0123","DOIUrl":"https://doi.org/10.1515/epoly-2023-0123","url":null,"abstract":"Abstract A series of aliphatic amine-functionalized multiwalled carbon nanotubes (MWCNTs) wherein varied secondary amine numbers were grafted on the MWCNTs’ surface were synthesized and further dispersed onto the glass fibers for reinforcing epoxy-based composites. By tuning secondary amine numbers of aliphatic amines, the dispersion of MWCNTs and ultimately mechanical, thermal, and conductive properties of epoxy-based composites could be adjusted. Using an optimal secondary amine number of aliphatic amine (triethylenetetramine), the interlaminar shear strength, tensile strength, and flexural strength of epoxy-based composite increased by 43.9%, 34.8%, and 35.0%, respectively; the work of fracture after interlaminar shear tests increased by 233.9%, suggesting strengthening/toughening effects of functionalized MWCNTs; significant reduction in surface resistance and increased thermal conductivity were also obtained, implying the superior conductive properties for composites. This work offers a new strategy for designing fiber-reinforced composites with high strength, excellent antistatic properties, and good thermal conductivity for medical device applications.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135057735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The use of natural polysaccharides in stretchable hydrogels has attracted more and more attention. However, pure polyvinyl alcohol (PVA) hydrogel has poor mechanical properties and low sensitivity in strain sensors. Composite hydrogels with high tensile properties (the storage modulus of 6,397.8 Pa and the loss modulus of 3,283.9 Pa) and high electrical conductivity (1.57 S·m−1) were prepared using a simple method. The Fe-vermiculite and lignocellulosic nanofibril-based hydrogels were applied as reliable and stable strain sensors that are responsive to environmental stimuli. The prepared hydrogels exhibited excellent ionic conductivity, which satisfied the needs of wrist flexion activity monitoring. The results showed that the PVA/LF0.4 hydrogel has a natural formulation, high mechanical strength, and electrical conductivity, which has great potential for application in artificial electronics. Graphical abstract Schematic illustration of the fabrication of the PVA/LF0.4 hydrogel, which is then used as conductive hydrogel in electron skin sensors due to excellently tensile (596.7%) and highly conductive (1.57 S‧m−1) properties.
{"title":"High-strength polyvinyl alcohol-based hydrogel by vermiculite and lignocellulosic nanofibrils for electronic sensing","authors":"Yaxin Hu, Jing Luo, Shipeng Luo, Tong Fei, Mingyao Song, Hengfei Qin","doi":"10.1515/epoly-2023-0081","DOIUrl":"https://doi.org/10.1515/epoly-2023-0081","url":null,"abstract":"Abstract The use of natural polysaccharides in stretchable hydrogels has attracted more and more attention. However, pure polyvinyl alcohol (PVA) hydrogel has poor mechanical properties and low sensitivity in strain sensors. Composite hydrogels with high tensile properties (the storage modulus of 6,397.8 Pa and the loss modulus of 3,283.9 Pa) and high electrical conductivity (1.57 S·m−1) were prepared using a simple method. The Fe-vermiculite and lignocellulosic nanofibril-based hydrogels were applied as reliable and stable strain sensors that are responsive to environmental stimuli. The prepared hydrogels exhibited excellent ionic conductivity, which satisfied the needs of wrist flexion activity monitoring. The results showed that the PVA/LF0.4 hydrogel has a natural formulation, high mechanical strength, and electrical conductivity, which has great potential for application in artificial electronics. Graphical abstract Schematic illustration of the fabrication of the PVA/LF0.4 hydrogel, which is then used as conductive hydrogel in electron skin sensors due to excellently tensile (596.7%) and highly conductive (1.57 S‧m−1) properties.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43960971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. A. Alorain, M. I. Sayyed, A. Almuqrin, K. Mahmoud
Abstract A series of polyepoxide resins doped by lead oxide with low concentrations were fabricated in order to study the impacts of low PbO concentrations on the fabricated composites’ physical- and radiation-shielding properties. The epoxide resin was reinforced with the PbO compound with concentrations 0, 5, and 10 wt%. The density measurements affirmed that by elevating the PbO concentration between 0 and 10 wt%, the composites’ density increased from 1.103 to 1.185 g·cm−3. This low-density increase was echoed in the fabricated composites’ radiation-shielding properties, where the Monte Carlo simulation code affirmed a linear attenuation coefficient increase by factors of 230%, 218%, 24%, and 10%, respectively, at 59, 121, 356, and 662 keV. The half-value layer, mean free path, and transmission factor indicated a linear attenuation coefficient enhancement.
{"title":"Impacts of micro-size PbO on the gamma-ray shielding performance of polyepoxide resin","authors":"D. A. Alorain, M. I. Sayyed, A. Almuqrin, K. Mahmoud","doi":"10.1515/epoly-2023-0032","DOIUrl":"https://doi.org/10.1515/epoly-2023-0032","url":null,"abstract":"Abstract A series of polyepoxide resins doped by lead oxide with low concentrations were fabricated in order to study the impacts of low PbO concentrations on the fabricated composites’ physical- and radiation-shielding properties. The epoxide resin was reinforced with the PbO compound with concentrations 0, 5, and 10 wt%. The density measurements affirmed that by elevating the PbO concentration between 0 and 10 wt%, the composites’ density increased from 1.103 to 1.185 g·cm−3. This low-density increase was echoed in the fabricated composites’ radiation-shielding properties, where the Monte Carlo simulation code affirmed a linear attenuation coefficient increase by factors of 230%, 218%, 24%, and 10%, respectively, at 59, 121, 356, and 662 keV. The half-value layer, mean free path, and transmission factor indicated a linear attenuation coefficient enhancement.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43794931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In the production of powder-coating polyester, a strong odor emanates from the water, prompting us to investigate its composition and origin. We studied the process of powder coating epoxy/polyester 50/50, which employs butyl tin tris (2-ethyl hexanoate) as a catalyst. The esterified water was extracted using ethyl acetate. It was analyzed via GC–MS to identify the side reactions and by-products that arise during the tin-catalyzed esterification process. Then we discussed their formation mechanism. Our results indicate that butyl tin tris (2-ethyl hexanoate) triggers side reactions such as cyclization and transesterification, leading to the production of by-products such as heterocyclic compounds (1,4-dioxane), anhydride compounds (propionic anhydride), and others. Notably, the unpleasant odor was found to be derived from propionic anhydride. These findings provide insights into the chemistry of tin-catalyzed esterification and highlight the importance of addressing the formation of unwanted by-products in the production of powder-coating polyester.
{"title":"Study on by-products synthesis of powder coating polyester resin catalyzed by organotin","authors":"Yucheng Yang, Chao Di, Tingwei Wang","doi":"10.1515/epoly-2023-0018","DOIUrl":"https://doi.org/10.1515/epoly-2023-0018","url":null,"abstract":"Abstract In the production of powder-coating polyester, a strong odor emanates from the water, prompting us to investigate its composition and origin. We studied the process of powder coating epoxy/polyester 50/50, which employs butyl tin tris (2-ethyl hexanoate) as a catalyst. The esterified water was extracted using ethyl acetate. It was analyzed via GC–MS to identify the side reactions and by-products that arise during the tin-catalyzed esterification process. Then we discussed their formation mechanism. Our results indicate that butyl tin tris (2-ethyl hexanoate) triggers side reactions such as cyclization and transesterification, leading to the production of by-products such as heterocyclic compounds (1,4-dioxane), anhydride compounds (propionic anhydride), and others. Notably, the unpleasant odor was found to be derived from propionic anhydride. These findings provide insights into the chemistry of tin-catalyzed esterification and highlight the importance of addressing the formation of unwanted by-products in the production of powder-coating polyester.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46292660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A thorough comparative analysis was conducted between pure epoxy and a novel epoxy composite that included bentonite and WO3 nanoparticles in varying ratios. This study examined five distinct novel epoxy samples (E00, EB0, EBW1, EBW2, and EBW3) to assess their radiation shielding efficiency (RSE), taking into account the addition of bentonite and WO3 nanoparticles. Furthermore, the study compared the RSE of pure epoxy with that of the novel epoxy composite. To evaluate the radiation shielding ability of the studied epoxy samples, a few radiation shielding parameters such as linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), mean free path (MFP), RSE, and transition factor (I/I 0) were calculated. The RSE values of the epoxy samples were E00 (63.41%), EB0 (87.17%), EBW1 (98.26%), EBW2 (99.82%), and EBW3 (99.99%) at an energy of 0.06 MeV with 4 cm thickness. With the increase in the incident energy, the half-value layer and MFP values were increased, whereas the LAC and MAC values decreased. In conclusion, it can be stated that the sample EBW3 is more suitable among the five epoxy samples studied for attenuating the incident photon energy from 0.06 to 1.33 MeV. Noteworthily, the obtained results demonstrate that the addition of WO3 nanoparticles enhances the shielding ability of epoxy when compared to the addition of the same amount of bentonite.
{"title":"The affinity of bentonite and WO3 nanoparticles toward epoxy resin polymer for radiation shielding","authors":"M. Elsafi, A. Almuqrin, S. Yasmin, M. I. Sayyed","doi":"10.1515/epoly-2023-0011","DOIUrl":"https://doi.org/10.1515/epoly-2023-0011","url":null,"abstract":"Abstract A thorough comparative analysis was conducted between pure epoxy and a novel epoxy composite that included bentonite and WO3 nanoparticles in varying ratios. This study examined five distinct novel epoxy samples (E00, EB0, EBW1, EBW2, and EBW3) to assess their radiation shielding efficiency (RSE), taking into account the addition of bentonite and WO3 nanoparticles. Furthermore, the study compared the RSE of pure epoxy with that of the novel epoxy composite. To evaluate the radiation shielding ability of the studied epoxy samples, a few radiation shielding parameters such as linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), mean free path (MFP), RSE, and transition factor (I/I 0) were calculated. The RSE values of the epoxy samples were E00 (63.41%), EB0 (87.17%), EBW1 (98.26%), EBW2 (99.82%), and EBW3 (99.99%) at an energy of 0.06 MeV with 4 cm thickness. With the increase in the incident energy, the half-value layer and MFP values were increased, whereas the LAC and MAC values decreased. In conclusion, it can be stated that the sample EBW3 is more suitable among the five epoxy samples studied for attenuating the incident photon energy from 0.06 to 1.33 MeV. Noteworthily, the obtained results demonstrate that the addition of WO3 nanoparticles enhances the shielding ability of epoxy when compared to the addition of the same amount of bentonite.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47643921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mengtong Zhou, Hao-Ran Wang, Xing Guo, Yanchan Wei, S. Liao
Abstract The oxidation of natural rubber (NR) leads to a decrease in mechanical properties, even resulting in failure of NR products. Many studies focusing on this single factor have failed to fully elucidate the impact of tropical island environment on NR properties. Based on this concern, the synergistic effect of thermal oxygen and ultraviolet (UV) aging on NR was systematically studied. The results revealed that thermal oxygenation can promote UV aging, which leads to the appearance of surface cracks and deepening of color. With the extension of aging time, the mechanical properties of NR correspondingly decreased. Besides, to deeply understand the mechanism of the synergistic effect of thermal oxygen and UV aging on NR, we selected squalene to simulate and analyze the molecular structure changes in NR. Based on these results, a possible synergistic effect of thermal oxygen and UV aging mechanisms on NR could be proposed.
{"title":"Synergistic effect of thermal oxygen and UV aging on natural rubber","authors":"Mengtong Zhou, Hao-Ran Wang, Xing Guo, Yanchan Wei, S. Liao","doi":"10.1515/epoly-2023-0016","DOIUrl":"https://doi.org/10.1515/epoly-2023-0016","url":null,"abstract":"Abstract The oxidation of natural rubber (NR) leads to a decrease in mechanical properties, even resulting in failure of NR products. Many studies focusing on this single factor have failed to fully elucidate the impact of tropical island environment on NR properties. Based on this concern, the synergistic effect of thermal oxygen and ultraviolet (UV) aging on NR was systematically studied. The results revealed that thermal oxygenation can promote UV aging, which leads to the appearance of surface cracks and deepening of color. With the extension of aging time, the mechanical properties of NR correspondingly decreased. Besides, to deeply understand the mechanism of the synergistic effect of thermal oxygen and UV aging on NR, we selected squalene to simulate and analyze the molecular structure changes in NR. Based on these results, a possible synergistic effect of thermal oxygen and UV aging mechanisms on NR could be proposed.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49477568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
YaoWen Yin, M. Jiao, AnFei Liu, Hao Wang, Yang Liu, Y. Liu, Kaifeng Yang, Genxing Zhu
Abstract This article proposes the preparation and microwave thermal cured (MTC) epoxy-modified phenolic fibers for the first time. Epoxy-modified thermoplastic phenolic resin was first prepared in acidic condition using phenol, formaldehyde, and epichlorohydrin as the reactants, and then underwent additive reaction with formaldehyde to obtain epoxy-modified thermosetting phenolic resin, which was converted into nascent fibers through wet spinning. Finally, epoxy-modified phenolic fibers were obtained through different curing methods including solution cured, solution thermal cured, microwave cured, MTC, and was characterized by infrared spectroscopy, microscopic infrared imaging, nuclear magnetic resonance, thermogravimetric analysis, and scanning electron microscopy. The experiment results show that MTC epoxy-modified phenolic fibers have optimal mechanical property with ultimate elongation of 4% and breaking strength of 133 MPa. Graphical abstract
{"title":"Preparation and properties of epoxy-modified thermosetting phenolic fiber","authors":"YaoWen Yin, M. Jiao, AnFei Liu, Hao Wang, Yang Liu, Y. Liu, Kaifeng Yang, Genxing Zhu","doi":"10.1515/epoly-2022-8085","DOIUrl":"https://doi.org/10.1515/epoly-2022-8085","url":null,"abstract":"Abstract This article proposes the preparation and microwave thermal cured (MTC) epoxy-modified phenolic fibers for the first time. Epoxy-modified thermoplastic phenolic resin was first prepared in acidic condition using phenol, formaldehyde, and epichlorohydrin as the reactants, and then underwent additive reaction with formaldehyde to obtain epoxy-modified thermosetting phenolic resin, which was converted into nascent fibers through wet spinning. Finally, epoxy-modified phenolic fibers were obtained through different curing methods including solution cured, solution thermal cured, microwave cured, MTC, and was characterized by infrared spectroscopy, microscopic infrared imaging, nuclear magnetic resonance, thermogravimetric analysis, and scanning electron microscopy. The experiment results show that MTC epoxy-modified phenolic fibers have optimal mechanical property with ultimate elongation of 4% and breaking strength of 133 MPa. Graphical abstract","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48759904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alka Singh, Nakshatra Bahadur Singh, Kanu Priya, Richa Tomar, Mohammed Saeed Al-Qahtani, Mohammad Tarique Imam, Ziyad Saeed Almalki, Waleed Al Abdulmonem, Krishna Kumar Yadav, Hyun-Kyung Park
Abstract Cancers are complicated sicknesses that happen because of many different things going wrong in cells, and as they get worse, the cells undergo many changes one after another. Nanomedicine is a new way to treat diseases like cancer. Tiny particles called nanoparticles have special properties that can help to treat diseases better than regular treatments. These particles are very small but have a lot of surface area, can carry different drugs, and can be designed to target specific areas. They can move around the body, go into cells, and release drugs slowly. Because of these benefits, nanoparticles could be better for cancer treatment. In this continuous research, we present a simple technique for the quick and single-step synthesis of ZnFe 2 O 4 /cellulose nanocomposites, employing the polymer cellulose. This method is not only cost-effective but also environment friendly. Scanning electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, and the ultraviolet-visible (UV) spectrum were all used to examine the morphological, structural, and electrical properties of ZnFe 2 O 4 /cellulose nanocomposites. The nanocomposite derived from UV-DRS exhibits an optical energy bandgap of 1.8 eV. The mechanical strength of the composites gradually increases as ZnFe 2 O 4 is added to the cellulose polymer matrix. These findings propose a straightforward and innovative approach to produce ZnFe 2 O 4 /cellulose nanocomposites that can serve as functional biomaterials. In addition, the ZnFe 2 O 4 /cellulose nanocomposite exhibits decreased antioxidant activity compared to ascorbic acid. ZnFe 2 O 4 /cellulose nanocomposite was found to have an IC 50 of 49.64 g·mL −1 . With an IC 50 value of 55.91 g·mL −1 , the synthesized ZnFe 2 O 4 /cellulose nanocomposites demonstrate significant cytotoxicity in a dose-dependent manner against the lung cancer cell lines A549. In conclusion, nanocomposites are potential materials for usage in biomedical applications due to their affordable production and mild magnetic sensitivity.
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