Pub Date : 2024-11-21DOI: 10.1016/j.polymer.2024.127867
Athmen Zenati, Kisan Koirala
Novel silicon-based liquid crystalline (LC) monomer (CASPA) and corresponding Poly(MMA)-b-Poly(CASPA) diblock copolymers (DBCs) containing symmetric azobenzene mesogens in the side chain were successfully synthesized by coupling reaction and reversible addition-fragmentation chain transfer (RAFT) polymerization, respectively. Block copolymerization by RAFT proceeded with well-controlled manner in anisole solution involving new CASPA monomer, Poly(MMA)-RAFT macroinitiator and AIBN initiator, yielding Poly(MMA)-b-Poly(CASPA) DBCs with excellent control over molecular weights (Mw/Mn ≤ 1.39) and compositions. Chemical structures and properties of CASPA and Poly(MMA)-b-Poly(CASPA) were extensively studied using 1H NMR, FTIR, GPC, DSC, POM, AFM and GISAXS. The CASPA exhibited enantiotropic liquid crystallinity with nematic four-brush schlieren texture, while DBCs showed monotropic liquid crystallinity with batonnet textures of smectic A phase. All DBC films exhibited photochemical trans-cis isomerization and photoinduced phase transition from mesophase to isotropic phase under UV irradiation. Morphologies of DBC thin films under thermal annealing depended on volume ratio of building LC block relative to Poly(MMA) segment, DBC-2 containing approximately equal block volume fractions self-assembled into lamellar nanostructure with domain-spacing of 34 nm, whereas DBC-3 and DBC-4 possessing higher LC contents (65 wt% and 72 wt%) formed highly ordered hexagonal cylindrical nanostructures with domain-spacing ranging from 37 to 39 nm as evidence by AFM and GI-SAXS, conforming with the self-consistent field theory.
{"title":"Synthesis, Characteristics and Thermally Induced Self-Assembly of Silicon-Based Thermo/Photo-Responsive Block Copolymers Prepared from Monomer Bearing Paired Side-Chain Azo Mesogens Using RAFT Process","authors":"Athmen Zenati, Kisan Koirala","doi":"10.1016/j.polymer.2024.127867","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127867","url":null,"abstract":"Novel silicon-based liquid crystalline (LC) monomer (CASPA) and corresponding Poly(MMA)-b-Poly(CASPA) diblock copolymers (DBCs) containing symmetric azobenzene mesogens in the side chain were successfully synthesized by coupling reaction and reversible addition-fragmentation chain transfer (RAFT) polymerization, respectively. Block copolymerization by RAFT proceeded with well-controlled manner in anisole solution involving new CASPA monomer, Poly(MMA)-RAFT macroinitiator and AIBN initiator, yielding Poly(MMA)-b-Poly(CASPA) DBCs with excellent control over molecular weights (Mw/Mn ≤ 1.39) and compositions. Chemical structures and properties of CASPA and Poly(MMA)-b-Poly(CASPA) were extensively studied using <sup>1</sup>H NMR, FTIR, GPC, DSC, POM, AFM and GISAXS. The CASPA exhibited enantiotropic liquid crystallinity with nematic four-brush schlieren texture, while DBCs showed monotropic liquid crystallinity with batonnet textures of smectic A phase. All DBC films exhibited photochemical trans-cis isomerization and photoinduced phase transition from mesophase to isotropic phase under UV irradiation. Morphologies of DBC thin films under thermal annealing depended on volume ratio of building LC block relative to Poly(MMA) segment, DBC-2 containing approximately equal block volume fractions self-assembled into lamellar nanostructure with domain-spacing of 34 nm, whereas DBC-3 and DBC-4 possessing higher LC contents (65 wt% and 72 wt%) formed highly ordered hexagonal cylindrical nanostructures with domain-spacing ranging from 37 to 39 nm as evidence by AFM and GI-SAXS, conforming with the self-consistent field theory.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"38 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.polymer.2024.127861
Laura Abad Galán, Paula Cruz, Estefanía Fernández-Bartolomé, Miguel Cortijo, Patricia Delgado-Martínez, Rodrigo González-Prieto, Reyes Jiménez-Aparicio, José L. Priego
The synthesis, characterization and structural determination of four complexes with formula (PPh4)n{[Rh2(μ-O2CPh)4][Au(CN)2]}n (1) and Kn{[Rh2(μ-O2CR)4][M(CN)2]}n (M = Au, R = CH2OEt (2), CH2OMe (3); M = Ag, R = CH2OMe (4)) are described. In all cases, the [CN-M-CN]– (M = Au, Ag) group is bridging the axial positions of the dirhodium units giving one-dimensional chains. The packing of the chains in the solid state depends on the nature of the carboxylate group of the dimetallic unit, the counterion present in the complex and the metal itself. The most striking change is observed in the Kn{[Rh2(μ-O2CCH2OMe)4][Au(CN)2]}n complex (3), where the chains are positioned perpendicular to each other with an Au···Au interchain distance of 2.963 Å. The emission studies of this complex upon excitation at 350 nm show a clear broad emission band centered at 430 nm, while no luminescence is observed for the other compounds. The appearance of emission properties only in the case of complex 3 can be explained by its short aurophilic interactions.
本文介绍了四种络合物的合成、表征和结构测定，它们的化学式分别为 (PPh4)n{[Rh2(μ-O2CPh)4][Au(CN)2]}n (1) 和 Kn{[Rh2(μ-O2CR)4][M(CN)2]}n (M = Au, R = CH2OEt (2), CH2OMe (3); M = Ag, R = CH2OMe (4))。在所有情况下，[CN-M-CN]-（M = Au、Ag）基团都桥接在二铑单元的轴向位置，形成一维链。固态链的堆积取决于二金属单元的羧酸基团、配合物中的反离子和金属本身的性质。在 Kn{[Rh2(μ-O2CCH2OMe)4][Au(CN)2]}n（3）复合物中观察到了最显著的变化，其中链的位置相互垂直，Au--Au 链间距离为 2.963 Å。只有复合物 3 具有发射特性，这可以用它的短亲欧相互作用来解释。
{"title":"Anionic Polymers Formed by Dinuclear Rhodium Units and Dicyanide Silver/Gold Moieties","authors":"Laura Abad Galán, Paula Cruz, Estefanía Fernández-Bartolomé, Miguel Cortijo, Patricia Delgado-Martínez, Rodrigo González-Prieto, Reyes Jiménez-Aparicio, José L. Priego","doi":"10.1016/j.polymer.2024.127861","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127861","url":null,"abstract":"The synthesis, characterization and structural determination of four complexes with formula (PPh<sub>4</sub>)<sub>n</sub>{[Rh<sub>2</sub>(μ-O<sub>2</sub>CPh)<sub>4</sub>][Au(CN)<sub>2</sub>]}<sub>n</sub> (<strong>1</strong>) and K<sub>n</sub>{[Rh<sub>2</sub>(μ-O<sub>2</sub>CR)<sub>4</sub>][M(CN)<sub>2</sub>]}<sub>n</sub> (M = Au, R = CH<sub>2</sub>OEt (<strong>2</strong>), CH<sub>2</sub>OMe (<strong>3</strong>); M = Ag, R = CH<sub>2</sub>OMe <strong>(4</strong>)) are described. In all cases, the [CN-M-CN]<sup>–</sup> (M = Au, Ag) group is bridging the axial positions of the dirhodium units giving one-dimensional chains. The packing of the chains in the solid state depends on the nature of the carboxylate group of the dimetallic unit, the counterion present in the complex and the metal itself. The most striking change is observed in the K<sub>n</sub>{[Rh<sub>2</sub>(μ-O<sub>2</sub>CCH<sub>2</sub>OMe)<sub>4</sub>][Au(CN)<sub>2</sub>]}<sub>n</sub> complex (<strong>3</strong>), where the chains are positioned perpendicular to each other with an Au···Au interchain distance of 2.963 Å. The emission studies of this complex upon excitation at 350 nm show a clear broad emission band centered at 430 nm, while no luminescence is observed for the other compounds. The appearance of emission properties only in the case of complex <strong>3</strong> can be explained by its short aurophilic interactions.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"18 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.polymer.2024.127858
Fatemeh Gandomkar, Mostafa Khajeh, Ali Reza Oveisi, Pouya Karimi, Hermenegildo García
In this research, a new porphyrin-based porous organic polymer (POP), named here PPOP-UOZ-1 (UOZ stands for the University of Zabol), was synthesized through a solvothermal condensation reaction between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP, Porph-NH2) and 2,2'-[ethane-1,2-diylbis(oxy)]dibenzaldehyde (Dialdehyde, DA). The chemical structure, morphology, and surface properties of the PPOP-UOZ-1 were assessed using numerous techniques, including TGA, BET, FT- IR, PXRD, and SEM/EDX. The nominal PPOP-UOZ-1 was then used as an adsorbent for selective (better than 92%) extraction of Pd(II) from aqueous solutions. The adsorption process was optimized by studying the effect of various factors such as pH, the type and volume of eluent, adsorption and desorption time, and the amount of adsorbent. The results exhibited that the maximum adsorption capacity of PPOP-UOZ-1 for Pd(II) was 208.3 mg/g at a pH of 3.0, based on the Langmuir isotherm model (a determination coefficient of 0.9887). The adsorbent showed excellent selectivity for Pd(II) over other coexisting metal ions, with a recovery rate higher than 92%. Furthermore, the PPOP-UOZ-1 could be reused for at least six adsorption-desorption cycles without substantial loss of efficiency. This proposed adsorbent and approach was further applicable for the efficient extraction of Pd(II) from environmental water samples.
{"title":"Preparation of a novel porous organic polymer for selective extraction/determination of palladium ions from water samples","authors":"Fatemeh Gandomkar, Mostafa Khajeh, Ali Reza Oveisi, Pouya Karimi, Hermenegildo García","doi":"10.1016/j.polymer.2024.127858","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127858","url":null,"abstract":"In this research, a new porphyrin-based porous organic polymer (POP), named here PPOP-UOZ-1 (UOZ stands for the University of Zabol), was synthesized through a solvothermal condensation reaction between 5,10,15,20-<strong>t</strong>etrakis(4-<strong>a</strong>mino<strong>p</strong>henyl)<strong>p</strong>orphyrin (TAPP, Porph-NH<sub>2</sub>) and 2,2'-[ethane-1,2-diylbis(oxy)]<strong>d</strong>ibenz<strong>a</strong>ldehyde (Dialdehyde, DA). The chemical structure, morphology, and surface properties of the PPOP-UOZ-1 were assessed using numerous techniques, including TGA, BET, FT- IR, PXRD, and SEM/EDX. The nominal PPOP-UOZ-1 was then used as an adsorbent for selective (better than 92%) extraction of Pd(II) from aqueous solutions. The adsorption process was optimized by studying the effect of various factors such as pH, the type and volume of eluent, adsorption and desorption time, and the amount of adsorbent. The results exhibited that the maximum adsorption capacity of PPOP-UOZ-1 for Pd(II) was 208.3 mg/g at a pH of 3.0, based on the Langmuir isotherm model (a determination coefficient of 0.9887). The adsorbent showed excellent selectivity for Pd(II) over other coexisting metal ions, with a recovery rate higher than 92%. Furthermore, the PPOP-UOZ-1 could be reused for at least six adsorption-desorption cycles without substantial loss of efficiency. This proposed adsorbent and approach was further applicable for the efficient extraction of Pd(II) from environmental water samples.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"15 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.polymer.2024.127868
Songhao Mo, Hong Ruan, Yuqi Li
Triboelectric nanogenerators (TENGs) are eco-friendly energy harvesters. Polyimide (PI) has been widely used as a triboelectric layer in TENGs, but the relationship between its structure and performance is not fully understood. Herein, PI films with varying molecular structures were prepared to investigate the effects of -O- and -CF3 groups on their physical properties and triboelectric performance. The results showed that PI films with -O- exhibited better thermal stability, while both -O- and -CF3 groups effectively modulated optical transparency and dielectric properties. At 450 nm, M6-PI and O6-PI exhibited the highest transmittance at 63.14% and 55.06%, respectively, with dielectric loss performance below 0.5% at 105 Hz. PI films incorporating -O- and -CF3 demonstrated significant improvements in triboelectric performance. Theoretical calculations clarified these groups influence optical transparency, dielectric properties, and electrical output performance. Ultimately, the fabricated 6PI-TENG achieved the desired triboelectric performance with enhanced electrical output. The Voc and Qsc of 6PI reached approximately 80 V and 25 nC, respectively. This study offers essential theoretical insights for designing and advancing of TENGs, contributing to sustainable energy development.
三电纳米发电机（TENGs）是一种生态友好型能量收集器。聚酰亚胺（PI）已被广泛用作 TENG 的三电层，但其结构与性能之间的关系尚未完全明了。本文制备了不同分子结构的聚酰亚胺薄膜，研究了-O-和-CF3基团对其物理性质和三电性能的影响。结果表明，带有 -O- 的 PI 薄膜具有更好的热稳定性，而 -O- 和 -CF3 基团则能有效调节光学透明度和介电性能。在 450 纳米波长下，M6-PI 和 O6-PI 的透光率最高，分别为 63.14% 和 55.06%，在 105 Hz 频率下的介电损耗性能低于 0.5%。含有 -O- 和 -CF3 的 PI 薄膜在三电性能方面有显著改善。理论计算阐明了这些基团对光学透明度、介电性能和电输出性能的影响。最终，制造出的 6PI-TENG 实现了理想的三电性能，并增强了电输出。6PI 的 Voc 和 Qsc 分别达到了约 80 V 和 25 nC。这项研究为设计和推进 TENG 提供了重要的理论启示，有助于可持续能源发展。
{"title":"Relationship between the molecular structure of polyimide and its dielectric properties: Optimizing performance for triboelectric nanogenerators","authors":"Songhao Mo, Hong Ruan, Yuqi Li","doi":"10.1016/j.polymer.2024.127868","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127868","url":null,"abstract":"Triboelectric nanogenerators (TENGs) are eco-friendly energy harvesters. Polyimide (PI) has been widely used as a triboelectric layer in TENGs, but the relationship between its structure and performance is not fully understood. Herein, PI films with varying molecular structures were prepared to investigate the effects of -O- and -CF<sub>3</sub> groups on their physical properties and triboelectric performance. The results showed that PI films with -O- exhibited better thermal stability, while both -O- and -CF<sub>3</sub> groups effectively modulated optical transparency and dielectric properties. At 450 nm, M6-PI and O6-PI exhibited the highest transmittance at 63.14% and 55.06%, respectively, with dielectric loss performance below 0.5% at 10<sup>5</sup> Hz. PI films incorporating -O- and -CF<sub>3</sub> demonstrated significant improvements in triboelectric performance. Theoretical calculations clarified these groups influence optical transparency, dielectric properties, and electrical output performance. Ultimately, the fabricated 6PI-TENG achieved the desired triboelectric performance with enhanced electrical output. The V<sub>oc</sub> and Q<sub>sc</sub> of 6PI reached approximately 80 V and 25 nC, respectively. This study offers essential theoretical insights for designing and advancing of TENGs, contributing to sustainable energy development.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"4 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.polymer.2024.127869
Yasser Zare, Muhammad Tajammal Munir, Kyong Yop Rhee, Soo-Jin Park
Current modeling approaches for the conductivity of polymer composites containing carbon nanofiber (CNF) called as PCNFs exhibit limitations. Herein, we introduce an enhanced Ouali model to accurately forecast the PCNF conductivity by incorporating the operative CNF amount and the conductivity contributions of CNFs, interphase region, and tunneling zones. The effective CNF volume fraction is derived from the dimensions of both CNFs and interphase, while the overall conductivity calculation integrates the resistances of interphase region and tunnels. The model's accuracy is validated through empirical conductivity measurements of various PCNF samples and extensive parametric analyses. An interphase depth (t) of less than 8 nm renders the composite insulative, whereas peak conductivity of 0.04 S/m is achieved at an interphase depth of 40 nm and interphase conductivity of 400 S/m. These results underscore the significant influence of interphase depth and conductivity on the overall electrical performance of the composites. Furthermore, a CNF length (l) below 13 μm or a contact diameter (d) under 10 nm also results in an insulative composite. Conversely, maximum values of CNF length (80 μm) and contact diameter (40 nm) enhance the composite's conductivity to 0.1 S/m. These findings illustrate the advantageous impact of longer nanofibers and wider tunnels on the electrical conductivity of PCNFs.
{"title":"A New Method for Conductivity Prediction in Polymer Carbon Nanofiber System by the Interphase Size and Total Conductivity of Constituents","authors":"Yasser Zare, Muhammad Tajammal Munir, Kyong Yop Rhee, Soo-Jin Park","doi":"10.1016/j.polymer.2024.127869","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127869","url":null,"abstract":"Current modeling approaches for the conductivity of polymer composites containing carbon nanofiber (CNF) called as PCNFs exhibit limitations. Herein, we introduce an enhanced Ouali model to accurately forecast the PCNF conductivity by incorporating the operative CNF amount and the conductivity contributions of CNFs, interphase region, and tunneling zones. The effective CNF volume fraction is derived from the dimensions of both CNFs and interphase, while the overall conductivity calculation integrates the resistances of interphase region and tunnels. The model's accuracy is validated through empirical conductivity measurements of various PCNF samples and extensive parametric analyses. An interphase depth (<em>t</em>) of less than 8 nm renders the composite insulative, whereas peak conductivity of 0.04 S/m is achieved at an interphase depth of 40 nm and interphase conductivity of 400 S/m. These results underscore the significant influence of interphase depth and conductivity on the overall electrical performance of the composites. Furthermore, a CNF length (<em>l</em>) below 13 μm or a contact diameter (<em>d</em>) under 10 nm also results in an insulative composite. Conversely, maximum values of CNF length (80 μm) and contact diameter (40 nm) enhance the composite's conductivity to 0.1 S/m. These findings illustrate the advantageous impact of longer nanofibers and wider tunnels on the electrical conductivity of PCNFs.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"11 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-19DOI: 10.1016/j.polymer.2024.127865
Muhammad Ateeq, Arslan Akbar, Muhammad Shafique
Carbon fiber-reinforced polymer composites are widely used for their corrosion resistance, high strength, stiffness, and lightweight properties. However, the extensive use of carbon fiber generates significant waste at the end of its lifecycle. Recycling technologies can effectively recover carbon fiber from this waste, making it suitable for reuse in various applications. Recently, there has been a growing trend in using recycled carbon fiber as a reinforcement material in polymer matrices, offering a cost-effective alternative to virgin carbon fiber while maintaining excellent mechanical properties. However, most studies focus on the mechanical strength of parts made from recycled and virgin carbon fibers, with less attention given to the environmental impacts of these materials. The primary objective of this study is the comparative analysis of the specimens manufactured using recycled and virgin carbon fiber-reinforced polyamide-12 material based on the mechanical performance, life cycle cost, and environmental impact. The experimental investigations showed that the mechanical performance of the recycled carbon fiber polyamide-12 (rCFRP12) composites are more efficient than the specimens manufactured using the virgin carbon fiber polyamide-12 (vCFRP12) composites such as three-point bending test results show that parts made from rCFRP12 composites achieved a flexural strength of 56.25 MPa, outperforming those made with vCFRP12 (49.9 MPa). Additionally, the recycled composite specimens also exhibited higher tensile strength than their virgin carbon fiber counterparts. The life cycle analysis revealed that samples made with recycled carbon fiber have a lower environmental impact, reducing global warming, ozone depletion, and carcinogenic effects by 11.98% compared to those made with virgin carbon fiber. Additionally, the production cost of recycled carbon fiber is significantly lower than that of virgin carbon fiber.
{"title":"Advancing Circular Economy: Comparative Analysis of Recycled and Virgin Carbon Fiber 3D Printed Composites on Performance and Eco-Efficiency","authors":"Muhammad Ateeq, Arslan Akbar, Muhammad Shafique","doi":"10.1016/j.polymer.2024.127865","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127865","url":null,"abstract":"Carbon fiber-reinforced polymer composites are widely used for their corrosion resistance, high strength, stiffness, and lightweight properties. However, the extensive use of carbon fiber generates significant waste at the end of its lifecycle. Recycling technologies can effectively recover carbon fiber from this waste, making it suitable for reuse in various applications. Recently, there has been a growing trend in using recycled carbon fiber as a reinforcement material in polymer matrices, offering a cost-effective alternative to virgin carbon fiber while maintaining excellent mechanical properties. However, most studies focus on the mechanical strength of parts made from recycled and virgin carbon fibers, with less attention given to the environmental impacts of these materials. The primary objective of this study is the comparative analysis of the specimens manufactured using recycled and virgin carbon fiber-reinforced polyamide-12 material based on the mechanical performance, life cycle cost, and environmental impact. The experimental investigations showed that the mechanical performance of the recycled carbon fiber polyamide-12 (rCFRP12) composites are more efficient than the specimens manufactured using the virgin carbon fiber polyamide-12 (vCFRP12) composites such as three-point bending test results show that parts made from rCFRP12 composites achieved a flexural strength of 56.25 MPa, outperforming those made with vCFRP12 (49.9 MPa). Additionally, the recycled composite specimens also exhibited higher tensile strength than their virgin carbon fiber counterparts. The life cycle analysis revealed that samples made with recycled carbon fiber have a lower environmental impact, reducing global warming, ozone depletion, and carcinogenic effects by 11.98% compared to those made with virgin carbon fiber. Additionally, the production cost of recycled carbon fiber is significantly lower than that of virgin carbon fiber.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"54 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142671048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-19DOI: 10.1016/j.polymer.2024.127860
Elli Bellou, Anastasios C. Manikas, Maria Giovanna Pastore Carbone, Stella Peloni, Christos Tsakonas, Costas Galiotis
Failure of polymers frequently initiates at discontinuities in the material, such as holes and notches, as they constitute points of increased stress concentration. Herein, we propose the use of monolayer graphene produced via Chemical Vapour Deposition to monitor the stress distribution close to a defect in poly(methyl methacrylate). Combining in-situ Raman spectroscopic mapping with tensile tests, the stress/strain distribution around the defect can be probed via monitoring the wavenumber shift of the spectroscopic features of graphene. The measured stress concentration factor of 2.41 is remarkably close to the value derived from Finite Element Analysis, and agrees with other studies in the literature, thus demonstrating that the proposed technique is reliable, and that graphene can accurately sense stress concentration close to a defect, with a sub-micron spatial resolution and a strain resolution of ≈ 60 με.
{"title":"Monitoring stress concentration in polymers with circular notch exploiting graphene-based sensors","authors":"Elli Bellou, Anastasios C. Manikas, Maria Giovanna Pastore Carbone, Stella Peloni, Christos Tsakonas, Costas Galiotis","doi":"10.1016/j.polymer.2024.127860","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127860","url":null,"abstract":"Failure of polymers frequently initiates at discontinuities in the material, such as holes and notches, as they constitute points of increased stress concentration. Herein, we propose the use of monolayer graphene produced via Chemical Vapour Deposition to monitor the stress distribution close to a defect in poly(methyl methacrylate). Combining in-situ Raman spectroscopic mapping with tensile tests, the stress/strain distribution around the defect can be probed via monitoring the wavenumber shift of the spectroscopic features of graphene. The measured stress concentration factor of 2.41 is remarkably close to the value derived from Finite Element Analysis, and agrees with other studies in the literature, thus demonstrating that the proposed technique is reliable, and that graphene can accurately sense stress concentration close to a defect, with a sub-micron spatial resolution and a strain resolution of ≈ 60 με.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"69 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142671050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-performance epoxy materials often necessitate curing at high-temperature, which can lead to defects, brittleness, deformation and processing difficulties. In this paper, the modifier sulfhydryl hyperbranched polysiloxane (HSiSH) was fabricated by the “one-pot” method. And investigated the effect of HSiSH on the curing temperature, mechanical and thermal properties of epoxy resin. The epoxy with the addition of 2.0 wt% HSiSH showcased superior comprehensive properties, including flexural strength of 159.37 MPa, impact strength of 24.77 kJ/m2, and tensile shear strength of 14.02 MPa, as well as the thermal properties are improved. Moreover, the presence of 2 wt% HSiSH can facilitate the curing process reducing the apparent activation energy by 12.25%. The highly branched topology, chain entanglement, "rigid-flexible" -Si-O-C- segment and active groups improve the strength and toughness of the material. Simultaneously, the numerous reactive groups within HSiSH actively participate in the curing reaction, thereby enhancing the adhesion between the resin and the substrate surface which increasing the bonding performance of the adhesive. This study lays a solid theoretical foundation for developing high-performance epoxy resins cured at lower and moderate temperatures.
{"title":"Epoxy resins containing sulfhydryl hyperbranched polysiloxane with desirable mechanical properties and lower curing temperature","authors":"Feifei Wang, Junyan Yao, Kaiming Yang, Bingrui Shi, Zhenlong Zhang, Weixu Feng, Hongxia Yan","doi":"10.1016/j.polymer.2024.127859","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127859","url":null,"abstract":"High-performance epoxy materials often necessitate curing at high-temperature, which can lead to defects, brittleness, deformation and processing difficulties. In this paper, the modifier sulfhydryl hyperbranched polysiloxane (HSiSH) was fabricated by the “one-pot” method. And investigated the effect of HSiSH on the curing temperature, mechanical and thermal properties of epoxy resin. The epoxy with the addition of 2.0 wt% HSiSH showcased superior comprehensive properties, including flexural strength of 159.37 MPa, impact strength of 24.77 kJ/m<sup>2</sup>, and tensile shear strength of 14.02 MPa, as well as the thermal properties are improved. Moreover, the presence of 2 wt% HSiSH can facilitate the curing process reducing the apparent activation energy by 12.25%. The highly branched topology, chain entanglement, \"rigid-flexible\" -Si-O-C- segment and active groups improve the strength and toughness of the material. Simultaneously, the numerous reactive groups within HSiSH actively participate in the curing reaction, thereby enhancing the adhesion between the resin and the substrate surface which increasing the bonding performance of the adhesive. This study lays a solid theoretical foundation for developing high-performance epoxy resins cured at lower and moderate temperatures.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"99 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the flexural strength of 3D-printed nylon-carbon reinforced composite specimens, highlighting the impact of infill density and layer height on mechanical performance. The findings indicate that a printing layer height of 0.10 mm with 100% infill density exhibits the highest flexural strength, supporting a maximum load of 127 N, compared to 76.7 N at 50% infill density. Microstructural study has clearly illustrated the structural distortion, revealing that a rise in layer height correlates with an escalation in structural distortion. An Artificial Neural Network (ANN) model is thus utilized to achieve high predictive accuracy in order to predict flexural behaviour. R-values above 0.98 are obtained across training, validation, and test datasets, indicating that ANN-based modelling may be able to facilitate quick optimization of 3D printing parameters for high-performance applications. These findings establish carbon-reinforced nylon as a formidable competitor for use in industries such as aerospace and automotive, where strength and durability are important.
本研究调查了三维打印尼龙-碳增强复合材料试样的抗弯强度，突出了填充密度和层高对机械性能的影响。研究结果表明，打印层高为 0.10 毫米、填充密度为 100% 的试样具有最高的抗弯强度，可承受 127 牛顿的最大载荷，而填充密度为 50% 的试样仅能承受 76.7 牛顿的载荷。微观结构研究清楚地表明了结构的变形，揭示了层高的增加与结构变形的升级相关。因此，利用人工神经网络（ANN）模型实现了高预测精度，以预测弯曲行为。训练、验证和测试数据集的 R 值均高于 0.98，这表明基于 ANN 的建模可能有助于快速优化高性能应用的 3D 打印参数。这些研究结果确立了碳增强尼龙在航空航天和汽车等对强度和耐用性要求较高的行业中的强大竞争力。
{"title":"Evaluation of Flexural strength of 3D-Printed Nylon with carbon reinforcement: An experimental validation using ANN","authors":"Vijay Kumar, Dhinakaran Veeman, Murugan Vellaisamy, Vikrant Singh","doi":"10.1016/j.polymer.2024.127854","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127854","url":null,"abstract":"This study investigates the flexural strength of 3D-printed nylon-carbon reinforced composite specimens, highlighting the impact of infill density and layer height on mechanical performance. The findings indicate that a printing layer height of 0.10 mm with 100% infill density exhibits the highest flexural strength, supporting a maximum load of 127 N, compared to 76.7 N at 50% infill density. Microstructural study has clearly illustrated the structural distortion, revealing that a rise in layer height correlates with an escalation in structural distortion. An Artificial Neural Network (ANN) model is thus utilized to achieve high predictive accuracy in order to predict flexural behaviour. R-values above 0.98 are obtained across training, validation, and test datasets, indicating that ANN-based modelling may be able to facilitate quick optimization of 3D printing parameters for high-performance applications. These findings establish carbon-reinforced nylon as a formidable competitor for use in industries such as aerospace and automotive, where strength and durability are important.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"22 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142671049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N-bromosuccinimide (NBS) has notable selectivity for brominating aromatic compounds with alkyl side chains. This study employs NBS in lieu of liquid bromine to prepare spinnable isotropic pitch derived from ethylene tar pitch (ETP) using a selective photobromination-debromination approach. The prepared isotropic pitches were then utilized to fabricate isotropic pitch-based carbon fibers (IPCFs) through a process involving melt spinning, oxidative stabilization, and subsequent carbonization. As the amount of NBS added increases in the photobromination stage, the softening point, pitch yield, average molecular weight, and degree of polymerization of the resulting isotropic pitch gradually increase, whereas its spinnability first improves but then decreases. Compared with the isotropic pitch manufactured through thermal polymerization alone, the isotropic pitch that undergo photobromination–debromination exhibits a more linear molecular structure formed by methylene/ethylidene-bridged aromatic units. This molecular structure enhances its spinnability, significantly improving the mechanical performance of the resulting IPCFs. The isotropic pitch produced with 15 wt% NBS during photobromination demonstrates exceptional spinnability, yielding carbon fibers with excellent mechanical characteristics. These fibers exhibit a tensile strength of 1333 MPa, Young’s modulus of 64 GPa, and an elongation property of 2.4%. This work provides a new method for the high value-added utilization of ET by controlling the molecular structure of the pitch precursor.
{"title":"Controllable preparation of spinnable isotropic pitches for carbon fibers with high tensile strength from low-cost ethylene tar pitch by a selective photobromination–debromination method","authors":"Ganggang Zhai, Jianguang Guo, Yongsheng Tian, Guanming Yuan, Ye Cong, Baoliu Li, Qin Zhang, Yongting Chen, Xuanke Li, Zhijun Dong","doi":"10.1016/j.polymer.2024.127862","DOIUrl":"https://doi.org/10.1016/j.polymer.2024.127862","url":null,"abstract":"N-bromosuccinimide (NBS) has notable selectivity for brominating aromatic compounds with alkyl side chains. This study employs NBS in lieu of liquid bromine to prepare spinnable isotropic pitch derived from ethylene tar pitch (ETP) using a selective photobromination-debromination approach. The prepared isotropic pitches were then utilized to fabricate isotropic pitch-based carbon fibers (IPCFs) through a process involving melt spinning, oxidative stabilization, and subsequent carbonization. As the amount of NBS added increases in the photobromination stage, the softening point, pitch yield, average molecular weight, and degree of polymerization of the resulting isotropic pitch gradually increase, whereas its spinnability first improves but then decreases. Compared with the isotropic pitch manufactured through thermal polymerization alone, the isotropic pitch that undergo photobromination–debromination exhibits a more linear molecular structure formed by methylene/ethylidene-bridged aromatic units. This molecular structure enhances its spinnability, significantly improving the mechanical performance of the resulting IPCFs. The isotropic pitch produced with 15 wt% NBS during photobromination demonstrates exceptional spinnability, yielding carbon fibers with excellent mechanical characteristics. These fibers exhibit a tensile strength of 1333 MPa, Young’s modulus of 64 GPa, and an elongation property of 2.4%. This work provides a new method for the high value-added utilization of ET by controlling the molecular structure of the pitch precursor.","PeriodicalId":405,"journal":{"name":"Polymer","volume":"2 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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