Zhenyu Guo, Weiqiang Song, Xueqin Wei, Yu Feng, Yixuan Song, Zidong Guo, Wenxi Cheng, Wei Miao, Bo Cheng, Shiping Song
Abstract The ratio of poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and calcium carbonate (CaCO3) fillers in PLA/PBAT/CaCO3 composites was set at 90/10/5, 70/30/5, and 30/70/5. The effect of nano- and micro-CaCO3 on the melting and crystallization performance of the composites was investigated by differential scanning calorimetry. PLA crystallization was related to the PLA and PBAT ratio, cooling rate, and CaCO3 particle size in PLA/PBAT/CaCO3 composites. Nano-CaCO3 prevented the crystallization of PLA in PLA/PBAT/CaCO3 90/10/5 and 70/30/5 but did not prevent the crystallization of PLA in PLA/PBAT/CaCO3 30/70/5. Unlike nano-CaCO3, micro-CaCO3 did not prevent PLA crystallization regardless of the PLA and PBAT ratio. Nano- and micro-CaCO3 enhance PLA90 and PLA70 to some extent, due to the aggregation and dissociation of the CaCO3 filler in polylactic acid. But nano- and micro-CaCO3 improved the mechanical properties of PLA30 several times, due to the good compatibility of the CaCO3 filler and PBAT. The effect of nano-CaCO3 and micro-CaCO3 on the mechanical properties of PLA/PBAT/CaCO3 composites had no significant difference.
{"title":"Effect of matrix composition on the performance of calcium carbonate filled poly(lactic acid)/poly(butylene adipate-co-terephthalate) composites","authors":"Zhenyu Guo, Weiqiang Song, Xueqin Wei, Yu Feng, Yixuan Song, Zidong Guo, Wenxi Cheng, Wei Miao, Bo Cheng, Shiping Song","doi":"10.1515/epoly-2023-0026","DOIUrl":"https://doi.org/10.1515/epoly-2023-0026","url":null,"abstract":"Abstract The ratio of poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and calcium carbonate (CaCO3) fillers in PLA/PBAT/CaCO3 composites was set at 90/10/5, 70/30/5, and 30/70/5. The effect of nano- and micro-CaCO3 on the melting and crystallization performance of the composites was investigated by differential scanning calorimetry. PLA crystallization was related to the PLA and PBAT ratio, cooling rate, and CaCO3 particle size in PLA/PBAT/CaCO3 composites. Nano-CaCO3 prevented the crystallization of PLA in PLA/PBAT/CaCO3 90/10/5 and 70/30/5 but did not prevent the crystallization of PLA in PLA/PBAT/CaCO3 30/70/5. Unlike nano-CaCO3, micro-CaCO3 did not prevent PLA crystallization regardless of the PLA and PBAT ratio. Nano- and micro-CaCO3 enhance PLA90 and PLA70 to some extent, due to the aggregation and dissociation of the CaCO3 filler in polylactic acid. But nano- and micro-CaCO3 improved the mechanical properties of PLA30 several times, due to the good compatibility of the CaCO3 filler and PBAT. The effect of nano-CaCO3 and micro-CaCO3 on the mechanical properties of PLA/PBAT/CaCO3 composites had no significant difference.","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":"45460502","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 Damage to polymer adhesives is one of the most common reasons for structural integrity damage of composite solid propellants. The introduction of self-repairing technology into the adhesive is expected to solve this problem. However, at low temperatures, the self-repairing and mechanical properties of the materials are greatly impaired, thereby limiting the application of self-repairing adhesives in composite solid propellants. In this study, based on the dual synergistic crosslinking strategy, a polyurethane adhesive exhibiting excellent self-healing and mechanical properties at low temperatures was successfully prepared. The adhesive exhibited high self-repairing efficiency and ultra-long elongation at break at low temperatures. Specifically, at a low temperature of −40°C, the self-repair efficiency was over 70% and the elongation at break was over 1,400%, which were much higher than the results of the control group. Moreover, the strength was comparable to that of the control group. This polyurethane adhesive shows excellent self-healing and mechanical properties at low temperatures and is expected to provide the strong self-healing ability and mechanical properties for composite solid propellants, alleviating the problem of structural integrity damage. Graphical abstract A self-healable HEPU-Zn polyurethane adhesive was prepared. Through the dual synergetic crosslinking strategy, HEPU-Zn was endowed with excellent mechanical and self-healing properties at low temperatures.
{"title":"Low-temperature self-healing polyurethane adhesives via dual synergetic crosslinking strategy","authors":"Yu Zhang, Jian Zheng, Xiao Zhang, Yahao Liu","doi":"10.1515/epoly-2022-0083","DOIUrl":"https://doi.org/10.1515/epoly-2022-0083","url":null,"abstract":"Abstract Damage to polymer adhesives is one of the most common reasons for structural integrity damage of composite solid propellants. The introduction of self-repairing technology into the adhesive is expected to solve this problem. However, at low temperatures, the self-repairing and mechanical properties of the materials are greatly impaired, thereby limiting the application of self-repairing adhesives in composite solid propellants. In this study, based on the dual synergistic crosslinking strategy, a polyurethane adhesive exhibiting excellent self-healing and mechanical properties at low temperatures was successfully prepared. The adhesive exhibited high self-repairing efficiency and ultra-long elongation at break at low temperatures. Specifically, at a low temperature of −40°C, the self-repair efficiency was over 70% and the elongation at break was over 1,400%, which were much higher than the results of the control group. Moreover, the strength was comparable to that of the control group. This polyurethane adhesive shows excellent self-healing and mechanical properties at low temperatures and is expected to provide the strong self-healing ability and mechanical properties for composite solid propellants, alleviating the problem of structural integrity damage. Graphical abstract A self-healable HEPU-Zn polyurethane adhesive was prepared. Through the dual synergetic crosslinking strategy, HEPU-Zn was endowed with excellent mechanical and self-healing properties at low temperatures.","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":"47249716","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 thermal decomposition behavior of polyacrylate pressure-sensitive adhesive (PSA) at heating rates of 4, 6, 8, and 10 K·min−1 was measured by thermogravimetric analysis (TGA). The kinetic parameters for thermal decomposition reaction of the polyacrylate adhesive were obtained from TG profile by differential method and integral method (Kissinger, general integral, MacCallum–Tanner, Šatava–Šesták, Agrawal, and Flynn–Wall–Ozawa), the results show that the main decomposition stage of the polyacrylate adhesive starts at 301°C and its activation energy is 142.68 kJ·mol−1, the pre exponential factor is 109.55, the decomposition mechanism obeys Avrami–Erofeev equation and its decomposition kinetic equation can be expressed as: dα/dT = (109.55/β)[(1 − α)/2][−ln(1 − α)]−1exp(−1.7161 × 104/T). The storage life of PSA at 25°C was predicted to be about 19 years by isoconversional method.
{"title":"Thermal decomposition reaction kinetics and storage life prediction of polyacrylate pressure-sensitive adhesive","authors":"Bing‐yuan Li, Yingzi Li, Zongwen Tong, Hongbin Yang, Sen-Sen Du, Zhuozhen Zhang","doi":"10.1515/epoly-2022-0089","DOIUrl":"https://doi.org/10.1515/epoly-2022-0089","url":null,"abstract":"Abstract The thermal decomposition behavior of polyacrylate pressure-sensitive adhesive (PSA) at heating rates of 4, 6, 8, and 10 K·min−1 was measured by thermogravimetric analysis (TGA). The kinetic parameters for thermal decomposition reaction of the polyacrylate adhesive were obtained from TG profile by differential method and integral method (Kissinger, general integral, MacCallum–Tanner, Šatava–Šesták, Agrawal, and Flynn–Wall–Ozawa), the results show that the main decomposition stage of the polyacrylate adhesive starts at 301°C and its activation energy is 142.68 kJ·mol−1, the pre exponential factor is 109.55, the decomposition mechanism obeys Avrami–Erofeev equation and its decomposition kinetic equation can be expressed as: dα/dT = (109.55/β)[(1 − α)/2][−ln(1 − α)]−1exp(−1.7161 × 104/T). The storage life of PSA at 25°C was predicted to be about 19 years by isoconversional method.","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":"48057034","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 To optimize the surface performance of the composites of polyamide 66 and continuous glass fiber (50/50, weight ratio), poly(hexamethylene isoftalamide-co-terephthalamide) (PA6I-6T) was introduced. The composites were prepared by a twin-screw extruder, and the effect of PA6I-6T on the thermal and mechanical properties, as well as surface appearance was investigated. The results showed that the crystallization temperature and the melting point of the composites decreased with increasing the amount of PA6I-6T. The Jeziorny method proved that the presence of PA6I-6T did not change the nucleation mode and the crystal growth of PA66 in the hybrid matrix, and the Mo method revealed that the crystallization rate of PA66 decreased first and then increased with the increase of the PA6I-6T content. The reduction in the “floating fiber” on the surface of the composites was attributed to the decrease of the crystallization rate of PA66 in the presence of PA6I-6T. It was shown that the composites with smooth surface had a large melt flow index. Moreover, the composites with high content of PA6I-6T had low heat deformation temperatures. The mechanical properties of the composites did not change significantly with the increase of the PA6I-6T content. Scanning electron microscope (SEM) images revealed that glass fiber was evenly distributed in the matrix and strongly oriented parallel to the injection direction.
{"title":"Effect of matrix composition on properties of polyamide 66/polyamide 6I-6T composites with high content of continuous glass fiber for optimizing surface performance","authors":"Jiaxiang Xie","doi":"10.1515/epoly-2022-8111","DOIUrl":"https://doi.org/10.1515/epoly-2022-8111","url":null,"abstract":"Abstract To optimize the surface performance of the composites of polyamide 66 and continuous glass fiber (50/50, weight ratio), poly(hexamethylene isoftalamide-co-terephthalamide) (PA6I-6T) was introduced. The composites were prepared by a twin-screw extruder, and the effect of PA6I-6T on the thermal and mechanical properties, as well as surface appearance was investigated. The results showed that the crystallization temperature and the melting point of the composites decreased with increasing the amount of PA6I-6T. The Jeziorny method proved that the presence of PA6I-6T did not change the nucleation mode and the crystal growth of PA66 in the hybrid matrix, and the Mo method revealed that the crystallization rate of PA66 decreased first and then increased with the increase of the PA6I-6T content. The reduction in the “floating fiber” on the surface of the composites was attributed to the decrease of the crystallization rate of PA66 in the presence of PA6I-6T. It was shown that the composites with smooth surface had a large melt flow index. Moreover, the composites with high content of PA6I-6T had low heat deformation temperatures. The mechanical properties of the composites did not change significantly with the increase of the PA6I-6T content. Scanning electron microscope (SEM) images revealed that glass fiber was evenly distributed in the matrix and strongly oriented parallel to the injection direction.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"23 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67351868","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 novel homogenous braid-reinforced (HBR) poly (p-phenylene terephthamide) (PPTA) hollow fiber membrane was prepared in this study. The effects of PPTA concentration on the morphologies and properties of the membranes were further investigated. The results showed that when the PPTA concentration was 2.0 wt%, the cross-sectional morphology of satisfactory interfacial bonding was achieved and the permeation was still maintained at about 200 (L·m−2·h−1) after ultrasonic vibration. In addition, the tensile force exceeded 600 N, which indicated that the homogeneous effect effectively improved the poor mechanical properties and interfacial bonding. In addition, the HBR PPTA hollow fiber membranes were applied to simulate the membrane bioreactor system to explore the control factors of membrane fouling. The results demonstrated that the average removal of total phosphorus and NH4 +–N was above 49% and 96%, respectively; meanwhile, the operating time was up to 120 days. Furthermore, it was easier to nearly remove the pollutants by chemical cleaning.
{"title":"Preparation and performance of homogenous braids-reinforced poly (p-phenylene terephthamide) hollow fiber membranes","authors":"Chun Wang, Dinghe Yan, Shubin Song, Jingjing Yan, Haolong Xue, Changfan Xiao","doi":"10.1515/epoly-2023-0062","DOIUrl":"https://doi.org/10.1515/epoly-2023-0062","url":null,"abstract":"Abstract A novel homogenous braid-reinforced (HBR) poly (p-phenylene terephthamide) (PPTA) hollow fiber membrane was prepared in this study. The effects of PPTA concentration on the morphologies and properties of the membranes were further investigated. The results showed that when the PPTA concentration was 2.0 wt%, the cross-sectional morphology of satisfactory interfacial bonding was achieved and the permeation was still maintained at about 200 (L·m−2·h−1) after ultrasonic vibration. In addition, the tensile force exceeded 600 N, which indicated that the homogeneous effect effectively improved the poor mechanical properties and interfacial bonding. In addition, the HBR PPTA hollow fiber membranes were applied to simulate the membrane bioreactor system to explore the control factors of membrane fouling. The results demonstrated that the average removal of total phosphorus and NH4 +–N was above 49% and 96%, respectively; meanwhile, the operating time was up to 120 days. Furthermore, it was easier to nearly remove the pollutants by chemical cleaning.","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":"45237755","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}
Liu Yang, X. Dai, Xuan Zhao, Feng Liu, Yunhui Xu, Yanqiu Wang
Abstract Fatigue failure, commonly encountered in rubber materials, is a critical issue. In this study, the compression fatigue tests of filled styrene-butadiene rubber (SBR) under different loading conditions were performed, applying cylindrical specimens. A stress–strain curve and modulus drop curves were generated by nine fatigue loading cases, covering different R ratios in the range of 0 < R < 1. The temperature variation in the process of compression fatigue was explored. Three different approaches were applied to investigate the fatigue life of the SBR (it is used twice hence abbreviation should be used) vulcanizates. These methods were validated in assessing the fatigue failure of the specimens. According to the experimental fatigue life, a fatigue life prediction model based on strain amplitude as the damage parameter was established. The results demonstrated that both R ratio and strain amplitude could affect the fatigue life. For all the loading cases, the fatigue life generally increases with the increase of R ratio. Under the compression loading condition, the narrower range of strain and the lower mean strain are beneficial to the fatigue resistance of rubbers, which also indicates a larger pre-load provides much higher fatigue resistance. During the fatigue loading, the temperature rises rapidly until it reaches a peak value, then drops slightly, and finally reaches a plateau.
橡胶材料中常见的疲劳失效是一个重要问题。采用圆柱形试样，对填充丁苯橡胶(SBR)进行了不同加载条件下的压缩疲劳试验。在0 < R < 1范围内不同R比下的9种疲劳加载情况下，生成应力-应变曲线和模量下降曲线。探讨了压缩疲劳过程中的温度变化规律。采用三种不同的方法研究了SBR(使用了两次，因此应使用缩写)硫化橡胶的疲劳寿命。这些方法在试件疲劳破坏评估中得到了验证。根据试验疲劳寿命，建立了以应变幅值为损伤参数的疲劳寿命预测模型。结果表明，R比和应变幅值对疲劳寿命都有影响。在各种载荷情况下，随着R比的增大，疲劳寿命普遍增加。在压缩加载条件下，较窄的应变范围和较低的平均应变有利于橡胶的抗疲劳性能，这也表明较大的预载荷可以提供更高的抗疲劳性能。在疲劳加载过程中，温度迅速上升，达到峰值后略有下降，最后达到平台期。
{"title":"Loading conditions impact on the compression fatigue behavior of filled styrene butadiene rubber","authors":"Liu Yang, X. Dai, Xuan Zhao, Feng Liu, Yunhui Xu, Yanqiu Wang","doi":"10.1515/epoly-2022-8091","DOIUrl":"https://doi.org/10.1515/epoly-2022-8091","url":null,"abstract":"Abstract Fatigue failure, commonly encountered in rubber materials, is a critical issue. In this study, the compression fatigue tests of filled styrene-butadiene rubber (SBR) under different loading conditions were performed, applying cylindrical specimens. A stress–strain curve and modulus drop curves were generated by nine fatigue loading cases, covering different R ratios in the range of 0 < R < 1. The temperature variation in the process of compression fatigue was explored. Three different approaches were applied to investigate the fatigue life of the SBR (it is used twice hence abbreviation should be used) vulcanizates. These methods were validated in assessing the fatigue failure of the specimens. According to the experimental fatigue life, a fatigue life prediction model based on strain amplitude as the damage parameter was established. The results demonstrated that both R ratio and strain amplitude could affect the fatigue life. For all the loading cases, the fatigue life generally increases with the increase of R ratio. Under the compression loading condition, the narrower range of strain and the lower mean strain are beneficial to the fatigue resistance of rubbers, which also indicates a larger pre-load provides much higher fatigue resistance. During the fatigue loading, the temperature rises rapidly until it reaches a peak value, then drops slightly, and finally reaches a plateau.","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":"42417091","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}
M. Tan, C. Yeoh, P. Teh, N. Rahim, Cheah Chie Song, C. Voon
Abstract This work aimed to study the effect of zinc oxide (ZnO) filler suspension on the mechanical, electrical, and thermal properties of polylactic acid (PLA)/ZnO and cPLA/ZnO. Fused deposition modelling, one of the additive manufacturing methods, was used to fabricate the PLA specimen. PLA was used as the main material in this project, and the ZnO suspension was added during the printing process. The speed of the dispenser (low speed = 1,000 rpm, medium speed = 1,400 rpm, and high speed = 1,800 rpm) was the parameter that was varied to control the filler content of the composite. All the samples underwent a tensile test to determine the mechanical properties, followed by the scanning electron microscopy (SEM) test to analyse the fracture surface properties of the tensile test. SEM observations showed the PLA samples’ inherent smooth appearance, but the PLA/ZnO composite showed a rougher surface. PLA and cPLA composites showed an enhanced storage modulus but lower loss modulus than the pure samples. Because of the high thermal and electrical conductivity of carbon black and ZnO, cPLA composites had higher electrical and thermal conductivity than PLA composites.
{"title":"Effect of zinc oxide suspension on the overall filler content of the PLA/ZnO composites and cPLA/ZnO composites","authors":"M. Tan, C. Yeoh, P. Teh, N. Rahim, Cheah Chie Song, C. Voon","doi":"10.1515/epoly-2022-8113","DOIUrl":"https://doi.org/10.1515/epoly-2022-8113","url":null,"abstract":"Abstract This work aimed to study the effect of zinc oxide (ZnO) filler suspension on the mechanical, electrical, and thermal properties of polylactic acid (PLA)/ZnO and cPLA/ZnO. Fused deposition modelling, one of the additive manufacturing methods, was used to fabricate the PLA specimen. PLA was used as the main material in this project, and the ZnO suspension was added during the printing process. The speed of the dispenser (low speed = 1,000 rpm, medium speed = 1,400 rpm, and high speed = 1,800 rpm) was the parameter that was varied to control the filler content of the composite. All the samples underwent a tensile test to determine the mechanical properties, followed by the scanning electron microscopy (SEM) test to analyse the fracture surface properties of the tensile test. SEM observations showed the PLA samples’ inherent smooth appearance, but the PLA/ZnO composite showed a rougher surface. PLA and cPLA composites showed an enhanced storage modulus but lower loss modulus than the pure samples. Because of the high thermal and electrical conductivity of carbon black and ZnO, cPLA composites had higher electrical and thermal conductivity than PLA composites.","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":"49627514","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}
I. Gustian, Anastasia Simalango, D. A. Triawan, Agus Martono Hadi Putranto, Asdim
Abstract In this work, proton-conducting membranes have been prepared by entrapping human nail keratin in bacterial cellulose at different mass ratios. Bacterial cellulose was obtained by fermenting coconut water with the Acetobacter xylinum bacterium, and keratin was obtained from human nails. The membrane is produced by the blending and heating process at a temperature of 40°C. FTIR spectroscopy showed the interaction between bacterial cellulose and human nail keratin at a peak area of 3,000–2,000 cm−1. The X-ray diffraction analysis has confirmed the effect of keratin mass on the diffractogram pattern of the membranes. The maximum proton conductivity has been measured as 4.572 × 10−5 S·cm−1 at 25°C and produces a degree of swelling of 32.50% for a mass ratio of bacterial cellulose/human nail keratin 4:1.
{"title":"Synthesis and characterization of proton-conducting membranes based on bacterial cellulose and human nail keratin","authors":"I. Gustian, Anastasia Simalango, D. A. Triawan, Agus Martono Hadi Putranto, Asdim","doi":"10.1515/epoly-2023-0040","DOIUrl":"https://doi.org/10.1515/epoly-2023-0040","url":null,"abstract":"Abstract In this work, proton-conducting membranes have been prepared by entrapping human nail keratin in bacterial cellulose at different mass ratios. Bacterial cellulose was obtained by fermenting coconut water with the Acetobacter xylinum bacterium, and keratin was obtained from human nails. The membrane is produced by the blending and heating process at a temperature of 40°C. FTIR spectroscopy showed the interaction between bacterial cellulose and human nail keratin at a peak area of 3,000–2,000 cm−1. The X-ray diffraction analysis has confirmed the effect of keratin mass on the diffractogram pattern of the membranes. The maximum proton conductivity has been measured as 4.572 × 10−5 S·cm−1 at 25°C and produces a degree of swelling of 32.50% for a mass ratio of bacterial cellulose/human nail keratin 4:1.","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":"43196208","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}
K. Su, Ruolin Han, Zheng Zhou, Guang-xin Chen, Qifang Li
Abstract Numerous studies have shown that ceramic materials with high dielectric constants and low dielectric losses can be obtained using donor–acceptor-doped TiO2. In this study, (La + Nb)-co-doped TiO2 [(La0.5Nb0.5) x Ti1−x O2 x-LNTO] ceramic powders were prepared using the sol–gel method. XRD demonstrates that LNTO is a rutile phase, and the lattice parameters change after doping, while X-ray photoelectron spectroscopy explains the doping mechanism, with doping of TiO2 producing oxygen vacancies and Ti3+, which form defective dipoles with the dopant ions to increase the dielectric constant of the material. The dielectric properties were investigated by physically co-blending x-LNTO/polyvinylidene difluoride (PVDF) composites. Compared with the TiO2/PVDF composite, the dielectric properties of the x-LNTO/PVDF composite were more excellent. The dielectric constant of 5-LNTO/PVDF reached 36.96, which was higher than that of the TiO2/PVDF composite (19.49) at a filler addition of 60 wt% and a frequency of 1 kHz.
{"title":"Preparation of (La + Nb)-co-doped TiO2 and its polyvinylidene difluoride composites with high dielectric constants","authors":"K. Su, Ruolin Han, Zheng Zhou, Guang-xin Chen, Qifang Li","doi":"10.1515/epoly-2023-0021","DOIUrl":"https://doi.org/10.1515/epoly-2023-0021","url":null,"abstract":"Abstract Numerous studies have shown that ceramic materials with high dielectric constants and low dielectric losses can be obtained using donor–acceptor-doped TiO2. In this study, (La + Nb)-co-doped TiO2 [(La0.5Nb0.5) x Ti1−x O2 x-LNTO] ceramic powders were prepared using the sol–gel method. XRD demonstrates that LNTO is a rutile phase, and the lattice parameters change after doping, while X-ray photoelectron spectroscopy explains the doping mechanism, with doping of TiO2 producing oxygen vacancies and Ti3+, which form defective dipoles with the dopant ions to increase the dielectric constant of the material. The dielectric properties were investigated by physically co-blending x-LNTO/polyvinylidene difluoride (PVDF) composites. Compared with the TiO2/PVDF composite, the dielectric properties of the x-LNTO/PVDF composite were more excellent. The dielectric constant of 5-LNTO/PVDF reached 36.96, which was higher than that of the TiO2/PVDF composite (19.49) at a filler addition of 60 wt% and a frequency of 1 kHz.","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":"46957052","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 This study deals with the preparation and characterization of novel composites accomplished by filling hydroxyethylcellulose with several amounts of bentonite. Molecular modeling enabled understanding the conformational and physicochemical features, which are responsible for the chemical reactivity parameters. Rheological analyses are made to investigate the effect of the polymer loading on the shear flow behavior. The morphology and homogeneity of each system is explored via optical microscopy. The band gap of the samples is slightly reduced by the addition of the bio-filler in the cellulosic medium, as indicated by UV-VIS spectral data. The dielectric response of these materials is extracted from refractometry experiments at several wavelengths. The electric energy density was achieved based on the dielectric properties determined at high and low frequencies. The outcome of this study offers new ways to produce alternative dielectric eco-materials having a good potential of accumulating electrical energy, as demanded for capacitor devices.
{"title":"Bentonite/hydroxyethylcellulose as eco-dielectrics with potential utilization in energy storage","authors":"Andreea Irina Barzic, Iuliana Stoica, Mihai Asandulesa, Raluca Marinica Albu, Bogdan Oprisan","doi":"10.1515/epoly-2023-0073","DOIUrl":"https://doi.org/10.1515/epoly-2023-0073","url":null,"abstract":"Abstract This study deals with the preparation and characterization of novel composites accomplished by filling hydroxyethylcellulose with several amounts of bentonite. Molecular modeling enabled understanding the conformational and physicochemical features, which are responsible for the chemical reactivity parameters. Rheological analyses are made to investigate the effect of the polymer loading on the shear flow behavior. The morphology and homogeneity of each system is explored via optical microscopy. The band gap of the samples is slightly reduced by the addition of the bio-filler in the cellulosic medium, as indicated by UV-VIS spectral data. The dielectric response of these materials is extracted from refractometry experiments at several wavelengths. The electric energy density was achieved based on the dielectric properties determined at high and low frequencies. The outcome of this study offers new ways to produce alternative dielectric eco-materials having a good potential of accumulating electrical energy, as demanded for capacitor devices.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"36 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":"135103403","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}
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