It is urgent to acquire a feasible strategy for balancing the strength and ductility of polylactic acid (PLA) in the application of biodegradable packaging materials. In this study, a new strategy is provided to enhance mechanical, barrier, and optical properties by the synergetic effect of manipulating the amorphous chain entanglement network and constructing the “nano- walls” of highly aligned calcium sulfate whisker (CSW), zinc phenylphosphonate (PPZn), and well-defined crystals via biaxial stretching. PPZn is verified as a nucleator to accelerate the crystallization rate and induce α-form crystals. CSW is regarded as a supporting skeleton to strengthen the entanglement density of the chain network. The extensional stress, which is induced by biaxial stretching, regulates the amorphous chain entanglement network and facilitates the chain orientation. As a result, the synergetic structure displays an outstanding capacity for improving the mechanical, barrier, and optical properties of PLA. Compared to the PLA film, the biaxially stretched PLA/PPZn/CSW films exhibit high strength, excellent ductility, and superior crystallinity, which are significantly increased by up to 53.2%, 381.3%, and 748.9%, respectively. And their gas and water vapor barrier properties remarkably increased by 65.39% and 73.11%, respectively. The optical property with a haze value of 52.4% and good transmittance of 97.4% is also obtained via the synergetic effect. With the excellent comprehensive properties of PLA films, this new strategy explores a new field in environmentally friendly packaging materials and is relevant to future work.
{"title":"Robust biaxially stretchable polylactic acid films based on the highly oriented chain network and “nano-walls” containing zinc phenylphosphonate and calcium sulfate whisker: Superior mechanical, barrier, and optical properties","authors":"Shi-Juan Ding, Ling-Na Cui, Yue-Jun Liu","doi":"10.1515/epoly-2024-0032","DOIUrl":"https://doi.org/10.1515/epoly-2024-0032","url":null,"abstract":"It is urgent to acquire a feasible strategy for balancing the strength and ductility of polylactic acid (PLA) in the application of biodegradable packaging materials. In this study, a new strategy is provided to enhance mechanical, barrier, and optical properties by the synergetic effect of manipulating the amorphous chain entanglement network and constructing the “nano- walls” of highly aligned calcium sulfate whisker (CSW), zinc phenylphosphonate (PPZn), and well-defined crystals via biaxial stretching. PPZn is verified as a nucleator to accelerate the crystallization rate and induce α-form crystals. CSW is regarded as a supporting skeleton to strengthen the entanglement density of the chain network. The extensional stress, which is induced by biaxial stretching, regulates the amorphous chain entanglement network and facilitates the chain orientation. As a result, the synergetic structure displays an outstanding capacity for improving the mechanical, barrier, and optical properties of PLA. Compared to the PLA film, the biaxially stretched PLA/PPZn/CSW films exhibit high strength, excellent ductility, and superior crystallinity, which are significantly increased by up to 53.2%, 381.3%, and 748.9%, respectively. And their gas and water vapor barrier properties remarkably increased by 65.39% and 73.11%, respectively. The optical property with a haze value of 52.4% and good transmittance of 97.4% is also obtained via the synergetic effect. With the excellent comprehensive properties of PLA films, this new strategy explores a new field in environmentally friendly packaging materials and is relevant to future work.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"101 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141190471","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}
The application of bio-based solvents for living radical polymerization has been a hot topic in recent year. In this article, γ-valerolactone (GVL), a bio-based solvent as green media for ARGET atom transfer radical polymerization (ATRP) of styrene (St) were investigated. We first conducted polymerization of St in γ-valerolactone using copper(ii) bromide as the catalyst, tris(2-pyridylmethyl) amine as the ligand, and only sodium ascorbate as reducing agent. The polymerization achieved moderate conversion; however, the controllability of polymerization was not very good, providing a polymer with a broad molecular weight distribution (Mw/Mn> 1.30). When sodium carbonate is introduced, excellent results were obtained providing high yields and low Mw/Mn values under very low catalyst usage (∼5 ppm). 1H NMR spectroscopy, chain extension, and MALDI–MS experiments confirmed the final polymer chains with high fidelity. The use of GVL solvent opens a new route for the easy synthesis of PS through ARGET ATRP with low catalyst usage conditions.
生物基溶剂在活自由基聚合中的应用是近年来的热门话题。本文研究了生物基溶剂γ-戊内酯（GVL）作为苯乙烯（St）ARGET原子转移自由基聚合（ATRP）的绿色介质。我们首先以溴化铜（ii）为催化剂，以三（2-吡啶基甲基）胺为配体，仅以抗坏血酸钠为还原剂，在γ-戊内酯中对苯乙烯进行了聚合。聚合过程实现了中等转化率，但聚合的可控性不佳，得到的聚合物分子量分布较宽（M w/M n > 1.30）。引入碳酸钠后，在催化剂用量极低（5 ppm）的情况下，获得了高产率和低 M w/M n 值的优异结果。1H NMR 光谱、链延伸和 MALDI-MS 实验证实了最终聚合物链的高保真性。GVL 溶剂的使用为在低催化剂用量条件下通过 ARGET ATRP 轻松合成 PS 开辟了一条新途径。
{"title":"ARGET ATRP of styrene with low catalyst usage in bio-based solvent γ-valerolactone","authors":"Qianqian Zhu, Tianchen Song, Jiaxin Zhao, Gang Gao, Yixin Xiang, Jiangang Gao, Xianrong Shen","doi":"10.1515/epoly-2024-0022","DOIUrl":"https://doi.org/10.1515/epoly-2024-0022","url":null,"abstract":"The application of bio-based solvents for living radical polymerization has been a hot topic in recent year. In this article, γ-valerolactone (GVL), a bio-based solvent as green media for ARGET atom transfer radical polymerization (ATRP) of styrene (St) were investigated. We first conducted polymerization of St in γ-valerolactone using copper(<jats:sc>ii</jats:sc>) bromide as the catalyst, tris(2-pyridylmethyl) amine as the ligand, and only sodium ascorbate as reducing agent. The polymerization achieved moderate conversion; however, the controllability of polymerization was not very good, providing a polymer with a broad molecular weight distribution (<jats:italic>M</jats:italic> <jats:sub>w</jats:sub>/<jats:italic>M</jats:italic> <jats:sub>n</jats:sub> <jats:italic>></jats:italic> 1.30). When sodium carbonate is introduced, excellent results were obtained providing high yields and low <jats:italic>M</jats:italic> <jats:sub>w</jats:sub>/<jats:italic>M</jats:italic> <jats:sub>n</jats:sub> values under very low catalyst usage (∼5 ppm). <jats:sup>1</jats:sup>H NMR spectroscopy, chain extension, and MALDI–MS experiments confirmed the final polymer chains with high fidelity. The use of GVL solvent opens a new route for the easy synthesis of PS through ARGET ATRP with low catalyst usage conditions.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"77 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141190427","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}
The use of composite laminates is characterized by problems such as poor inter-layer bonding and susceptibility of material properties to fatigue cracking, which seriously threaten structural safety. Research on fatigue damage characteristics and fatigue life prediction of fiber-reinforced composites can help to solve such problems. Carbon fiber-reinforced epoxy resin matrix composite laminates are taken as the object of this study. By analyzing the fatigue failure process and the fatigue failure micromorphology of the specimen, the primary damage forms and fatigue damage characteristics of its fatigue failure were obtained. The fatigue failure process of fiber-reinforced composites was simulated using finite element analysis software ABAQUS and its UMAT subroutine function. The tensile–tensile fatigue damage characteristics and failure mechanism of fiber-reinforced composites were studied, and the fatigue life of the composites was predicted. The feasibility of this life prediction method was verified by comparing it with experimentally obtained damage processes and fatigue lives. This intuitive and reliable life prediction method has good research potential for predicting the fatigue limit of fiber-reinforced composites.
复合材料层压板在使用过程中存在层间结合力差、材料性能易受疲劳开裂影响等问题，严重威胁结构安全。研究纤维增强复合材料的疲劳损伤特性和疲劳寿命预测有助于解决这些问题。本研究以碳纤维增强环氧树脂基复合材料层压板为对象。通过分析试样的疲劳破坏过程和疲劳破坏微观形貌，获得了其疲劳破坏的主要损伤形式和疲劳损伤特征。利用有限元分析软件 ABAQUS 及其 UMAT 子程序功能模拟了纤维增强复合材料的疲劳破坏过程。研究了纤维增强复合材料的拉伸-拉伸疲劳损伤特征和失效机理，并预测了复合材料的疲劳寿命。通过与实验获得的损伤过程和疲劳寿命进行比较，验证了这种寿命预测方法的可行性。这种直观可靠的寿命预测方法在预测纤维增强复合材料的疲劳极限方面具有良好的研究潜力。
{"title":"Fatigue life prediction method of carbon fiber-reinforced composites","authors":"Jiamei Lai, Yousheng Xia, Zhichao Huang, Bangxiong Liu, Mingzhi Mo, Jiren Yu","doi":"10.1515/epoly-2023-0150","DOIUrl":"https://doi.org/10.1515/epoly-2023-0150","url":null,"abstract":"The use of composite laminates is characterized by problems such as poor inter-layer bonding and susceptibility of material properties to fatigue cracking, which seriously threaten structural safety. Research on fatigue damage characteristics and fatigue life prediction of fiber-reinforced composites can help to solve such problems. Carbon fiber-reinforced epoxy resin matrix composite laminates are taken as the object of this study. By analyzing the fatigue failure process and the fatigue failure micromorphology of the specimen, the primary damage forms and fatigue damage characteristics of its fatigue failure were obtained. The fatigue failure process of fiber-reinforced composites was simulated using finite element analysis software ABAQUS and its UMAT subroutine function. The tensile–tensile fatigue damage characteristics and failure mechanism of fiber-reinforced composites were studied, and the fatigue life of the composites was predicted. The feasibility of this life prediction method was verified by comparing it with experimentally obtained damage processes and fatigue lives. This intuitive and reliable life prediction method has good research potential for predicting the fatigue limit of fiber-reinforced composites.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"89 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141190482","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}
Selamu Temesgen, Mirko Rennert, Tamrat Tesfaye, Lucas Großmann, Ines Kuehnert, Norbert Smolka, Michael Nase
The demand for sustainable textiles has increased research on bio-based biopolymers. Fiber spinning from starch biopolymer and its blends was widely attempted using electro-spinning; however, it is less attempted using melt spinning which is an industrially feasible method. In this study, native tapioca starch is converted into thermoplastic starch (TPS), blended with polylactic acid (PLA), and is attempted for melt spinnability in its neat and blended form TPS/PLA (70/30) with the intention of checking the possibility of melt spinning. The results from characterization of the prepared biopolymers show that thermal analysis of neat TPS does not reveal clear thermal transitions, glass transition (Tg), and melting (Tm), in the second heating curve, rather it influenced crystallization behavior of PLA as seen from differential scanning calorimetry result and degradation temperature (Td) was found to be in the range of 296–352°C from thermogravimetric analysis showing that addition of PLA improved thermal stability of TPS. Morphology analysis with AFM images revealed the presence of granular starch in neat TPS and phase separation in TPS/PLA blends with finer phase distribution in the presence of additives. Fourier transform infrared spectroscopy result shows the interaction between starch, glycerol, and PLA showing the effect of thermoplasticization of starch which brings rupture or weakening of the strong glycosidic bonds in between starch molecules and interaction between TPS and PLA as it can be seen from peak shift and peak intensity. The melt spinning trials show the possibility of melt spinning TPS-based biopolymers into fibers even with higher content of TPS as well as neat TPS giving an insight and motivation for more research engagement. The melt-spun fibers were found to have a diameter in the range of 160.0–117.0 μm. However, additional experiments and investigations are required to improve the mechanical and other properties of the fibers.
{"title":"Thermal, morphological, and structural characterization of starch-based bio-polymers for melt spinnability","authors":"Selamu Temesgen, Mirko Rennert, Tamrat Tesfaye, Lucas Großmann, Ines Kuehnert, Norbert Smolka, Michael Nase","doi":"10.1515/epoly-2024-0025","DOIUrl":"https://doi.org/10.1515/epoly-2024-0025","url":null,"abstract":"The demand for sustainable textiles has increased research on bio-based biopolymers. Fiber spinning from starch biopolymer and its blends was widely attempted using electro-spinning; however, it is less attempted using melt spinning which is an industrially feasible method. In this study, native tapioca starch is converted into thermoplastic starch (TPS), blended with polylactic acid (PLA), and is attempted for melt spinnability in its neat and blended form TPS/PLA (70/30) with the intention of checking the possibility of melt spinning. The results from characterization of the prepared biopolymers show that thermal analysis of neat TPS does not reveal clear thermal transitions, glass transition (<jats:italic>T</jats:italic> <jats:sub>g</jats:sub>), and melting (<jats:italic>T</jats:italic> <jats:sub>m</jats:sub>), in the second heating curve, rather it influenced crystallization behavior of PLA as seen from differential scanning calorimetry result and degradation temperature (<jats:italic>T</jats:italic> <jats:sub>d</jats:sub>) was found to be in the range of 296–352°C from thermogravimetric analysis showing that addition of PLA improved thermal stability of TPS. Morphology analysis with AFM images revealed the presence of granular starch in neat TPS and phase separation in TPS/PLA blends with finer phase distribution in the presence of additives. Fourier transform infrared spectroscopy result shows the interaction between starch, glycerol, and PLA showing the effect of thermoplasticization of starch which brings rupture or weakening of the strong glycosidic bonds in between starch molecules and interaction between TPS and PLA as it can be seen from peak shift and peak intensity. The melt spinning trials show the possibility of melt spinning TPS-based biopolymers into fibers even with higher content of TPS as well as neat TPS giving an insight and motivation for more research engagement. The melt-spun fibers were found to have a diameter in the range of 160.0–117.0 μm. However, additional experiments and investigations are required to improve the mechanical and other properties of the fibers.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"68 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141190450","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}
Jing-Jing Wang, Ying-Guo Zhou, Qian-Qian Zhang, Jun Zou
Graphical abstract Polyglycolide-based polyurethane was synthesized via chain extension reaction. As the hard segment content increases, its thermal stability and mechanical properties are improved; and the weight loss rate in PBS solution is reduced.
{"title":"Synthesis and properties of novel degradable polyglycolide-based polyurethanes","authors":"Jing-Jing Wang, Ying-Guo Zhou, Qian-Qian Zhang, Jun Zou","doi":"10.1515/epoly-2024-0014","DOIUrl":"https://doi.org/10.1515/epoly-2024-0014","url":null,"abstract":"Graphical abstract Polyglycolide-based polyurethane was synthesized via chain extension reaction. As the hard segment content increases, its thermal stability and mechanical properties are improved; and the weight loss rate in PBS solution is reduced.<jats:fig fig-type=\"graphical\"> <jats:graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"graphic/j_epoly-2024-0014_ga_001.jpg\"/> </jats:fig>","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"37 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937286","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}
To investigate the potential applications of bio-based epoxy resins across diverse fields, this study synthesized a bio-based epoxy resin using itaconic acid (EIA) as the precursor material and compared its thermal, mechanical, and electrical properties with those of epoxy acrylate (EA). The findings indicate that the glass transition temperature and the 5% thermal decomposition temperature of the EIA-cured system are higher than those of EA. The breakdown field strength of the EIA-cured system is slightly higher than that of EA (35.58 kV·mm−1), suggesting that EIA exhibits stronger electrical properties compared to EA. Mechanical property tests demonstrate that the tensile strength, elongation at the fracture point, and Shore hardness of the EIA-cured system are superior to those of EA. In conclusion, EIA, serving as a matrix resin, is influenced by cross-linking density and intramolecular ester bonding and exhibits close electrical strength but superior mechanical, thermal, and degradation properties than EA.
{"title":"Preparation of itaconic acid-modified epoxy resins and comparative study on the properties of it and epoxy acrylates","authors":"Qinchen Ye, Qiuli Zhao, Qinghao Yang, Wendong Li, Zhenzhong Hou, Guanjun Zhang","doi":"10.1515/epoly-2023-0182","DOIUrl":"https://doi.org/10.1515/epoly-2023-0182","url":null,"abstract":"To investigate the potential applications of bio-based epoxy resins across diverse fields, this study synthesized a bio-based epoxy resin using itaconic acid (EIA) as the precursor material and compared its thermal, mechanical, and electrical properties with those of epoxy acrylate (EA). The findings indicate that the glass transition temperature and the 5% thermal decomposition temperature of the EIA-cured system are higher than those of EA. The breakdown field strength of the EIA-cured system is slightly higher than that of EA (35.58 kV·mm<jats:sup>−1</jats:sup>), suggesting that EIA exhibits stronger electrical properties compared to EA. Mechanical property tests demonstrate that the tensile strength, elongation at the fracture point, and Shore hardness of the EIA-cured system are superior to those of EA. In conclusion, EIA, serving as a matrix resin, is influenced by cross-linking density and intramolecular ester bonding and exhibits close electrical strength but superior mechanical, thermal, and degradation properties than EA.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"133 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806041","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}
Yulong Ma, Kang Yang, Yi Zhang, Juheng Wang, Shu Zeng, Xiaoxiao Huang
The heterogeneous nucleation process of polypropylene (PP)/high density polyethylene (HDPE)/thermoplastic elastomer (POE) composites was realized through blending modification, and characterization techniques, including scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and dynamic mechanical analysis, were used to analyze the pattern of the impact of modified dicyclohexyl-terephthalamide (TMB-5) on the mechanical properties and thermal stability of the PP/HDPE/POE composites. The results indicated that the modified TMB-5 was advantageous to the improvement of the mechanical properties and thermal stability of the high-temperature (cooking temperature)-resistant PP/HDPE/POE composites. When the amount of added modified TMB-5 was 0.4%, the impact strength and tensile strength of the PP/HDPE/POE composites increased to 36.3 kJ/m2 and 31.7 MPa, respectively, which were, respectively, 99.5% and 8.5% higher than those of the materials prepared when the amount of added modified TMB was 0.1%. The materials had higher storage modulus in room-temperature and high-temperature environments: 2,438.2 MPa (room temperature), 1,103.9 MPa (120°C), and 1,054.8 MPa (140°C). In addition, the capability of the PP/HDPE/POE composites to crystallize was improved continuously, and the crystallinity increased considerably. At the same time, the crystallization and melting temperatures increased, β-crystal formation was induced, and glass transition temperature increased, thus effectively improving the mechanical properties and thermal stability of the high-temperature (cooking temperature)-resistant PP/HDPE/POE composites.
{"title":"Mechanical properties and thermal stability of high-temperature (cooking temperature)-resistant PP/HDPE/POE composites","authors":"Yulong Ma, Kang Yang, Yi Zhang, Juheng Wang, Shu Zeng, Xiaoxiao Huang","doi":"10.1515/epoly-2023-0164","DOIUrl":"https://doi.org/10.1515/epoly-2023-0164","url":null,"abstract":"The heterogeneous nucleation process of polypropylene (PP)/high density polyethylene (HDPE)/thermoplastic elastomer (POE) composites was realized through blending modification, and characterization techniques, including scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and dynamic mechanical analysis, were used to analyze the pattern of the impact of modified dicyclohexyl-terephthalamide (TMB-5) on the mechanical properties and thermal stability of the PP/HDPE/POE composites. The results indicated that the modified TMB-5 was advantageous to the improvement of the mechanical properties and thermal stability of the high-temperature (cooking temperature)-resistant PP/HDPE/POE composites. When the amount of added modified TMB-5 was 0.4%, the impact strength and tensile strength of the PP/HDPE/POE composites increased to 36.3 kJ/m<jats:sup>2</jats:sup> and 31.7 MPa, respectively, which were, respectively, 99.5% and 8.5% higher than those of the materials prepared when the amount of added modified TMB was 0.1%. The materials had higher storage modulus in room-temperature and high-temperature environments: 2,438.2 MPa (room temperature), 1,103.9 MPa (120°C), and 1,054.8 MPa (140°C). In addition, the capability of the PP/HDPE/POE composites to crystallize was improved continuously, and the crystallinity increased considerably. At the same time, the crystallization and melting temperatures increased, β-crystal formation was induced, and glass transition temperature increased, thus effectively improving the mechanical properties and thermal stability of the high-temperature (cooking temperature)-resistant PP/HDPE/POE composites.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"14 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140623557","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}
The structure and transition behavior of crosslinked thermo-responsive poly(2-(2-methoxyethoxy) ethylmethacrylate-co-(ethyleneglycol) methacrylate) (P(MEO2MA-co-EGMA360)) gel film on a flat cellulosic-based substrate were investigated. The regenerated cellulose (RC) film was prepared by spin-coating with trimethylsilyl cellulose (TMSC), followed by etching with hydrochloric acid vapor on a treated silicon wafer, then crosslinked polymer gel film was obtained by spin-coating, drying, and baking with a pre-crosslinked solution containing polymers. Fourier transform infrared spectroscopy, X-ray photoelectron spectrometer, and atomic force microscopy results show that a RC film with a thickness of 25 nm is generated in the upper layer of TMSC film on the silicon wafer. The cross-linking induces closer arrangement and hinders the extension of chain segments, leading to less prominent phase transition behaviors of polymer gel films. By quartz crystal microbalance measurement and 3D microscopes, a phase transition hysteresis is discovered, the hydrated and loose structure of crosslinked polymer gel film switches to dehydrated and compact structure in initial heating process, which subsequently recovers during the following cooling process. However, the degrees of rehydration and flexibility of film could not reach the initial value because of the insufficient transition time and steric hindrance caused by crosslinking.
{"title":"Structure and transition behavior of crosslinked poly(2-(2-methoxyethoxy) ethylmethacrylate-co-(ethyleneglycol) methacrylate) gel film on cellulosic-based flat substrate","authors":"Yangyi Chen, Tong Su, Shihang Zhou, Chendi Xie, Huan Qi, Zaisheng Cai, Liqun Chen","doi":"10.1515/epoly-2023-0147","DOIUrl":"https://doi.org/10.1515/epoly-2023-0147","url":null,"abstract":"The structure and transition behavior of crosslinked thermo-responsive poly(2-(2-methoxyethoxy) ethylmethacrylate-<jats:italic>co</jats:italic>-(ethyleneglycol) methacrylate) (P(MEO<jats:sub>2</jats:sub>MA-<jats:italic>co</jats:italic>-EGMA<jats:sub>360</jats:sub>)) gel film on a flat cellulosic-based substrate were investigated. The regenerated cellulose (RC) film was prepared by spin-coating with trimethylsilyl cellulose (TMSC), followed by etching with hydrochloric acid vapor on a treated silicon wafer, then crosslinked polymer gel film was obtained by spin-coating, drying, and baking with a pre-crosslinked solution containing polymers. Fourier transform infrared spectroscopy, X-ray photoelectron spectrometer, and atomic force microscopy results show that a RC film with a thickness of 25 nm is generated in the upper layer of TMSC film on the silicon wafer. The cross-linking induces closer arrangement and hinders the extension of chain segments, leading to less prominent phase transition behaviors of polymer gel films. By quartz crystal microbalance measurement and 3D microscopes, a phase transition hysteresis is discovered, the hydrated and loose structure of crosslinked polymer gel film switches to dehydrated and compact structure in initial heating process, which subsequently recovers during the following cooling process. However, the degrees of rehydration and flexibility of film could not reach the initial value because of the insufficient transition time and steric hindrance caused by crosslinking.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"71 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140608468","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}
With the help of bolted joints to assemble a complex structure, carbon fiber reinforced polymer composite (CFRP) is widely used in various fields. However, stress concentration around holes at the bolted joints leads to a decrease in bearing capacity. Composites often result in mechanical degradation subjected to a complex hydrothermal environment. Therefore, to study the tensile behavior of CFRP bolted joints subjected to hydrothermal aging, the tensile tests are conducted carefully. The influence of aging time and temperature on tensile strength is investigated based on the response history, strain contour, and failure morphology. The failure mechanism is revealed via digital image correlation technology. Finally, the experimental results demonstrate that the bearing capacity of the structure in hydrothermal aging decreases significantly. Compared with the unaged specimens, the peak force of the specimens aged for 6 weeks at 25°C and 65°C is reduced by 22.79% and 35.63%, respectively. Under both the unaged and aged, the same bearing failure is found in the tensile tests of CFRP single-bolt single-lap joints.
{"title":"Experimental investigation on tensile behavior of CFRP bolted joints subjected to hydrothermal aging","authors":"Hui Chen, Mingjie Li, Zhao Shen, Yitao Zhang, Youhua Zhu, Ye Wu","doi":"10.1515/epoly-2023-0183","DOIUrl":"https://doi.org/10.1515/epoly-2023-0183","url":null,"abstract":"With the help of bolted joints to assemble a complex structure, carbon fiber reinforced polymer composite (CFRP) is widely used in various fields. However, stress concentration around holes at the bolted joints leads to a decrease in bearing capacity. Composites often result in mechanical degradation subjected to a complex hydrothermal environment. Therefore, to study the tensile behavior of CFRP bolted joints subjected to hydrothermal aging, the tensile tests are conducted carefully. The influence of aging time and temperature on tensile strength is investigated based on the response history, strain contour, and failure morphology. The failure mechanism is revealed via digital image correlation technology. Finally, the experimental results demonstrate that the bearing capacity of the structure in hydrothermal aging decreases significantly. Compared with the unaged specimens, the peak force of the specimens aged for 6 weeks at 25°C and 65°C is reduced by 22.79% and 35.63%, respectively. Under both the unaged and aged, the same bearing failure is found in the tensile tests of CFRP single-bolt single-lap joints.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"195 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140565689","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}
Mohammad Zahirul Islam Mollah, Md. Sumon Miah, Md. Washim Akram, Sayed Hasan Mahmud, Mohammad Rashed Iqbal Faruque, Kholoud Saad Al-mugren
Reinforced composite made of polypropylene combining banana and betel nut husk fiber (BBF) was treated with 10% NaOH (w/w). The fiber percentages of 40%, 50%, and 60% were used using the compression molding process. Properties such as tensile, bending, impact, thermogravimetric analysis (TGA), and water absorption were assessed as composite reinforcements. The composites with 50% BBF reinforcement performed better than composites with different fiber compositions. While 40% BBF-reinforced showed superior results in tensile, bending, and water absorption tests, the impact and TGA analyses provided comparatively lower results. The tensile strength (36 MPa), bending strength (78 MPa), energy absorption (2.4 Nm), thermal resistance (300–583°), and the maximum level of characteristics were attained. This work demonstrated the feasibility of repurposing waste banana stems and betel nut husks for interior decoration, furniture, and automobile bodies in fiber-reinforced hybrid composites, replacing expensive and environmentally hazardous artificial materials due to their mechanical capabilities.
{"title":"Thermoplastic-polymer matrix composite of banana/betel nut husk fiber reinforcement: Physico-mechanical properties evaluation","authors":"Mohammad Zahirul Islam Mollah, Md. Sumon Miah, Md. Washim Akram, Sayed Hasan Mahmud, Mohammad Rashed Iqbal Faruque, Kholoud Saad Al-mugren","doi":"10.1515/epoly-2023-0158","DOIUrl":"https://doi.org/10.1515/epoly-2023-0158","url":null,"abstract":"Reinforced composite made of polypropylene combining banana and betel nut husk fiber (BBF) was treated with 10% NaOH (w/w). The fiber percentages of 40%, 50%, and 60% were used using the compression molding process. Properties such as tensile, bending, impact, thermogravimetric analysis (TGA), and water absorption were assessed as composite reinforcements. The composites with 50% BBF reinforcement performed better than composites with different fiber compositions. While 40% BBF-reinforced showed superior results in tensile, bending, and water absorption tests, the impact and TGA analyses provided comparatively lower results. The tensile strength (36 MPa), bending strength (78 MPa), energy absorption (2.4 Nm), thermal resistance (300–583°), and the maximum level of characteristics were attained. This work demonstrated the feasibility of repurposing waste banana stems and betel nut husks for interior decoration, furniture, and automobile bodies in fiber-reinforced hybrid composites, replacing expensive and environmentally hazardous artificial materials due to their mechanical capabilities.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"58 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140565684","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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