Two-dimensional models of die-melt and die-gas-melt were created using Polyflow software. The radial and axial directions flow rate, shear rate, pressure, and first normal stress of the specimen were numerically simulated under conventional extrusion and gas-assisted extrusion while taking into consideration the heat transfer on the free surface of the specimen. The crystallinity was determined by combining the simulation data with the crystallization kinetics equation. The computation results are then examined using Origin software. The findings demonstrate that the use of gas-assisted extrusion technology can cause the Vx to decrease or even turn negative by reducing the friction between the melting edge and the die wall. Additionally, it makes Vy, pressure, shear rate, temperature, first normal stress, and crystallinity increasingly steady and aids in reducing or avoiding the Barus effect. The crystallization phenomena can be measured by using the crystallization kinetics equation. The study of extruded parts at the microscopic level will benefit from this application.
{"title":"Comparative analysis of flow factors and crystallinity in conventional extrusion and gas-assisted extrusion","authors":"Xuemei Huang, Hesheng Liu, Xingyuan Huang, Yibin Huang, Zhong Yu","doi":"10.1515/epoly-2023-0076","DOIUrl":"https://doi.org/10.1515/epoly-2023-0076","url":null,"abstract":"Two-dimensional models of die-melt and die-gas-melt were created using Polyflow software. The radial and axial directions flow rate, shear rate, pressure, and first normal stress of the specimen were numerically simulated under conventional extrusion and gas-assisted extrusion while taking into consideration the heat transfer on the free surface of the specimen. The crystallinity was determined by combining the simulation data with the crystallization kinetics equation. The computation results are then examined using Origin software. The findings demonstrate that the use of gas-assisted extrusion technology can cause the <jats:italic>V<jats:sub>x</jats:sub> </jats:italic> to decrease or even turn negative by reducing the friction between the melting edge and the die wall. Additionally, it makes <jats:italic>V<jats:sub>y</jats:sub> </jats:italic>, pressure, shear rate, temperature, first normal stress, and crystallinity increasingly steady and aids in reducing or avoiding the Barus effect. The crystallization phenomena can be measured by using the crystallization kinetics equation. The study of extruded parts at the microscopic level will benefit from this application.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"37 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202306","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}
A scalable approach for manufacturing highly stretchable thermochromic wrapped yarns has been reported previously. Herein, the effects of twist-related technological parameters, namely, wrapping density and outer-inner twist ratio are investigated and have been optimized by technique for order preference by similarity to ideal solution (TOPSIS). The results indicate that the preparatory twist-related parameters have a remarkable effect on the spiral geometrical configuration of yarn constituents, and thus in turn influencing the final tensile and elastic properties of wrapped yarns. The wrapping density of 800 T·m−1 and outer-inner twist ratio of 1.25 were considered as the optimal alternative using TOPSIS. Moreover, a negative relation between voltage and color-changing time of yarn spun with optimal parameters was established. It was also found that the color of yarn above elevated triggered voltages always switched from purple to pink but followed different color-changing paths. More importantly, thermochromic response of yarn is insensitive to the applied strain.
{"title":"Twist-related parametric optimization of Joule heating-triggered highly stretchable thermochromic wrapped yarns using technique for order preference by similarity to ideal solution","authors":"Yong Wang, Zihan Yuan, Mingkun Qi, Lizheng Zhang, Mingwei Li, Wei Wang, Changlong Li","doi":"10.1515/epoly-2024-0009","DOIUrl":"https://doi.org/10.1515/epoly-2024-0009","url":null,"abstract":"A scalable approach for manufacturing highly stretchable thermochromic wrapped yarns has been reported previously. Herein, the effects of twist-related technological parameters, namely, wrapping density and outer-inner twist ratio are investigated and have been optimized by technique for order preference by similarity to ideal solution (TOPSIS). The results indicate that the preparatory twist-related parameters have a remarkable effect on the spiral geometrical configuration of yarn constituents, and thus in turn influencing the final tensile and elastic properties of wrapped yarns. The wrapping density of 800 T·m<jats:sup>−1</jats:sup> and outer-inner twist ratio of 1.25 were considered as the optimal alternative using TOPSIS. Moreover, a negative relation between voltage and color-changing time of yarn spun with optimal parameters was established. It was also found that the color of yarn above elevated triggered voltages always switched from purple to pink but followed different color-changing paths. More importantly, thermochromic response of yarn is insensitive to the applied strain.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"20 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202397","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 address the undesirable reactions associated with matrine (MAT) injection in clinical settings, a high-loading drug delivery system (DDS) based on pH-sensitive molecularly imprinted polymer (MAT@MIPs) was prepared for the first time. The imprinted materials containing recognition sites for the matrine were formed by using carboxyl-functionalized multiwalled carbon nanotubes as a supportive matrix and dopamine as a cross-linker due to its exceptional biocompatibility. Subsequently, the optimal reaction conditions and adsorption performance of MAT@MIPs were systematically investigated. The obtained polymers were characterized and evaluated by Fourier transform infrared spectrometry, scanning electron microscopy, elemental analysis, and thermogravimetric analysis. Results indicated that the MIPs demonstrated a favorable imprinting factor (2.36) and a high binding capacity (21.48 mg·g−1) for matrine. In vitro studies, we performed cell counting kit-8 assays in HepG2 cells, then the drug delivery capabilities of MAT-loaded MIPs were validated through light microscopy analyses, and the matrine content in culture medium was quantified using ultra high-performance liquid chromatography-mass spectrum synchronously. The facile fabrication of MAT@MIPs presents a viable solution for designing high-loading and pH-responsive DDS, which can offer a novel administration approach for drugs requiring injection in clinical applications.
{"title":"Synthesis, characterization and evaluation of a pH-responsive molecular imprinted polymer for Matrine as an intelligent drug delivery system","authors":"Yanhui Ge, Liuyang Ding, Yubo Liu, Xiong Li","doi":"10.1515/epoly-2023-0184","DOIUrl":"https://doi.org/10.1515/epoly-2023-0184","url":null,"abstract":"To address the undesirable reactions associated with matrine (MAT) injection in clinical settings, a high-loading drug delivery system (DDS) based on pH-sensitive molecularly imprinted polymer (MAT@MIPs) was prepared for the first time. The imprinted materials containing recognition sites for the matrine were formed by using carboxyl-functionalized multiwalled carbon nanotubes as a supportive matrix and dopamine as a cross-linker due to its exceptional biocompatibility. Subsequently, the optimal reaction conditions and adsorption performance of MAT@MIPs were systematically investigated. The obtained polymers were characterized and evaluated by Fourier transform infrared spectrometry, scanning electron microscopy, elemental analysis, and thermogravimetric analysis. Results indicated that the MIPs demonstrated a favorable imprinting factor (2.36) and a high binding capacity (21.48 mg·g<jats:sup>−1</jats:sup>) for matrine. <jats:italic>In vitro</jats:italic> studies, we performed cell counting kit-8 assays in HepG2 cells, then the drug delivery capabilities of MAT-loaded MIPs were validated through light microscopy analyses, and the matrine content in culture medium was quantified using ultra high-performance liquid chromatography-mass spectrum synchronously. The facile fabrication of MAT@MIPs presents a viable solution for designing high-loading and pH-responsive DDS, which can offer a novel administration approach for drugs requiring injection in clinical applications.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"20 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202301","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}
Yilin Tu, Xu Li, Hongyuan Huang, Chen Chen, Gang Liu, Youping Liu, Ye Wu
To study the impact response and compression-after-impact (CAI) behavior of perforated sandwich panels comprised of foam core and glass fiber-reinforced epoxy hybrid facesheets, the hole diameter of specimens is changed in the fabrication via vacuum-assisted resin infusion. Furthermore, low-velocity-impact tests with various impact distances between the impact point and hole are carried out. With the help of the digital image correlation technique, CAI testing is conducted, and the strain evolution of specimens is monitored carefully. The mechanical response history, damage morphology, and compressive process are discussed in detail. The results show that the impact and CAI performance of specimens are weakened because of open holes. Compared with the non-perforated specimen, the maximum force of the specimen with a 6-mm hole and the 5-mm impact distance decreases by 41.21%, and its maximum displacement increases by 38.60%. During the CAI process, in comparison with the impact damage, more significant stress concentration and buckling around the hole are found.
为了研究由泡沫夹芯和玻璃纤维增强环氧混合面层组成的穿孔夹芯板的冲击响应和冲击后压缩（CAI）行为，在制作过程中通过真空辅助树脂灌注改变了试样的孔径。此外，还进行了冲击点与孔之间不同冲击距离的低速冲击试验。在数字图像相关技术的帮助下，进行了 CAI 试验，并仔细监测了试样的应变演变。详细讨论了机械响应历史、损伤形态和压缩过程。结果表明，试样的冲击和 CAI 性能因开孔而减弱。与无孔试样相比，孔径为 6 毫米、冲击距离为 5 毫米的试样的最大力下降了 41.21%，最大位移增加了 38.60%。在 CAI 过程中，与冲击破坏相比，孔周围的应力集中和屈曲更为明显。
{"title":"Experimental evaluation on compression-after-impact behavior of perforated sandwich panel comprised of foam core and glass fiber reinforced epoxy hybrid facesheets","authors":"Yilin Tu, Xu Li, Hongyuan Huang, Chen Chen, Gang Liu, Youping Liu, Ye Wu","doi":"10.1515/epoly-2024-0021","DOIUrl":"https://doi.org/10.1515/epoly-2024-0021","url":null,"abstract":"To study the impact response and compression-after-impact (CAI) behavior of perforated sandwich panels comprised of foam core and glass fiber-reinforced epoxy hybrid facesheets, the hole diameter of specimens is changed in the fabrication via vacuum-assisted resin infusion. Furthermore, low-velocity-impact tests with various impact distances between the impact point and hole are carried out. With the help of the digital image correlation technique, CAI testing is conducted, and the strain evolution of specimens is monitored carefully. The mechanical response history, damage morphology, and compressive process are discussed in detail. The results show that the impact and CAI performance of specimens are weakened because of open holes. Compared with the non-perforated specimen, the maximum force of the specimen with a 6-mm hole and the 5-mm impact distance decreases by 41.21%, and its maximum displacement increases by 38.60%. During the CAI process, in comparison with the impact damage, more significant stress concentration and buckling around the hole are found.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"31 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140167970","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 pursuit of high-performance polyolefin materials has been an objective for chemists. Recently, the development of multinuclear catalysts has significantly enabled the preparation of high-performance polyolefin materials. In this review, we mainly focus on the cooperative effects of multinuclear early transition metal catalysts and provide a comprehensive summary of the research progress in binuclear and multinuclear early transition metal catalysts over the past decade. Compared with the catalytic performance and polymer structure of these catalysts with mononuclear catalysts, we have found that various factors, such as steric hindrance effect, electronic effect, heteroatom effect, hydrogen bonding interaction, the distance between metal centers in multinuclear metal catalysts, and the use of additives, have distinctive and significant impacts on catalyst performance. These effects give rise to notable cooperative effects. This review offers crucial insights and serves as a valuable reference for shaping the future development directions of binuclear and multinuclear early transition metal catalysts.
{"title":"Recent advancements in multinuclear early transition metal catalysts for olefin polymerization through cooperative effects","authors":"Qiang Yue, Rong Gao, Zhihui Song, Jingjing Lai, Randi Zhang, Ying Wang, Qingqiang Gou","doi":"10.1515/epoly-2023-0195","DOIUrl":"https://doi.org/10.1515/epoly-2023-0195","url":null,"abstract":"The pursuit of high-performance polyolefin materials has been an objective for chemists. Recently, the development of multinuclear catalysts has significantly enabled the preparation of high-performance polyolefin materials. In this review, we mainly focus on the cooperative effects of multinuclear early transition metal catalysts and provide a comprehensive summary of the research progress in binuclear and multinuclear early transition metal catalysts over the past decade. Compared with the catalytic performance and polymer structure of these catalysts with mononuclear catalysts, we have found that various factors, such as steric hindrance effect, electronic effect, heteroatom effect, hydrogen bonding interaction, the distance between metal centers in multinuclear metal catalysts, and the use of additives, have distinctive and significant impacts on catalyst performance. These effects give rise to notable cooperative effects. This review offers crucial insights and serves as a valuable reference for shaping the future development directions of binuclear and multinuclear early transition metal catalysts.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"40 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140167972","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 dripping behaviour of polymers is often observed experimentally through the UL94 flammability standard test. In this work, polymeric dripping under fire is investigated numerically using particle finite element method. A parametric analysis was carried out to observe the influence of a single property on overall dripping behaviour via a UL94 vertical test model. Surrogates and property ranges were defined for variation of the following parameters: glass transition temperature (Tg), melting temperature (Tm), decomposition temperature (Td), density (ρ), specific heat capacity (Cp), apparent effective heat of combustion of the volatiles, char yield (µ), thermal conductivity (k), and viscosity (η). Polyamide, poly(ether ether ketone), poly(methyl methacrylate), and polysulfone were used as benchmarks. Simulated results showed that specific heat capacity, thermal conductivity, and char yield allied with viscosity were the properties that most influenced dripping behaviour (starting time and occurrence).
{"title":"The effects of property variation on the dripping behaviour of polymers during UL94 test simulated by particle finite element method","authors":"Analice Turski Silva Diniz, Bernhard Schartel","doi":"10.1515/epoly-2023-0194","DOIUrl":"https://doi.org/10.1515/epoly-2023-0194","url":null,"abstract":"The dripping behaviour of polymers is often observed experimentally through the UL94 flammability standard test. In this work, polymeric dripping under fire is investigated numerically using particle finite element method. A parametric analysis was carried out to observe the influence of a single property on overall dripping behaviour via a UL94 vertical test model. Surrogates and property ranges were defined for variation of the following parameters: glass transition temperature (<jats:italic>T</jats:italic> <jats:sub>g</jats:sub>), melting temperature (<jats:italic>T</jats:italic> <jats:sub>m</jats:sub>), decomposition temperature (<jats:italic>T</jats:italic> <jats:sub>d</jats:sub>), density (<jats:italic>ρ</jats:italic>), specific heat capacity (Cp), apparent effective heat of combustion of the volatiles, char yield (<jats:italic>µ</jats:italic>), thermal conductivity (<jats:italic>k</jats:italic>), and viscosity (<jats:italic>η</jats:italic>). Polyamide, poly(ether ether ketone), poly(methyl methacrylate), and polysulfone were used as benchmarks. Simulated results showed that specific heat capacity, thermal conductivity, and char yield allied with viscosity were the properties that most influenced dripping behaviour (starting time and occurrence).","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"2014 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140167971","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}
Capacitive deionization electrode prepared by coating was commonly investigated, with polymer solution as binder and active particles as adsorbent. In the coating process, microstructure constituted by the two components was damaged by shear, then rebuilt when shear was removed. The microstructure strongly influenced the surface structure of the coated electrodes, further to performance and cycle life. The discussion of the interaction between the components in the coating process facilitates the identification of structural mechanisms. Rheology bridged the flow regimes in macroscale and interaction in microscale, through which the interaction between the polymer and particles can be investigated in a macroscopic phenomenon. In this study, hydrophilic polymer, poly(vinyl alcohol) (PVA), and poly(ethylene oxide) (PEO) were used as binders to prepare the suspension for coating. The influence of polymer molecular structure to interaction and microstructure was investigated by rheology. Results showed that the flexibility of polymer determined the adsorption morphology, leading to different flocculation structures. For rigid PVA, a 3d-crosslinked network was formed, giving a tough coating. While for flexible PEO, encapsulation structure was formed, leading to a brittle coating. A model based on bridging flocculation was evaluated to describe the formation and destruction of the flocculation structure. And a rheological method for binder selection and coating operation was proposed.
以聚合物溶液为粘合剂，活性颗粒为吸附剂，通过涂层制备电容式去离子电极的研究很普遍。在涂覆过程中，两种成分构成的微观结构受到剪切力的破坏，然后在去除剪切力后重建。微观结构对涂层电极的表面结构有很大影响，并进一步影响电极的性能和循环寿命。对涂层过程中各成分之间相互作用的讨论有助于确定结构机制。流变学为宏观尺度的流动和微观尺度的相互作用架起了桥梁，通过流变学可以在宏观现象中研究聚合物和颗粒之间的相互作用。本研究使用亲水性聚合物聚乙烯醇（PVA）和聚环氧乙烷（PEO）作为粘合剂制备涂层悬浮液。流变学研究了聚合物分子结构对相互作用和微观结构的影响。结果表明，聚合物的柔韧性决定了吸附形态，从而导致不同的絮凝结构。对于刚性 PVA，形成了 3d 交联网络，形成了坚韧的涂层。而对于柔性 PEO，则形成了封装结构，导致涂层变脆。评估了一个基于架桥絮凝的模型，以描述絮凝结构的形成和破坏。此外，还提出了一种用于选择粘合剂和涂层操作的流变学方法。
{"title":"Rheological behavior of particle-filled polymer suspensions and its influence on surface structure of the coated electrodes","authors":"Hao Ming, Yinyan Guan, Cong Geng, Yingjun Gao, Jing Meng, Jiyan Liang","doi":"10.1515/epoly-2023-0133","DOIUrl":"https://doi.org/10.1515/epoly-2023-0133","url":null,"abstract":"Capacitive deionization electrode prepared by coating was commonly investigated, with polymer solution as binder and active particles as adsorbent. In the coating process, microstructure constituted by the two components was damaged by shear, then rebuilt when shear was removed. The microstructure strongly influenced the surface structure of the coated electrodes, further to performance and cycle life. The discussion of the interaction between the components in the coating process facilitates the identification of structural mechanisms. Rheology bridged the flow regimes in macroscale and interaction in microscale, through which the interaction between the polymer and particles can be investigated in a macroscopic phenomenon. In this study, hydrophilic polymer, poly(vinyl alcohol) (PVA), and poly(ethylene oxide) (PEO) were used as binders to prepare the suspension for coating. The influence of polymer molecular structure to interaction and microstructure was investigated by rheology. Results showed that the flexibility of polymer determined the adsorption morphology, leading to different flocculation structures. For rigid PVA, a 3d-crosslinked network was formed, giving a tough coating. While for flexible PEO, encapsulation structure was formed, leading to a brittle coating. A model based on bridging flocculation was evaluated to describe the formation and destruction of the flocculation structure. And a rheological method for binder selection and coating operation was proposed.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"34 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140168088","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}
Xiaofeng Yu, Jiawei Xie, Bixing Yan, Renyuan Song, Kun Chen, Hegang Yan
Porous molecularly imprinted polymer (MIP) microspheres were synthesized via iniferter-suspension polymerization method, employing lenacil (LA) as the template molecule and methacrylic acid (MAA) as the functional monomer. The host–guest complexes formed using LA and MAA were characterized by hydrogen nuclear magnetic resonance and ultraviolet–visible absorption spectroscopy. The obtained results showed that the interaction between LA and MAA mainly relied on hydrogen bonding. The surface morphologies and chemical structures of the MIPs were characterized by scanning electron microscopy. MIPs were spherical in shape with a relatively regular sphericity, rough surface structure, and numerous small holes, which significantly reduced the mass transfer resistance of the template molecules and exhibited excellent recognition performance for template molecules. In addition, soil samples were pretreated with solid-phase extraction columns molecularly imprinted with LA, and analyzed by high-performance liquid chromatography. The recoveries of LA, bromacil, and terbacil were up to 89.65%, 53.17%, and 44.63%, respectively. The developed method showed a minimum detection limit of 10–50 µg·mL−1. In view of the continuous increase of public requirements for pesticide residue detection, a versatile pretreatment method was developed that is green, rapid, simple, and can be miniaturized.
以来那西尔（LA）为模板分子，甲基丙烯酸（MAA）为功能单体，通过增殖悬浮聚合法合成了多孔分子印迹聚合物（MIP）微球。利用氢核磁共振和紫外可见吸收光谱对以 LA 和 MAA 形成的主客复合物进行了表征。结果表明，LA 和 MAA 之间的相互作用主要依靠氢键。扫描电子显微镜对 MIPs 的表面形态和化学结构进行了表征。MIPs呈球形，球度相对规则，表面结构粗糙，并有许多小孔，这大大降低了模板分子的传质阻力，对模板分子具有良好的识别性能。此外，土壤样品经与 LA 分子印迹的固相萃取柱预处理后，采用高效液相色谱法进行分析。LA、溴嘧啶和特巴嘧啶的回收率分别高达89.65%、53.17%和44.63%。该方法的最低检测限为 10-50 µg-mL-1。鉴于公众对农药残留检测要求的不断提高，本研究建立了一种绿色、快速、简便、可微型化的多功能前处理方法。
{"title":"Determination of pesticide residue in soil samples by molecularly imprinted solid-phase extraction method","authors":"Xiaofeng Yu, Jiawei Xie, Bixing Yan, Renyuan Song, Kun Chen, Hegang Yan","doi":"10.1515/epoly-2023-0174","DOIUrl":"https://doi.org/10.1515/epoly-2023-0174","url":null,"abstract":"Porous molecularly imprinted polymer (MIP) microspheres were synthesized via iniferter-suspension polymerization method, employing lenacil (LA) as the template molecule and methacrylic acid (MAA) as the functional monomer. The host–guest complexes formed using LA and MAA were characterized by hydrogen nuclear magnetic resonance and ultraviolet–visible absorption spectroscopy. The obtained results showed that the interaction between LA and MAA mainly relied on hydrogen bonding. The surface morphologies and chemical structures of the MIPs were characterized by scanning electron microscopy. MIPs were spherical in shape with a relatively regular sphericity, rough surface structure, and numerous small holes, which significantly reduced the mass transfer resistance of the template molecules and exhibited excellent recognition performance for template molecules. In addition, soil samples were pretreated with solid-phase extraction columns molecularly imprinted with LA, and analyzed by high-performance liquid chromatography. The recoveries of LA, bromacil, and terbacil were up to 89.65%, 53.17%, and 44.63%, respectively. The developed method showed a minimum detection limit of 10–50 µg·mL<jats:sup>−1</jats:sup>. In view of the continuous increase of public requirements for pesticide residue detection, a versatile pretreatment method was developed that is green, rapid, simple, and can be miniaturized.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"16 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140149745","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}
For eliminating the die swell phenomenon in 3D printing of GF/PP, a hot air assisted 3D printing method is proposed and its mechanism is studied. A two-phase flow model consisting of compressible gas and in-compressible melt is established, and the process of polymer filament extrusion is simulated. A series of experiments are conducted to compare the differences between traditional printing and gas-assisted printing in terms of extruded filament, temperature, and morphology. The simulation and experiment results show that the addition of gas effectively mitigates the melt die swell, and increases the extrusion filament temperature to more than 70°C. The extrusion pressure is reduced about two orders of magnitude, and the first normal stress is decreased from 400,000 to 20,000 Pa. The surface morphology of printed product is smoother and more refined. This study provides valuable information for understanding the principles of gas-assisted printing and demonstrates its potential for improving printing quality and efficiency.
为消除 GF/PP 三维打印中的模具膨胀现象，提出了一种热风辅助三维打印方法，并对其机理进行了研究。建立了由可压缩气体和不可压缩熔体组成的两相流动模型，并模拟了聚合物长丝挤出过程。通过一系列实验，比较了传统印刷和气体辅助印刷在挤出丝、温度和形态方面的差异。模拟和实验结果表明，添加气体可有效缓解熔模膨胀，并将挤出丝的温度提高到 70°C 以上。挤出压力降低了约两个数量级，第一法向应力从 400,000 Pa 降至 20,000 Pa。印刷产品的表面形态更加光滑细腻。这项研究为了解气体辅助印刷的原理提供了有价值的信息，并证明了其在提高印刷质量和效率方面的潜力。
{"title":"The die swell eliminating mechanism of hot air assisted 3D printing of GF/PP and its influence on the product performance","authors":"Ru Yang, Jianhua Xiao, YingLan Liu, ShiKang Xu","doi":"10.1515/epoly-2024-0008","DOIUrl":"https://doi.org/10.1515/epoly-2024-0008","url":null,"abstract":"For eliminating the die swell phenomenon in 3D printing of GF/PP, a hot air assisted 3D printing method is proposed and its mechanism is studied. A two-phase flow model consisting of compressible gas and in-compressible melt is established, and the process of polymer filament extrusion is simulated. A series of experiments are conducted to compare the differences between traditional printing and gas-assisted printing in terms of extruded filament, temperature, and morphology. The simulation and experiment results show that the addition of gas effectively mitigates the melt die swell, and increases the extrusion filament temperature to more than 70°C. The extrusion pressure is reduced about two orders of magnitude, and the first normal stress is decreased from 400,000 to 20,000 Pa. The surface morphology of printed product is smoother and more refined. This study provides valuable information for understanding the principles of gas-assisted printing and demonstrates its potential for improving printing quality and efficiency.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"102 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140156796","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}
In this study, we realized a highly luminescent polyester fiber using a special spinneret orifice comprised of eight C-shaped pores and specific process parameters. A moderate amount of reversible photochromism materials was added along with the specific color masterbatch of suitable materials. With its high light transmittance and reflectance, the fabric has high glossiness and excellent transparency and exhibits dazzling color effects with changes in ambient light intensity. The raw materials used are polyethylene terephthalate (PET) chips with a low melting point of 110–150°C, 0.3–0.5% (active ingredient 30%) masterbatch, and 40–50% (active ingredient 50%) reversible photochromism masterbatch. The following process parameters were also chosen: for the PET chips, the drying temperature was 80–90°C, the drying time was 12–14 h, the masterbatch drying temperature was 70–80°C, the drying time was 8–10 h, the spinning temperature was 220–230°C, the cooling air temperature was 15–17°C, the cooling air speed was 0.45–0.50 m·min−1, the first hot roller temperature was 75–80°C, and the secondary hot roller had the heater turned off.
{"title":"Preparation and application of profiled luminescent polyester fiber with reversible photochromism materials","authors":"Yaoding Tao, Shouyun Zhang, Mei Xu, Qiang Shu, Shang Gao, Yanan Liu, Peisong Wang, Ruijia Cheng","doi":"10.1515/epoly-2023-0121","DOIUrl":"https://doi.org/10.1515/epoly-2023-0121","url":null,"abstract":"In this study, we realized a highly luminescent polyester fiber using a special spinneret orifice comprised of eight C-shaped pores and specific process parameters. A moderate amount of reversible photochromism materials was added along with the specific color masterbatch of suitable materials. With its high light transmittance and reflectance, the fabric has high glossiness and excellent transparency and exhibits dazzling color effects with changes in ambient light intensity. The raw materials used are polyethylene terephthalate (PET) chips with a low melting point of 110–150°C, 0.3–0.5% (active ingredient 30%) masterbatch, and 40–50% (active ingredient 50%) reversible photochromism masterbatch. The following process parameters were also chosen: for the PET chips, the drying temperature was 80–90°C, the drying time was 12–14 h, the masterbatch drying temperature was 70–80°C, the drying time was 8–10 h, the spinning temperature was 220–230°C, the cooling air temperature was 15–17°C, the cooling air speed was 0.45–0.50 m·min<jats:sup>−1</jats:sup>, the first hot roller temperature was 75–80°C, and the secondary hot roller had the heater turned off.","PeriodicalId":11806,"journal":{"name":"e-Polymers","volume":"44 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140149519","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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