Elder Pacheco da Cruz, Felipe Nardo dos Santos, Jaqueline Ferreira de Souza, Estefania Júlia Dierings de Souza, Laura Martins Fonseca, André Ricardo Fajardo, Elessandra Rosa da Zavareze, Alvaro Renato Guerra Dias
Polymer concentration and aging time of polymeric solutions are crucial factors that can influence their viscosity, playing an essential role in the fabrication of electrospun nanofibers. Based on this, herein we evaluated the impact of aging time (24 and 48 h) and pea starch concentration (10%, 20%, and 30%, wt/vol) on the polymeric solutions to produce electrospun nanofibers. Solutions were evaluated by rheology, electrical conductivity, and degree of substitution. The nanofibers were analyzed by morphology, size distribution, chemical nature, and thermal properties. The degree of substitution of starches varied from 1.17 to 1.56. Overall, electrical conductivity decreased with increasing starch concentration and aging time of the polymeric solutions. The use of 10% starch displayed a transition from capsules to fibers, while 20% and 30% starch were able to manufacture homogenous, cylindrical, and random nanofibers with diameters varying from 89 to 373 nm. A significant impact of viscosity was not observed; on the other hand, aging time increased the average diameter of nanofibers. Besides, the fabricated nanofibers showed a lower decomposition temperature than raw starch. The fabricated nanofibers have great potential as wall materials for the encapsulation of different compounds and applications in the biomedical and food sectors.
{"title":"Impact of concentration and aging time of pea starch‐based polymeric solutions on the fabrication of electrospun nanofibers","authors":"Elder Pacheco da Cruz, Felipe Nardo dos Santos, Jaqueline Ferreira de Souza, Estefania Júlia Dierings de Souza, Laura Martins Fonseca, André Ricardo Fajardo, Elessandra Rosa da Zavareze, Alvaro Renato Guerra Dias","doi":"10.1002/pat.6479","DOIUrl":"https://doi.org/10.1002/pat.6479","url":null,"abstract":"Polymer concentration and aging time of polymeric solutions are crucial factors that can influence their viscosity, playing an essential role in the fabrication of electrospun nanofibers. Based on this, herein we evaluated the impact of aging time (24 and 48 h) and pea starch concentration (10%, 20%, and 30%, wt/vol) on the polymeric solutions to produce electrospun nanofibers. Solutions were evaluated by rheology, electrical conductivity, and degree of substitution. The nanofibers were analyzed by morphology, size distribution, chemical nature, and thermal properties. The degree of substitution of starches varied from 1.17 to 1.56. Overall, electrical conductivity decreased with increasing starch concentration and aging time of the polymeric solutions. The use of 10% starch displayed a transition from capsules to fibers, while 20% and 30% starch were able to manufacture homogenous, cylindrical, and random nanofibers with diameters varying from 89 to 373 nm. A significant impact of viscosity was not observed; on the other hand, aging time increased the average diameter of nanofibers. Besides, the fabricated nanofibers showed a lower decomposition temperature than raw starch. The fabricated nanofibers have great potential as wall materials for the encapsulation of different compounds and applications in the biomedical and food sectors.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"80 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electric field plays a pivotal role in electrospinning to produce the desired micro and nanofibers, hence, a tricipital‐needle spinneret was developed to improve electric field distribution and productivity in this work. The effects of electric field distribution induced by spinneret configuration on jet motion, fiber morphology, and properties of electrospun TPU fibrous membrane at different applied voltages were investigated by simulation and experiment. The simulation results show that the designed tricipital‐needle spinneret weakens the electric field near the needle tip and strengthens the electric field in the whipping region in comparison to the single‐needle spinneret, exhibiting a relatively uniform electric field distribution. The experimental results demonstrate that the fiber diameter prepared by the tricipital‐needle spinneret at the corresponding voltage is smaller than that of the single‐needle spinneret due to the improved electric field distribution. Moreover, the fibrous membrane prepared by the tricipital‐needle spinneret shows excellent tensile properties (7 MPa tensile stress and 401% breaking elongation), air permeability (85.32 mm s−1) and water vapor permeability (6.7 kg m−2 d−1). Therefore, the electrospinning system with the tricipital‐needle spinneret not only increases the fiber productivity, but also improves the electric field distribution and endows the fibrous membrane with better properties, which can widen the applications of electrospun TPU fibrous membrane and also provides a new approach for the performance design of other electrospun fibers.
{"title":"Effect of improved electric field distribution on jet motion, fiber morphology, and properties of electrospun thermoplastic polyurethane fibrous membrane","authors":"Xiang Li, Liqin Lou","doi":"10.1002/pat.6483","DOIUrl":"https://doi.org/10.1002/pat.6483","url":null,"abstract":"Electric field plays a pivotal role in electrospinning to produce the desired micro and nanofibers, hence, a tricipital‐needle spinneret was developed to improve electric field distribution and productivity in this work. The effects of electric field distribution induced by spinneret configuration on jet motion, fiber morphology, and properties of electrospun TPU fibrous membrane at different applied voltages were investigated by simulation and experiment. The simulation results show that the designed tricipital‐needle spinneret weakens the electric field near the needle tip and strengthens the electric field in the whipping region in comparison to the single‐needle spinneret, exhibiting a relatively uniform electric field distribution. The experimental results demonstrate that the fiber diameter prepared by the tricipital‐needle spinneret at the corresponding voltage is smaller than that of the single‐needle spinneret due to the improved electric field distribution. Moreover, the fibrous membrane prepared by the tricipital‐needle spinneret shows excellent tensile properties (7 MPa tensile stress and 401% breaking elongation), air permeability (85.32 mm s<jats:sup>−1</jats:sup>) and water vapor permeability (6.7 kg m<jats:sup>−2</jats:sup> d<jats:sup>−1</jats:sup>). Therefore, the electrospinning system with the tricipital‐needle spinneret not only increases the fiber productivity, but also improves the electric field distribution and endows the fibrous membrane with better properties, which can widen the applications of electrospun TPU fibrous membrane and also provides a new approach for the performance design of other electrospun fibers.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"21 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangbin Zhang, Lang Xu, Qing Sun, Jian Zhang, Jiawei Sheng
Ceramic polyolefin composites have the capability to transform into hard ceramics when exposed to fire conditions. During the ceramization process, the formation of new crystalline phase plays a crucial role in enhancing flame‐retardant and ceramifiable properties. Consequently, ceramic polyolefin composites show great potential for the applications in fire‐resistant wires and cables. In this article, the incorporation of the compound flame retardant consisting of ammonium polyphosphate/melamine cyanurate/zinc borate (APP/MCA/ZB) was found to enhance the flame retardancy and ceramization of polyethylene/wollastonite fiber/phosphate glass frits (PE/WF/PGF) composites. The results indicated that ceramifiable flame‐retarding PE composites with compound flame retardant exhibited superior flame retardancy compared to pure PE and PE composites with a single flame retardant. Specifically, the limiting oxygen index (LOI) was significantly increased to 26.8%, and the vertical combustion test rating in UL‐94 (test for flammability of plastic materials for parts in devices and appliances) reached V‐0. During the heating process, ZB thermally decomposed to produce 2ZnO ⋅ 3B2O3, which reacted with CaSiO3 to form a silicate glass intermediate phase (CaO ⋅ SiO2 ⋅ 2ZnO ⋅ 3B2O3). APP thermally decomposed to produce (HPO3)n, which reacted with 2ZnO ⋅ 3B2O3 to form a phosphate glass intermediate phase (nP2O5 ⋅ 2ZnO ⋅ 3B2O3). These two glass phases experienced a eutectic reaction with WF, ultimately producing the formation of a new crystalline phase of calcium zinc phosphate (CZP, Ca19Zn2(PO4)14). This newly formed CZP phase made sintered ceramics more compact and had higher flexural strength. The flexural strength of ceramic residues after sintering was 11.68 MPa, meeting the requirements for practical applications.
{"title":"Effect of crystalline phase formed by compound flame retardant on the flame retardancy and ceramization of polyethylene composites","authors":"Xiangbin Zhang, Lang Xu, Qing Sun, Jian Zhang, Jiawei Sheng","doi":"10.1002/pat.6485","DOIUrl":"https://doi.org/10.1002/pat.6485","url":null,"abstract":"Ceramic polyolefin composites have the capability to transform into hard ceramics when exposed to fire conditions. During the ceramization process, the formation of new crystalline phase plays a crucial role in enhancing flame‐retardant and ceramifiable properties. Consequently, ceramic polyolefin composites show great potential for the applications in fire‐resistant wires and cables. In this article, the incorporation of the compound flame retardant consisting of ammonium polyphosphate/melamine cyanurate/zinc borate (APP/MCA/ZB) was found to enhance the flame retardancy and ceramization of polyethylene/wollastonite fiber/phosphate glass frits (PE/WF/PGF) composites. The results indicated that ceramifiable flame‐retarding PE composites with compound flame retardant exhibited superior flame retardancy compared to pure PE and PE composites with a single flame retardant. Specifically, the limiting oxygen index (LOI) was significantly increased to 26.8%, and the vertical combustion test rating in UL‐94 (test for flammability of plastic materials for parts in devices and appliances) reached V‐0. During the heating process, ZB thermally decomposed to produce 2ZnO ⋅ 3B<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, which reacted with CaSiO<jats:sub>3</jats:sub> to form a silicate glass intermediate phase (CaO ⋅ SiO<jats:sub>2</jats:sub> ⋅ 2ZnO ⋅ 3B<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>). APP thermally decomposed to produce (HPO<jats:sub>3</jats:sub>)<jats:sub>n</jats:sub>, which reacted with 2ZnO ⋅ 3B<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> to form a phosphate glass intermediate phase (nP<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> ⋅ 2ZnO ⋅ 3B<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>). These two glass phases experienced a eutectic reaction with WF, ultimately producing the formation of a new crystalline phase of calcium zinc phosphate (CZP, Ca<jats:sub>19</jats:sub>Zn<jats:sub>2</jats:sub>(PO<jats:sub>4</jats:sub>)<jats:sub>14</jats:sub>). This newly formed CZP phase made sintered ceramics more compact and had higher flexural strength. The flexural strength of ceramic residues after sintering was 11.68 MPa, meeting the requirements for practical applications.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"141 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Angelin Swetha, Abhispa Bora, V. Ananthy, Kumar Ponnuchamy, Govarthanan Muthusamy, A. Arun
Plastic is a widely available material in every aspect of life, and its long‐term usage is an important threat to the environment. An enormous quantity of plastic waste has been discharged into the environment throughout the world, resulting in global white pollution. The weathering of accumulated plastic waste in the environment, which can further break down into small fragments like microplastics and nanoplastics, will harm the ecosystem and humans. Therefore, the production and disposal of plastics need to be considered. Bioplastics are increasingly being used as an alternative to conventional plastics; their primary purpose is to solve pollution‐related problems with plastics. Bioplastics (BPs) are an adequate substitute for traditional plastics since they have less carbon footprint and are readily biodegradable, but not all bioplastics can degrade entirely in the natural environment. Due to less environmental impact, bioplastics are defined as polymers produced by using renewable feedstocks or by microorganisms. BP has a wide range of applications in the medical, automotive, and food packaging industries, and it has the potential impact on effect of development of low‐carbon environment. The standards bioplastics must meet to be called compostable or biodegradable are determined by certified worldwide standard processes. The primary purpose of this review is to focus on bioplastics as an alternative tool to plastic—its types, structure, characteristics, degradation behavior, standard techniques, feedstock used for the production of bioplastic, process for its development, and limitation of bioplastics.
{"title":"A review of bioplastics as an alternative to petrochemical plastics: Its types, structure, characteristics, degradation, standards, and feedstocks","authors":"T. Angelin Swetha, Abhispa Bora, V. Ananthy, Kumar Ponnuchamy, Govarthanan Muthusamy, A. Arun","doi":"10.1002/pat.6482","DOIUrl":"https://doi.org/10.1002/pat.6482","url":null,"abstract":"Plastic is a widely available material in every aspect of life, and its long‐term usage is an important threat to the environment. An enormous quantity of plastic waste has been discharged into the environment throughout the world, resulting in global white pollution. The weathering of accumulated plastic waste in the environment, which can further break down into small fragments like microplastics and nanoplastics, will harm the ecosystem and humans. Therefore, the production and disposal of plastics need to be considered. Bioplastics are increasingly being used as an alternative to conventional plastics; their primary purpose is to solve pollution‐related problems with plastics. Bioplastics (BPs) are an adequate substitute for traditional plastics since they have less carbon footprint and are readily biodegradable, but not all bioplastics can degrade entirely in the natural environment. Due to less environmental impact, bioplastics are defined as polymers produced by using renewable feedstocks or by microorganisms. BP has a wide range of applications in the medical, automotive, and food packaging industries, and it has the potential impact on effect of development of low‐carbon environment. The standards bioplastics must meet to be called compostable or biodegradable are determined by certified worldwide standard processes. The primary purpose of this review is to focus on bioplastics as an alternative tool to plastic—its types, structure, characteristics, degradation behavior, standard techniques, feedstock used for the production of bioplastic, process for its development, and limitation of bioplastics.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"52 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cellulose has a wide range of uses. It could be modified to create cellulose‐based hydrophobic materials and cellulose‐based conductive and stable flexible films, but it did not have antibacterial properties and was susceptible to bacterial erosion. In order to improve the utilization of cellulose materials and broaden the application of cellulose materials, cellulose could be given certain antibacterial properties by combining it with antimicrobial agents. This study focused on creating an organic antimicrobial agent, Benzothiocyanine (TCMTB), from CH2ClBr, and then developing a TCMTB‐CMC composite antimicrobial film by combining TCMTB with CMC. The successful synthesis of TCMTB was confirmed through NMR hydrogen spectroscopy testing. By varying the proportions of TCMTB in CMC, three types of composite antimicrobial cellulose film were produced. The study also assessed the impact of TCMTB on the mechanical strength of CMC film and tested the antimicrobial effectiveness of the composite film using the plate counting method. Results showed that the composite film had high inhibition rates, with 96.2% against Escherichia coli and 98.6% against Staphylococcus aureus. To establish a theoretical foundation for its use in seed encapsulation, leather preservation, and other applications.
{"title":"Preparation of benzothiocyanine‐carboxymethyl cellulose composite film and its antimicrobial properties","authors":"Long Wang, Chaojie Li, Xue Li, Zi'ang Xia, Jingxue Yang, Baoming Xu, Heng Zhang","doi":"10.1002/pat.6486","DOIUrl":"https://doi.org/10.1002/pat.6486","url":null,"abstract":"Cellulose has a wide range of uses. It could be modified to create cellulose‐based hydrophobic materials and cellulose‐based conductive and stable flexible films, but it did not have antibacterial properties and was susceptible to bacterial erosion. In order to improve the utilization of cellulose materials and broaden the application of cellulose materials, cellulose could be given certain antibacterial properties by combining it with antimicrobial agents. This study focused on creating an organic antimicrobial agent, Benzothiocyanine (TCMTB), from CH<jats:sub>2</jats:sub>ClBr, and then developing a TCMTB‐CMC composite antimicrobial film by combining TCMTB with CMC. The successful synthesis of TCMTB was confirmed through NMR hydrogen spectroscopy testing. By varying the proportions of TCMTB in CMC, three types of composite antimicrobial cellulose film were produced. The study also assessed the impact of TCMTB on the mechanical strength of CMC film and tested the antimicrobial effectiveness of the composite film using the plate counting method. Results showed that the composite film had high inhibition rates, with 96.2% against Escherichia coli and 98.6% against Staphylococcus aureus. To establish a theoretical foundation for its use in seed encapsulation, leather preservation, and other applications.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"23 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aviation sector is continually seeking ways to reduce the weight of aircraft structures without compromising their mechanical integrity. Lightweight materials, such as advanced epoxy sandwich composites with hybrid nanostructures, have the potential to significantly contribute to fuel efficiency, thereby addressing environmental concerns and operational costs. This research investigates the mechanical properties of hybrid sandwich polymer composites filled with silica nanoparticles (SNiPs). Epoxy isocyanate (PU) foam sandwich composites were fabricated with kevlar fiber, carbon fiber, and glass fiber, constructed by alternating inclined interply bidirectional fiber and foam layers. SNiPs were introduced into the composite system at varying percentages, such as 0, 2, 4, and 6 wt%. The study employs a systematic approach, incorporating experimental testing, to assess key mechanical parameters, including tensile strength, flexural strength, and shear strength. The test results indicate that the incorporation of SNiPs improved the mechanical properties of the composites, leading to enhanced strength, toughness, and modulus of elasticity. Incorporation of composite laminates with 4 wt% SiNPs resulted in improved three‐point bending, tensile, shear, and torsional strengths, with maximum values of ca. 64, ca. 5, ca. 2 MPa, and ca. 22 Nm, respectively. The findings contribute to the ongoing pursuit of materials that can meet the stringent demands of modern aviation, ultimately paving the way for advancements in aircraft construction and design.
{"title":"Nano‐enhanced epoxy sandwich composites: Investigating mechanical properties for future aircraft construction","authors":"Megavannan Mani, M. Thiyagu, Rhoda Afriyie Mensah, Oisik Das, Vigneshwaran Shanmugam","doi":"10.1002/pat.6492","DOIUrl":"https://doi.org/10.1002/pat.6492","url":null,"abstract":"The aviation sector is continually seeking ways to reduce the weight of aircraft structures without compromising their mechanical integrity. Lightweight materials, such as advanced epoxy sandwich composites with hybrid nanostructures, have the potential to significantly contribute to fuel efficiency, thereby addressing environmental concerns and operational costs. This research investigates the mechanical properties of hybrid sandwich polymer composites filled with silica nanoparticles (SNiPs). Epoxy isocyanate (PU) foam sandwich composites were fabricated with kevlar fiber, carbon fiber, and glass fiber, constructed by alternating inclined interply bidirectional fiber and foam layers. SNiPs were introduced into the composite system at varying percentages, such as 0, 2, 4, and 6 wt%. The study employs a systematic approach, incorporating experimental testing, to assess key mechanical parameters, including tensile strength, flexural strength, and shear strength. The test results indicate that the incorporation of SNiPs improved the mechanical properties of the composites, leading to enhanced strength, toughness, and modulus of elasticity. Incorporation of composite laminates with 4 wt% SiNPs resulted in improved three‐point bending, tensile, shear, and torsional strengths, with maximum values of ca. 64, ca. 5, ca. 2 MPa, and ca. 22 Nm, respectively. The findings contribute to the ongoing pursuit of materials that can meet the stringent demands of modern aviation, ultimately paving the way for advancements in aircraft construction and design.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"39 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dominik A. H. Fuchs, Shivani P. Wadgaonkar, Axel H. E. Müller, Holger Frey
The statistical anionic copolymerization of 4‐trimethylsilylstyrene (TMSS) with isoprene (I) in cyclohexane was investigated using in situ near‐infrared (NIR) spectroscopy in the presence of various amounts of the polar modifier tetrahydrofuran (THF). Polymers with narrow molecular weight distribution of 85–138 kg/mol and dispersities of 1.09–1.22 were obtained. By increasing modifier content, the reactivity ratios can be adjusted over a wide range from rTMSS < rI to rTMSS >> rI. Compared to the system styrene/isoprene (S/I) only a minute amount of modifier (0.5 eq THF relative to lithium) is sufficient to alter the reactivity ratios, resulting in an ideally random copolymerization, which validates the higher reactivity of TMSS compared to styrene. Using these reactivity ratios, molar and volume composition gradients were calculated. Additionally, the glass transition temperature and microstructure of the polyisoprene units were investigated via differential scanning calorimetry and proton nuclear magnetic resonance. The results are encouraging for the use of these materials in high‐end applications like membranes.
在不同量的极性改性剂四氢呋喃（THF）存在下，使用原位近红外光谱（NIR）研究了 4-三甲基硅基苯乙烯（TMSS）与异戊二烯（I）在环己烷中的统计阴离子共聚。得到的聚合物分子量分布较窄，为 85-138 kg/mol，分散度为 1.09-1.22。通过增加改性剂的含量，可在 rTMSS < rI 到 rTMSS >> rI 的较大范围内调节反应率。与苯乙烯/异戊二烯（S/I）体系相比，只需极少量的改性剂（相对于锂而言，0.5 eq THF）就足以改变反应活性比，从而实现理想的无规共聚，这也验证了 TMSS 的反应活性高于苯乙烯。利用这些反应活性比计算出了摩尔和体积成分梯度。此外，还通过差示扫描量热法和质子核磁共振法研究了聚异戊二烯单元的玻璃化温度和微观结构。这些结果对于这些材料在膜等高端应用领域的使用是令人鼓舞的。
{"title":"Effect of tetrahydrofuran on the anionic copolymerization of 4‐trimethylsilylstyrene with isoprene","authors":"Dominik A. H. Fuchs, Shivani P. Wadgaonkar, Axel H. E. Müller, Holger Frey","doi":"10.1002/pat.6478","DOIUrl":"https://doi.org/10.1002/pat.6478","url":null,"abstract":"The statistical anionic copolymerization of 4‐trimethylsilylstyrene (TMSS) with isoprene (I) in cyclohexane was investigated using in situ near‐infrared (NIR) spectroscopy in the presence of various amounts of the polar modifier tetrahydrofuran (THF). Polymers with narrow molecular weight distribution of 85–138 kg/mol and dispersities of 1.09–1.22 were obtained. By increasing modifier content, the reactivity ratios can be adjusted over a wide range from <jats:italic>r</jats:italic><jats:sub>TMSS</jats:sub> < <jats:italic>r</jats:italic><jats:sub>I</jats:sub> to <jats:italic>r</jats:italic><jats:sub>TMSS</jats:sub> >> <jats:italic>r</jats:italic><jats:sub>I</jats:sub>. Compared to the system styrene/isoprene (S/I) only a minute amount of modifier (0.5 eq THF relative to lithium) is sufficient to alter the reactivity ratios, resulting in an ideally random copolymerization, which validates the higher reactivity of TMSS compared to styrene. Using these reactivity ratios, molar and volume composition gradients were calculated. Additionally, the glass transition temperature and microstructure of the polyisoprene units were investigated via differential scanning calorimetry and proton nuclear magnetic resonance. The results are encouraging for the use of these materials in high‐end applications like membranes.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"20 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141523183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oreochromis niloticus a Nile tilapia fish is widely used for fish culture practice in many countries for its easy acclimatization and high yield at a short pace of time. Selenium‐chitosan (SeCh) nanoparticles are efficiently used in agriculture, medicine, and aquaculture practices in several studies. The significant approach of Selenium‐Chitosan incorporated fish feed will be evaluated in the present study to achieve the better aquaculture practice in future. In the present study, SeCh nanoparticle was chemically synthesized and incorporated with formulated fish feed. Selenium formulated fish feed contains 31.49 g of carbohydrates and 41.52 g of proteins. SeCh‐fed O. niloticus fingerlings exhibited significantly increased specific growth rates in terms of weight gain, and feed conversion ratio. Chemical characterization of SeChNPs through FTIR spectroscopy indicates the presence of an adjuvant combination of selenium and chitosan presence through functional groups of COO stretch, CH, CC, and CN stretch representing at 3226, 2878, and 1734 cm−1, respectively. Scanning electron microscopy (SEM) and EDX analysis revealed the structural properties of SeChNPs as a fibrous pattern that contains Carbon, Oxygen, and Selenium elements as predominant peak values. SeChNPs incorporated fish feed has higher protein content which is a standard hallmark for a fish feed and an essential prerequisite for fish growth. The formulated SeCh fish feed in the present study is an innovative approach which can be taken further for higher level testing and processing for developing as a better fish feed in terms of feasible and efficient fish growth enhancer.
尼罗罗非鱼（Oreochromis niloticus）因其易于适应和短时间内产量高而被许多国家广泛用于鱼类养殖。在多项研究中，硒-壳聚糖（SeCh）纳米粒子被有效地应用于农业、医药和水产养殖业。本研究将评估硒-壳聚糖掺入鱼饲料的重要方法，以在未来实现更好的水产养殖实践。本研究用化学方法合成了 SeCh 纳米粒子，并将其添加到配方鱼饲料中。硒配方鱼饲料含有 31.49 克碳水化合物和 41.52 克蛋白质。饲喂 SeCh 的黑线鳕幼鱼在增重和饲料转化率方面表现出明显的特定生长率。通过傅立叶变换红外光谱对 SeChNPs 的化学特征进行分析表明，硒和壳聚糖通过分别位于 3226、2878 和 1734 cm-1 的 COO 伸展、CH、CC 和 CN 伸展官能团的存在形成了一种佐剂组合。扫描电子显微镜（SEM）和乙二胺四乙酸（EDX）分析表明，SeChNPs 的结构特性为纤维状，主要峰值含有碳、氧和硒元素。加入 SeChNPs 的鱼饲料蛋白质含量较高，这是鱼饲料的标准标志，也是鱼类生长的必要前提。本研究中配制的 SeCh 鱼饲料是一种创新方法，可进一步进行更高级别的测试和加工，以开发出更好的鱼饲料，成为可行且高效的鱼类生长促进剂。
{"title":"Selenium‐chitosan engineered nanocomposite as efficient formulated fish diet evaluated for sustainable aquaculture practice of Oreochromis niloticus (Nile tilapia) fishes","authors":"Latha Srinivasan, Abinaya Gayathri, Kumaravel Kaliaperumal, Rajasekar Thirunavukkarasu, Arumugam Suresh, Kumaran Subramanian, Sandhanasamy Devanesan, Mohamad S. AlSalhi, Sampath Shobana","doi":"10.1002/pat.6436","DOIUrl":"https://doi.org/10.1002/pat.6436","url":null,"abstract":"<jats:italic>Oreochromis niloticus</jats:italic> a Nile tilapia fish is widely used for fish culture practice in many countries for its easy acclimatization and high yield at a short pace of time. Selenium‐chitosan (SeCh) nanoparticles are efficiently used in agriculture, medicine, and aquaculture practices in several studies. The significant approach of Selenium‐Chitosan incorporated fish feed will be evaluated in the present study to achieve the better aquaculture practice in future. In the present study, SeCh nanoparticle was chemically synthesized and incorporated with formulated fish feed. Selenium formulated fish feed contains 31.49 g of carbohydrates and 41.52 g of proteins. SeCh‐fed <jats:italic>O. niloticus</jats:italic> fingerlings exhibited significantly increased specific growth rates in terms of weight gain, and feed conversion ratio. Chemical characterization of SeChNPs through FTIR spectroscopy indicates the presence of an adjuvant combination of selenium and chitosan presence through functional groups of COO stretch, CH, CC, and CN stretch representing at 3226, 2878, and 1734 cm<jats:sup>−1</jats:sup>, respectively. Scanning electron microscopy (SEM) and EDX analysis revealed the structural properties of SeChNPs as a fibrous pattern that contains Carbon, Oxygen, and Selenium elements as predominant peak values. SeChNPs incorporated fish feed has higher protein content which is a standard hallmark for a fish feed and an essential prerequisite for fish growth. The formulated SeCh fish feed in the present study is an innovative approach which can be taken further for higher level testing and processing for developing as a better fish feed in terms of feasible and efficient fish growth enhancer.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"22 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141188749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Priyanka Kumari, Neeraj Kumari, Chandra Mohan, Mysoon M. Al‐Ansari, Saurav Dixit
The pervasive utilization of plastic as a cost‐effective packaging material for food has led to environmental concerns, primarily due to its non‐biodegradable nature and the ensuing release of carbon dioxide gas that contributes to global warming. In response to these challenges, researchers have shifted their focus toward biopolymers to develop eco‐friendly packaging solutions. The present study introduces a novel approach to study the release of micronutrient (Fe) from clay free starch‐glycerol film and clay‐starch‐glycerol composite film. The structural composition and characteristics of the synthesized film are meticulously examined using x‐ray diffraction (XRD), ATR, scanning electron microscopy and transmission electron microscopy analytical techniques. Notably, XRD analysis reveals a significant interaction between the starch chains and Mt through hydrogen bonding, indicative of starch and glycerol intercalation within the nanoclay gallery—a phenomenon further corroborated by IR spectra analysis. The nanoclay‐infused starch/glycerol composite film exhibits a noteworthy 2.22‐fold increase in water vapor permeability compared to clay free film, attributed to the formation of a convoluted diffusion path indicating the enhancement of the barrier performance of starch‐based films. Comparative evaluations against earlier studies are undertaken to elucidate the advancements in barrier properties, subsequently elucidating the underlying mechanisms through analytical interpretations. From the release study, the release of Fe2+ from the film with clay was observed to be more prolonged compared to a film without clay. As a result, the Montmorillonite clay–polymer composite film was selected for coating rice seeds using the dip‐coating method.
塑料作为一种具有成本效益的食品包装材料，其不可生物降解的特性以及随之释放出的二氧化碳气体导致全球变暖，这些普遍存在的问题引起了人们对环境的关注。为应对这些挑战，研究人员已将重点转向生物聚合物，以开发生态友好型包装解决方案。本研究介绍了一种研究无粘土淀粉-甘油薄膜和粘土-淀粉-甘油复合薄膜释放微量元素（铁）的新方法。利用 X 射线衍射（XRD）、ATR、扫描电子显微镜和透射电子显微镜分析技术对合成薄膜的结构组成和特征进行了细致的研究。值得注意的是，X 射线衍射分析表明，淀粉链与 Mt 之间通过氢键发生了显著的相互作用，这表明淀粉和甘油在纳米粘土画廊中发生了插层--红外光谱分析进一步证实了这一现象。与不含粘土的薄膜相比，注入了纳米粘土的淀粉/甘油复合薄膜的水蒸气渗透性显著提高了 2.22 倍，这归因于形成了一条迂回的扩散路径，表明淀粉基薄膜的阻隔性能得到了提高。与之前的研究进行了比较评估，以阐明阻隔性能的提高，随后通过分析解释阐明了潜在的机制。从释放研究中观察到，与不含粘土的薄膜相比，含粘土的薄膜释放 Fe2+ 的时间更长。因此，我们选择了蒙脱石粘土-聚合物复合薄膜，用于采用浸涂法对水稻种子进行包衣。
{"title":"Augmenting barrier efficiency in clay‐based starch composite films for enhanced packaging sustainability","authors":"Priyanka Kumari, Neeraj Kumari, Chandra Mohan, Mysoon M. Al‐Ansari, Saurav Dixit","doi":"10.1002/pat.6458","DOIUrl":"https://doi.org/10.1002/pat.6458","url":null,"abstract":"The pervasive utilization of plastic as a cost‐effective packaging material for food has led to environmental concerns, primarily due to its non‐biodegradable nature and the ensuing release of carbon dioxide gas that contributes to global warming. In response to these challenges, researchers have shifted their focus toward biopolymers to develop eco‐friendly packaging solutions. The present study introduces a novel approach to study the release of micronutrient (Fe) from clay free starch‐glycerol film and clay‐starch‐glycerol composite film. The structural composition and characteristics of the synthesized film are meticulously examined using x‐ray diffraction (XRD), ATR, scanning electron microscopy and transmission electron microscopy analytical techniques. Notably, XRD analysis reveals a significant interaction between the starch chains and Mt through hydrogen bonding, indicative of starch and glycerol intercalation within the nanoclay gallery—a phenomenon further corroborated by IR spectra analysis. The nanoclay‐infused starch/glycerol composite film exhibits a noteworthy 2.22‐fold increase in water vapor permeability compared to clay free film, attributed to the formation of a convoluted diffusion path indicating the enhancement of the barrier performance of starch‐based films. Comparative evaluations against earlier studies are undertaken to elucidate the advancements in barrier properties, subsequently elucidating the underlying mechanisms through analytical interpretations. From the release study, the release of Fe<jats:sup>2+</jats:sup> from the film with clay was observed to be more prolonged compared to a film without clay. As a result, the Montmorillonite clay–polymer composite film was selected for coating rice seeds using the dip‐coating method.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"82 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141188746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbon nanotubes (CNTs) have aroused great attentions in silicone rubber (SR) composites due to the excellent electrical and mechanical properties. However, the distribution of CNTs is not ideal because of the agglomeration effect of nanomaterials. Incorporating different dimensional nanofillers may be a solution. In this work, two‐dimensional boron nitride (BN) was added to fabricate CNTs/BN/SR composites. The results showed that BN could benefit the dispersion of CNTs and improve the dielectric and mechanical behaviors of the composites. Large dielectric constant (5.35, 92% more than pure SR) with extremely low loss tangent (0.00108) was obtained in the SR composites incorporated with 2 wt% CNTs and 5 wt% BN. High tensile stress (836 kPa) and elongation at break (332%) were also achieved, with a low elastic modulus of 557 kPa. Besides, the CNTs/BN/SR composites had thermal stability up to 400°C. Thus, enhanced dielectric and mechanical properties were achieved in CNTs/BN/SR composites by incorporating different dimensional nanofillers, which have great potential applications in dielectric elastomer composites.
{"title":"Effects of boron nitride nanoplates on the dielectric and mechanical properties of carbon nanotubes/silicone rubber composites","authors":"Yu Zeng, Lu Tang","doi":"10.1002/pat.6463","DOIUrl":"https://doi.org/10.1002/pat.6463","url":null,"abstract":"Carbon nanotubes (CNTs) have aroused great attentions in silicone rubber (SR) composites due to the excellent electrical and mechanical properties. However, the distribution of CNTs is not ideal because of the agglomeration effect of nanomaterials. Incorporating different dimensional nanofillers may be a solution. In this work, two‐dimensional boron nitride (BN) was added to fabricate CNTs/BN/SR composites. The results showed that BN could benefit the dispersion of CNTs and improve the dielectric and mechanical behaviors of the composites. Large dielectric constant (5.35, 92% more than pure SR) with extremely low loss tangent (0.00108) was obtained in the SR composites incorporated with 2 wt% CNTs and 5 wt% BN. High tensile stress (836 kPa) and elongation at break (332%) were also achieved, with a low elastic modulus of 557 kPa. Besides, the CNTs/BN/SR composites had thermal stability up to 400°C. Thus, enhanced dielectric and mechanical properties were achieved in CNTs/BN/SR composites by incorporating different dimensional nanofillers, which have great potential applications in dielectric elastomer composites.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":"67 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141188946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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