Pub Date : 2024-10-02DOI: 10.1080/1023666X.2024.2394225
Victor Ekene Ogbonna , Olawale Popoola , Patricia Popoola
In the present study, the effect of varying titanium dioxide (TiO2) nanoparticles on the dielectric, thermal, and corrosion characteristics of PI-based composites prepared by spark plasma sintering was investigated. The results obtained revealed that the TiO2 nanoparticles were uniformly dispersed within the PI matrix. Addition of TiO2 into the neat PI markedly reduced its dielectric constant and electrical conductivity by 72.7% and 82.3%, respectively, as well as enhancing its breakdown strength by 16.7% at 8 wt% TiO2 loading. The nanocomposites depict better thermal stability and heat-resistance index characteristics when compared to the PI. Additionally, the produced nanocomposites exhibit improved corrosion resistance than that of the neat PI. The remarkable improvement in the dielectric, thermal stability, and corrosion resistance of the nanocomposites is achieved by better dispersion of the TiO2 particles in the polymer matrix. The enhancement in properties suggests TiO2/PI-based nanocomposites potential for a variety of applications in electrical insulation, thermal management, and harsh environment.
{"title":"Effect of titanium dioxide nanoparticles on the dielectric, thermal, and corrosion resistance properties of polyimide (PI) nanocomposites","authors":"Victor Ekene Ogbonna , Olawale Popoola , Patricia Popoola","doi":"10.1080/1023666X.2024.2394225","DOIUrl":"10.1080/1023666X.2024.2394225","url":null,"abstract":"<div><div>In the present study, the effect of varying titanium dioxide (TiO<sub>2</sub>) nanoparticles on the dielectric, thermal, and corrosion characteristics of PI-based composites prepared by spark plasma sintering was investigated. The results obtained revealed that the TiO<sub>2</sub> nanoparticles were uniformly dispersed within the PI matrix. Addition of TiO<sub>2</sub> into the neat PI markedly reduced its dielectric constant and electrical conductivity by 72.7% and 82.3%, respectively, as well as enhancing its breakdown strength by 16.7% at 8 wt% TiO<sub>2</sub> loading. The nanocomposites depict better thermal stability and heat-resistance index characteristics when compared to the PI. Additionally, the produced nanocomposites exhibit improved corrosion resistance than that of the neat PI. The remarkable improvement in the dielectric, thermal stability, and corrosion resistance of the nanocomposites is achieved by better dispersion of the TiO<sub>2</sub> particles in the polymer matrix. The enhancement in properties suggests TiO<sub>2</sub>/PI-based nanocomposites potential for a variety of applications in electrical insulation, thermal management, and harsh environment.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 7","pages":"Pages 533-546"},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1080/1023666X.2024.2383846
K. Beyaz , Y. Abdi , R. Bagtache , M. Trari , A. Benaboura
This study deals with the preparation of a novel biomaterial by incorporating the hematite α-Fe2O3 onto crushed leaves of the Washingtonia filifera palm tree in their raw state and in extracted cellulose from the same plant. The incorporation of α-Fe2O3 was accomplished by hydrothermal route at 200 °C. The palm leaves, extracted cellulose, and synthesized products were characterized by thermal analysis (TG) and FT-IR spectroscopy. The latter revealed peaks at 524 and 449 cm−1 for the synthesized material, attributed to vibrational deformation of the inorganic Fe-O bond. In contrast to the TG profile of raw palm leaves, the thermogram of the composite degrades in a single step at 343 °C. This one-step decomposition clearly indicates the chemical modification of our cellulose matrix and confirms the successful incorporation of the hematite α-Fe2O3 into the lignocellulose. The second part is devoted to α-Fe2O3 working as sensitizer in photocatalysis, it was characterized optically (E g= 1.94 eV) and electrochemically with a flat band potential of −0.53 VSCE. The conduction band (−0.73 VSCE) is more cathodic than the potential of the O2/O2•− couple (−0.52 VSCE) and should reduce dissolved oxygen into reactive O2•− radical. The as-prepared materials were successfully tested in the photocatalytic degradation of Rh B (10 ppm) and the result gave an abatement of 60% on α-Fe2O3/lignocellulose under visible light irradiation (LED lamp) with a flux of 23 mW cm−2. The kinetic obeys a first-order model with a half photocatalytic-life of ∼ 7 h.
{"title":"Hematite (Fe2O3)-modified biopolymer for Rhodamine B degradation under visible light","authors":"K. Beyaz , Y. Abdi , R. Bagtache , M. Trari , A. Benaboura","doi":"10.1080/1023666X.2024.2383846","DOIUrl":"10.1080/1023666X.2024.2383846","url":null,"abstract":"<div><div>This study deals with the preparation of a novel biomaterial by incorporating the hematite α-Fe<sub>2</sub>O<sub>3</sub> onto crushed leaves of the Washingtonia filifera palm tree in their raw state and in extracted cellulose from the same plant. The incorporation of α-Fe<sub>2</sub>O<sub>3</sub> was accomplished by hydrothermal route at 200 °C. The palm leaves, extracted cellulose, and synthesized products were characterized by thermal analysis (TG) and FT-IR spectroscopy. The latter revealed peaks at 524 and 449 cm<sup>−1</sup> for the synthesized material, attributed to vibrational deformation of the inorganic Fe-O bond. In contrast to the TG profile of raw palm leaves, the thermogram of the composite degrades in a single step at 343 °C. This one-step decomposition clearly indicates the chemical modification of our cellulose matrix and confirms the successful incorporation of the hematite α-Fe<sub>2</sub>O<sub>3</sub> into the lignocellulose. The second part is devoted to α-Fe<sub>2</sub>O<sub>3</sub> working as sensitizer in photocatalysis, it was characterized optically (<em>E g</em>= 1.94 eV) and electrochemically with a flat band potential of −0.53 V<sub>SCE</sub>. The conduction band (−0.73 V<em>SCE</em>) is more cathodic than the potential of the O<sub>2</sub>/O<sub>2</sub><sup>•−</sup> couple (−0.52 V<em>SCE</em>) and should reduce dissolved oxygen into reactive O<sub>2</sub><sup>•−</sup> radical. The as-prepared materials were successfully tested in the photocatalytic degradation of Rh B (10 ppm) and the result gave an abatement of 60% on α-Fe<sub>2</sub>O<sub>3</sub>/lignocellulose under visible light irradiation (LED lamp) with a flux of 23 mW cm<sup>−2</sup>. The kinetic obeys a first-order model with a half photocatalytic-life of ∼ 7 h.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 7","pages":"Pages 496-507"},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208274","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}
Pub Date : 2024-10-02DOI: 10.1080/1023666X.2024.2377645
Surjit Kaur , Mithu Maiti Jana
The study of the physico-chemical modification of Yucca filamentosa (Yf) natural fiber by graft copolymerization with ethylmethacrylate using ferrous ammonium sulfate-potassium persulfate as a redox initiator has been reported in the article. Initially, six process parameters; reaction duration, reaction temperature, solvent amount, pH, FAS:KPS ratio, and monomer concentration were used in the study in a sequential experimental design technique, and the significant process variables affecting the yield of the graft copolymer were identified. The Resolution-V design method identified the significant parameters as the reaction temperature, amount of solvent, and the concentration of monomer. In second phase of the study, the screened variables were utilized in the development of a model through the technique of response surface methodology (RSM) for the prediction of the yields, and its optimization. The developed RSM model fitted well with the experimental data, and predicted for the optimal conditions of reactions as temperature 50 °C, solvent 100 ml, and the monomer 3.05 × 10−3 mol/L; at which the highest graft yield percentage obtained was 124.2%. The techniques of FTIR, SEM, and XRD were used for the characterization graft copolymers. Studies of the various physico-chemical properties showed that the produced graft copolymers were more resistant than the natural fibers.
{"title":"Optimization of Yucca filamentosa fiber based graft copolymer through response surface methodology and evaluation of physico-chemical properties","authors":"Surjit Kaur , Mithu Maiti Jana","doi":"10.1080/1023666X.2024.2377645","DOIUrl":"10.1080/1023666X.2024.2377645","url":null,"abstract":"<div><div>The study of the physico-chemical modification of <em>Yucca filamentosa (Yf)</em> natural fiber by graft copolymerization with ethylmethacrylate using ferrous ammonium sulfate-potassium persulfate as a redox initiator has been reported in the article. Initially, six process parameters; reaction duration, reaction temperature, solvent amount, pH, FAS:KPS ratio, and monomer concentration were used in the study in a sequential experimental design technique, and the significant process variables affecting the yield of the graft copolymer were identified. The Resolution-V design method identified the significant parameters as the reaction temperature, amount of solvent, and the concentration of monomer. In second phase of the study, the screened variables were utilized in the development of a model through the technique of response surface methodology (RSM) for the prediction of the yields, and its optimization. The developed RSM model fitted well with the experimental data, and predicted for the optimal conditions of reactions as temperature 50 °C, solvent 100 ml, and the monomer 3.05 × 10<sup>−3 </sup>mol/L; at which the highest graft yield percentage obtained was 124.2%. The techniques of FTIR, SEM, and XRD were used for the characterization graft copolymers. Studies of the various physico-chemical properties showed that the produced graft copolymers were more resistant than the natural fibers.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 7","pages":"Pages 447-464"},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141771070","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}
Pub Date : 2024-09-30DOI: 10.1080/1023666X.2024.2399219
R. Udhayasankar , B. Karthikeyan , K. Murugan , A. Balaji
The development of manufacturing industries is crucial for national progress, with a growing emphasis on green and sustainable practices. This study investigates the development and performance of hybrid polymer composites based on poly lactic acid (PLA) reinforced with lignocellulosic fillers: bagasse fiber (BF), tamarind seed fiber (TSF), Terminalia chebula fiber (TCF), and a hybrid filler of bagasse, tamarind seed, and Terminalia chebula (BTSTCF). Five types of composites were fabricated with varying filler compositions: PLA, PLA/BF, PLA/TSF, PLA/TCF, and PLA/BTSTCF, consisting of 30% BF, TSF, or TCF with 70% PLA, and an additional 10% of each filler in the BTSTCF composite. The results demonstrated that the PLA/BTSTCF hybrid composite outperformed others regarding mechanical strength, thermal stability, and interfacial adhesion. Specifically, it exhibited superior flexural strength, impact strength, and tensile strength. The findings indicate that incorporating a combination of bagasse, tamarind seed, and Terminalia chebula fillers into PLA significantly enhances its properties and performance. This study contributes to advancing sustainable and green manufacturing practices and holds promise for economic growth through the development of high-performance, eco-friendly materials.
{"title":"Hybrid polymer composites of Terminalia chebula filler reinforced thermal and mechanical characterization of bagasse/tamarind seed","authors":"R. Udhayasankar , B. Karthikeyan , K. Murugan , A. Balaji","doi":"10.1080/1023666X.2024.2399219","DOIUrl":"10.1080/1023666X.2024.2399219","url":null,"abstract":"<div><div>The development of manufacturing industries is crucial for national progress, with a growing emphasis on green and sustainable practices. This study investigates the development and performance of hybrid polymer composites based on poly lactic acid (PLA) reinforced with lignocellulosic fillers: bagasse fiber (BF), tamarind seed fiber (TSF), <em>Terminalia chebula</em> fiber (TCF), and a hybrid filler of bagasse, tamarind seed, and <em>Terminalia chebula</em> (BTSTCF). Five types of composites were fabricated with varying filler compositions: PLA, PLA/BF, PLA/TSF, PLA/TCF, and PLA/BTSTCF, consisting of 30% BF, TSF, or TCF with 70% PLA, and an additional 10% of each filler in the BTSTCF composite. The results demonstrated that the PLA/BTSTCF hybrid composite outperformed others regarding mechanical strength, thermal stability, and interfacial adhesion. Specifically, it exhibited superior flexural strength, impact strength, and tensile strength. The findings indicate that incorporating a combination of bagasse, tamarind seed, and <em>Terminalia chebula</em> fillers into PLA significantly enhances its properties and performance. This study contributes to advancing sustainable and green manufacturing practices and holds promise for economic growth through the development of high-performance, eco-friendly materials.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 8","pages":"Pages 618-634"},"PeriodicalIF":1.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592608","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}
Pub Date : 2024-09-26DOI: 10.1080/1023666X.2024.2404906
Jitendra Kumar , Sushant Negi
Syntactic foam composite (SFC) has the potential to substitute the conventional material used in damage-tolerance, thermal insulation, and weight-sensitive applications such as automotive parts, submarine structures, etc. Here, SFCs were developed by varying the weight fraction of cenosphere (CS) content from 0-40 wt. % in a polyethylene terephthalate glycol (PETG) matrix. This investigation provides the terse behavior of the viscoelastic properties of 3D-printed PETG/CS foam composites. The thermogravimetric analysis (TGA) results showed that the initial degradation temperature (Ti) and the temperature at 50% mass loss (T50) of the composite filament increased with the addition of CS particles, indicating improved thermal stability. The dynamic mechanical analysis (DMA) results revealed that the storage modulus of SFC increased with increasing cenosphere content. The foam composite’s glass transition temperature (78.9 ± 0.35 °C) is lower by 4 °C than pure PETG. This underscores the potential of the developed syntactic foam composite to effectively utilize industrial waste fly ash through 3D printing routine, thereby promoting sustainable manufacturing practices.
{"title":"Dynamic mechanical analysis of additively manufactured cenosphere-filled PETG syntactic foam composite","authors":"Jitendra Kumar , Sushant Negi","doi":"10.1080/1023666X.2024.2404906","DOIUrl":"10.1080/1023666X.2024.2404906","url":null,"abstract":"<div><div>Syntactic foam composite (SFC) has the potential to substitute the conventional material used in damage-tolerance, thermal insulation, and weight-sensitive applications such as automotive parts, submarine structures, etc. Here, SFCs were developed by varying the weight fraction of cenosphere (CS) content from 0-40 wt. % in a polyethylene terephthalate glycol (PETG) matrix. This investigation provides the terse behavior of the viscoelastic properties of 3D-printed PETG/CS foam composites. The thermogravimetric analysis (TGA) results showed that the initial degradation temperature (T<sub>i</sub>) and the temperature at 50% mass loss (T<sub>50</sub>) of the composite filament increased with the addition of CS particles, indicating improved thermal stability. The dynamic mechanical analysis (DMA) results revealed that the storage modulus of SFC increased with increasing cenosphere content. The foam composite’s glass transition temperature (78.9 ± 0.35 °C) is lower by 4 °C than pure PETG. This underscores the potential of the developed syntactic foam composite to effectively utilize industrial waste fly ash through 3D printing routine, thereby promoting sustainable manufacturing practices.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 8","pages":"Pages 647-657"},"PeriodicalIF":1.7,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592612","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}
Pub Date : 2024-09-17DOI: 10.1080/1023666X.2024.2398152
Sumbal Anwar , Saad Liaqat , Riaz Ullah , Zafar Iqbal , Fozia Rahman , Essam A. Ali , Umar Nishan , Sandleen Feroz , Nawshad Muhammad
This study aims to determine and compare the dimensional stability, setting time, tensile strength, and rheological properties of kaolin clay powder-modified and unmodified alginate impression material. Commercially available alginate-based impression material was considered as a control (C) while experimental groups E-1, E-2, and E-3 were fabricated by adding 2%, 4%, and 8% of kaolin clay powder in the control, respectively. Analytical techniques were used for the characterization of the samples. A tensile strength, rheological property, dimensional stability, and setting time were recorded for control and experimental groups. FTIR analysis confirmed the presence of kaolin clay powder in all experimental groups. SEM showed a round solid structure and irregular shape particle appearance in all experimental groups as well as a control group. The dimensional stability was improved by the addition of kaolin clay powder to the alginate impression material. The percentage dimensional change at 5 min, 6, and 12 h was increased for E3 adding (8% kaolin clay powder) and decreased for the control group. The mean value of tensile strength was highest for E3 followed by E2, E1, and least in control groups. Higher Young’s Modulus and lower deformation values were measured for E3. The mean value of setting time was highest for E3 and the least was in the control group. The results for both setting time and tensile strength were very highly statistically significant (p < 0.001). The mean values of viscoelasticity, flow, and drip test were increased statistically by adding various concentrations of kaolin clay powder to the alginate impression material.
{"title":"Evaluation of dimensional stability, setting time, tensile strength, and rheological properties of kaolin clay incorporated alginate impression material","authors":"Sumbal Anwar , Saad Liaqat , Riaz Ullah , Zafar Iqbal , Fozia Rahman , Essam A. Ali , Umar Nishan , Sandleen Feroz , Nawshad Muhammad","doi":"10.1080/1023666X.2024.2398152","DOIUrl":"10.1080/1023666X.2024.2398152","url":null,"abstract":"<div><div>This study aims to determine and compare the dimensional stability, setting time, tensile strength, and rheological properties of kaolin clay powder-modified and unmodified alginate impression material. Commercially available alginate-based impression material was considered as a control (C) while experimental groups E-1, E-2, and E-3 were fabricated by adding 2%, 4%, and 8% of kaolin clay powder in the control, respectively. Analytical techniques were used for the characterization of the samples. A tensile strength, rheological property, dimensional stability, and setting time were recorded for control and experimental groups. FTIR analysis confirmed the presence of kaolin clay powder in all experimental groups. SEM showed a round solid structure and irregular shape particle appearance in all experimental groups as well as a control group. The dimensional stability was improved by the addition of kaolin clay powder to the alginate impression material. The percentage dimensional change at 5 min, 6, and 12 h was increased for E3 adding (8% kaolin clay powder) and decreased for the control group. The mean value of tensile strength was highest for E3 followed by E2, E1, and least in control groups. Higher Young’s Modulus and lower deformation values were measured for E3. The mean value of setting time was highest for E3 and the least was in the control group. The results for both setting time and tensile strength were very highly statistically significant (<em>p</em> < 0.001). The mean values of viscoelasticity, flow, and drip test were increased statistically by adding various concentrations of kaolin clay powder to the alginate impression material.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 8","pages":"Pages 602-617"},"PeriodicalIF":1.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592609","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}
This article deals with the impact of short glass fiber (GF) on the performance of 60/40 wt% of polyamide 6/polyamide 12 (PA6/PA12) blend. The short fiber-reinforced composites were fabricated by using melt compounding via twin screw extruder and injection molding. The morphological, water uptake, rheological, thermo-mechanical, and mechanical properties of the composites were discussed. The morphological observations show that the PA6/PA12 blend exhibited compatible morphology and also adhesion between the fiber and matrix was quite strong. The tensile strength/modulus and storage modulus of the blend were substantially improved with GF reinforcement as a result of these morphological findings. While the water uptake of neat PA6 decreased significantly after blending with PA12, the incorporation of GF further reduced the water uptake of the PA6/PA12 blend. The thermomechanical analysis showed the enhancement of the stiffness of the composites and also glass transition temperature increment.
{"title":"Fabrication and performance of short glass fiber reinforced polyamide composites","authors":"Bedriye Ucpinar Durmaz , Elnura Artykbaeva , Ayse Aytac","doi":"10.1080/1023666X.2024.2394222","DOIUrl":"10.1080/1023666X.2024.2394222","url":null,"abstract":"<div><div>This article deals with the impact of short glass fiber (GF) on the performance of 60/40 wt% of polyamide 6/polyamide 12 (PA6/PA12) blend. The short fiber-reinforced composites were fabricated by using melt compounding via twin screw extruder and injection molding. The morphological, water uptake, rheological, thermo-mechanical, and mechanical properties of the composites were discussed. The morphological observations show that the PA6/PA12 blend exhibited compatible morphology and also adhesion between the fiber and matrix was quite strong. The tensile strength/modulus and storage modulus of the blend were substantially improved with GF reinforcement as a result of these morphological findings. While the water uptake of neat PA6 decreased significantly after blending with PA12, the incorporation of GF further reduced the water uptake of the PA6/PA12 blend. The thermomechanical analysis showed the enhancement of the stiffness of the composites and also glass transition temperature increment.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 8","pages":"Pages 589-601"},"PeriodicalIF":1.7,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592611","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}
Pub Date : 2024-09-11DOI: 10.1080/1023666X.2024.2399791
Fengju Shang , Jiaqing Zhang , Taiyun Zhu , Yi Guo , Yabin Fan , Shouwang Tao , Rui Liu , Yanming Ding
To determine the thermal kinetic triplets and elucidate the reaction mechanism of thin intumescent fire-retardant coatings (IFR) of steel structures, one efficient combined kinetic approach was implemented in this study. Thermogravimetric experiments were conducted in air atmosphere at four heating rates, and the whole IFR thermal degradation process was divided into two stages. The average activation energy values derived by model-free methods were 78.9 kJ/mol and 175.16 kJ/mol for Stage I (0<α < 0.2) and Stage II (0.2<α < 0.9), respectively. Furthermore, the linear Coats-Redfern (CR) and non-linear Masterplots models were applied to identify the possible reaction mechanism. It was found that the F3/2 mechanistic model was better suited to the main thermal degradation process. Then model reconstruction based on the F3/2 mechanism model was performed. The results showed that the reconstructed model had a strict linear relationship in the independence analysis and KCE analysis, along with a good agreement between the theoretical and experimental results. The current study provided new insights into the systematic thermal degradation mechanism of IFR, and the proposed kinetic model would be helpful for the thermal protection prediction for steel structure during fire.
{"title":"Combined kinetic analysis of thermal degradation characteristics and reaction mechanism of thin intumescent fire-retardant coating of steel structure","authors":"Fengju Shang , Jiaqing Zhang , Taiyun Zhu , Yi Guo , Yabin Fan , Shouwang Tao , Rui Liu , Yanming Ding","doi":"10.1080/1023666X.2024.2399791","DOIUrl":"10.1080/1023666X.2024.2399791","url":null,"abstract":"<div><div>To determine the thermal kinetic triplets and elucidate the reaction mechanism of thin intumescent fire-retardant coatings (IFR) of steel structures, one efficient combined kinetic approach was implemented in this study. Thermogravimetric experiments were conducted in air atmosphere at four heating rates, and the whole IFR thermal degradation process was divided into two stages. The average activation energy values derived by model-free methods were 78.9 kJ/mol and 175.16 kJ/mol for Stage I (0<<em>α</em> < 0.2) and Stage II (0.2<<em>α</em> < 0.9), respectively. Furthermore, the linear Coats-Redfern (CR) and non-linear Masterplots models were applied to identify the possible reaction mechanism. It was found that the F3/2 mechanistic model was better suited to the main thermal degradation process. Then model reconstruction based on the F3/2 mechanism model was performed. The results showed that the reconstructed model had a strict linear relationship in the independence analysis and KCE analysis, along with a good agreement between the theoretical and experimental results. The current study provided new insights into the systematic thermal degradation mechanism of IFR, and the proposed kinetic model would be helpful for the thermal protection prediction for steel structure during fire.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 8","pages":"Pages 635-646"},"PeriodicalIF":1.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592613","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}
Pub Date : 2024-07-18DOI: 10.1080/1023666X.2024.2378894
Sara A. Alqarni
Poly (1,4-phenylene ether ether sulfone) (PEES) is a commonly used polymer in membrane technology for water treatment applications such as water purification and blood dialyzing in hemodialysis. In this study, PEES was chemically modified by nitration, yielding nitrated Poly (1,4-phenylene ether ether sulfone) (NPEES). Following that, NPEES nanocomposites (NCs) comprise multi-walled carbon nanotubes (MWCNTs), and the process involved the synthesis of reduced graphene oxide-oxidized single-walled carbon nanotubes, abbreviated as reduced (GO-oxSWCNTs). Various characterization techniques were used on the created membranes, such as Fourier-transform infrared spectroscopy (AT-FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. All polymer nanocomposites were found to be amorphous, according to the XRD patterns. SEM scans revealed random crater-like features on the surface of NPEES, but MWCNTs and reduced (GO-oxSWCNTs) NCs were distributed evenly on the polymer surface. The primary goal of this study was to evaluate the antimicrobial activity of modified NPEES membranes against two Gram-positive bacteria, Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis), two Gram-negative bacteria, Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), and a fungus, Candida albicans (C. albicans). All modified membranes, including NPEES, NPEES/MWCNTs NCs, and NPEES/MWCNTs/reduced (GO-oxSWCNTs) NCs, exhibited antibacterial activity against S. aureus and B. subtilis. Notably, when compared to NPEES/MWCNTs NCs and NPEES/MWCNTs/reduced (GO-oxSWCNTs) NCs, the NPEES membrane had higher antibacterial activity, generating a 12 mm inhibitory zone. Furthermore, molecular docking studies revealed a strong fit of the tested polymer nanocomposites into the DNA gyrase B active site (PDB ID: 4uro), which was consistent with the practical results of their antibacterial activity evaluation.
{"title":"Fabrication of poly (1,4-phenylene ether ether sulfone) modified with MWCNTs/reduced (GO-oxSWCNTs) NCs for enhanced antimicrobial activities","authors":"Sara A. Alqarni","doi":"10.1080/1023666X.2024.2378894","DOIUrl":"10.1080/1023666X.2024.2378894","url":null,"abstract":"<div><p>Poly (1,4-phenylene ether ether sulfone) (PEES) is a commonly used polymer in membrane technology for water treatment applications such as water purification and blood dialyzing in hemodialysis. In this study, PEES was chemically modified by nitration, yielding nitrated Poly (1,4-phenylene ether ether sulfone) (NPEES). Following that, NPEES nanocomposites (NCs) comprise multi-walled carbon nanotubes (MWCNTs), and the process involved the synthesis of reduced graphene oxide-oxidized single-walled carbon nanotubes, abbreviated as reduced (GO-oxSWCNTs). Various characterization techniques were used on the created membranes, such as Fourier-transform infrared spectroscopy (AT-FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. All polymer nanocomposites were found to be amorphous, according to the XRD patterns. SEM scans revealed random crater-like features on the surface of NPEES, but MWCNTs and reduced (GO-oxSWCNTs) NCs were distributed evenly on the polymer surface. The primary goal of this study was to evaluate the antimicrobial activity of modified NPEES membranes against two Gram-positive bacteria, <em>Staphylococcus aureus</em> (S. aureus) and <em>Bacillus subtilis</em> (B. subtilis), two Gram-negative bacteria, <em>Pseudomonas aeruginosa</em> (P. aeruginosa) and <em>Escherichia coli</em> (E. coli), and a fungus, <em>Candida albicans</em> (C. albicans). All modified membranes, including NPEES, NPEES/MWCNTs NCs, and NPEES/MWCNTs/reduced (GO-oxSWCNTs) NCs, exhibited antibacterial activity against <em>S. aureus</em> and <em>B. subtilis</em>. Notably, when compared to NPEES/MWCNTs NCs and NPEES/MWCNTs/reduced (GO-oxSWCNTs) NCs, the NPEES membrane had higher antibacterial activity, generating a 12 mm inhibitory zone. Furthermore, molecular docking studies revealed a strong fit of the tested polymer nanocomposites into the DNA gyrase B active site (PDB ID: 4uro), which was consistent with the practical results of their antibacterial activity evaluation.</p></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 6","pages":"Pages 429-446"},"PeriodicalIF":1.7,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742196","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}
Pub Date : 2024-07-16DOI: 10.1080/1023666X.2024.2377648
Hind Guemmour , Djaffar Kheffache , Nawal Khier
Starch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix.
{"title":"Sustainable starch-based bioplastics reinforced with carob filler: characterization and biodegradability assessments","authors":"Hind Guemmour , Djaffar Kheffache , Nawal Khier","doi":"10.1080/1023666X.2024.2377648","DOIUrl":"10.1080/1023666X.2024.2377648","url":null,"abstract":"<div><p>Starch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix.</p></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":"29 6","pages":"Pages 410-428"},"PeriodicalIF":1.7,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742197","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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