In the research, a bio‐based through epoxidizing, plasticizer was created non‐toxic custard apple seed oil (CASO) using peroxy acid generated in situ and investigates the application of a bio‐based plasticizer in the compounding of polyvinyl chloride as epoxidized custard apple seed oil (ECASO) (PVC). The ECASO was synthesized through an epoxidation reaction and characterized using Fourier‐transform infrared spectroscopy and analytical parameters such as epoxy value, and oxirane conversion. To create plasticized PVC, the PVC was mixed with different ratios of ECASO and dioctyl phthalate (DOP) using a two‐roll mill and prepared PVC sheet by compression molding. The ECASO plasticizer completely fuses with PVC and plasticized PVC sheets are made. Glass transition temperature, tensile strength, percent elongation, solvent resistance, differential scanning calorimetry (DSC), and thermal gravimetric analysis were among the mechanical and thermal characteristics of PVC sheets that were assessed. This result shows the plasticization efficiency of ECASO and DOP combined was similar to that of DOP alone, even with the same plasticizer loading. Moreover, when used in combination with DOP, ECASO was found to be a more efficient plasticizer. As a result, ECASO can be used as a biobased substitute for DOP, replacing up to 60% of the ECASO plasticizer loading.
{"title":"Synthesis of bio‐based plasticizer from custard apple seed oil for PVC application","authors":"Baburao M. Kharat, A. More","doi":"10.1002/vjch.202300340","DOIUrl":"https://doi.org/10.1002/vjch.202300340","url":null,"abstract":"In the research, a bio‐based through epoxidizing, plasticizer was created non‐toxic custard apple seed oil (CASO) using peroxy acid generated in situ and investigates the application of a bio‐based plasticizer in the compounding of polyvinyl chloride as epoxidized custard apple seed oil (ECASO) (PVC). The ECASO was synthesized through an epoxidation reaction and characterized using Fourier‐transform infrared spectroscopy and analytical parameters such as epoxy value, and oxirane conversion. To create plasticized PVC, the PVC was mixed with different ratios of ECASO and dioctyl phthalate (DOP) using a two‐roll mill and prepared PVC sheet by compression molding. The ECASO plasticizer completely fuses with PVC and plasticized PVC sheets are made. Glass transition temperature, tensile strength, percent elongation, solvent resistance, differential scanning calorimetry (DSC), and thermal gravimetric analysis were among the mechanical and thermal characteristics of PVC sheets that were assessed. This result shows the plasticization efficiency of ECASO and DOP combined was similar to that of DOP alone, even with the same plasticizer loading. Moreover, when used in combination with DOP, ECASO was found to be a more efficient plasticizer. As a result, ECASO can be used as a biobased substitute for DOP, replacing up to 60% of the ECASO plasticizer loading.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140700808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this article, a TiO2/reduced graphene oxide (rGO) composite was synthesized from rGO and soluble titanium hydroxide‐peroxide complexes. The obtained materials were characterized by X‐ray diffraction, scanning electron microscopy, nitrogen adsorption/desorption, Raman spectroscopy and energy dispersive X‐ray spectroscopy‐elementary mapping. The TiO2/rGO composite was used as an electrode modifier for developing an electrochemical sensor to simultaneous analysis of Cd(II) and Pb(II) by using differential pulse anodic stripping voltammetry (DP‐ASV). Under optimal conditions, the linear correlation between the stripping peak current and the metal ion concentration is good in the range of 5–100 ppb for both metals (R2 ≥ 0.998), and a low detection limit (3.17 ppb for Cd(II) and 2.42 ppb for Pb(II)) was obtained. The interference study revealed that some metal cations had little influence on the DP‐ASV signals of Cd(II) and Pb(II). In addition, the developed electrode exhibited satisfied reproducibility and repeatability. The TiO2/rGO‐modified electrode was tested toward the detection of Cd(II) and Pb(II) in river waters and the obtained exceptional recoveries and results were further associated with AAS results. This study indicates that the TiO2/rGO composite might be an alternative for practical applications in the electrochemical determination of heavy metal ions in aquatic solutions.
{"title":"Voltammetry determination of Cd(II) and Pb(II) at TiO2/reduced graphene oxide modified electrodes","authors":"N. Luyen, Tran Thanh Tam Toan, Nguyen Mau Thanh","doi":"10.1002/vjch.202300303","DOIUrl":"https://doi.org/10.1002/vjch.202300303","url":null,"abstract":"In this article, a TiO2/reduced graphene oxide (rGO) composite was synthesized from rGO and soluble titanium hydroxide‐peroxide complexes. The obtained materials were characterized by X‐ray diffraction, scanning electron microscopy, nitrogen adsorption/desorption, Raman spectroscopy and energy dispersive X‐ray spectroscopy‐elementary mapping. The TiO2/rGO composite was used as an electrode modifier for developing an electrochemical sensor to simultaneous analysis of Cd(II) and Pb(II) by using differential pulse anodic stripping voltammetry (DP‐ASV). Under optimal conditions, the linear correlation between the stripping peak current and the metal ion concentration is good in the range of 5–100 ppb for both metals (R2 ≥ 0.998), and a low detection limit (3.17 ppb for Cd(II) and 2.42 ppb for Pb(II)) was obtained. The interference study revealed that some metal cations had little influence on the DP‐ASV signals of Cd(II) and Pb(II). In addition, the developed electrode exhibited satisfied reproducibility and repeatability. The TiO2/rGO‐modified electrode was tested toward the detection of Cd(II) and Pb(II) in river waters and the obtained exceptional recoveries and results were further associated with AAS results. This study indicates that the TiO2/rGO composite might be an alternative for practical applications in the electrochemical determination of heavy metal ions in aquatic solutions.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140702919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nguyen Manh Khoa, Nguyen Thi Thu, Tran Thi Hien, Vu Thi Diep, Ha Thuy Trang, Do Hong Manh, Nguyen Hoang Tuan, Do Thi Ha
The bioassay‐guided isolation of compounds from the aerial parts of Isodon lophanthoides (IL) resulted in the identification of five compounds (1–5). The chemical structures of 1–5 were determined through spectral analyses and compared to those identified in the literature to be 4‐hydroxybenzoic acid (1), protocatechuic acid (2), rosmarinic acid (3), coetsoidin B (4), and coetsoidin A (5). Compounds 1, 4, and 5 were found for the first time in the aerial parts of IL. Compounds 1 and 2 displayed potent cytotoxic activity against A549, MCF‐7, HepG2, and HL60 cancer cell lines, with IC50 values ranging from 13.93 to 18.69 µm and from 11.97 to 18.30 µm, respectively. Compounds 1‒5 significantly inhibited LPS‐induced IL‐1β production in RAW 264.7 macrophages compared to the LPS 5 ng/mL control group, resulting in IL‐1β concentrations ranging from 34.92 to 46.91 pg/mL. Additionally, compounds 1‒5 exhibited notable stimulation of IL‐10 production, with IL‐10 levels ranging from 358.77 to 478.23 pg/mL, compared to the LPS 5 ng/mL control group. These findings highlight the potential of compounds 1‒5 and the IL extracts for the cytotoxic effects on cancer cell lines and on LPS‐induced IL‐1β and IL‐10 production in RAW 264.7 macrophages.
{"title":"Compounds from aerial parts of Isodon lophanthoides and their effects of cytotoxicity and LPS‐induced IL‐1β and IL‐10 production in RAW 264.7 macrophages","authors":"Nguyen Manh Khoa, Nguyen Thi Thu, Tran Thi Hien, Vu Thi Diep, Ha Thuy Trang, Do Hong Manh, Nguyen Hoang Tuan, Do Thi Ha","doi":"10.1002/vjch.202300218","DOIUrl":"https://doi.org/10.1002/vjch.202300218","url":null,"abstract":"The bioassay‐guided isolation of compounds from the aerial parts of Isodon lophanthoides (IL) resulted in the identification of five compounds (1–5). The chemical structures of 1–5 were determined through spectral analyses and compared to those identified in the literature to be 4‐hydroxybenzoic acid (1), protocatechuic acid (2), rosmarinic acid (3), coetsoidin B (4), and coetsoidin A (5). Compounds 1, 4, and 5 were found for the first time in the aerial parts of IL. Compounds 1 and 2 displayed potent cytotoxic activity against A549, MCF‐7, HepG2, and HL60 cancer cell lines, with IC50 values ranging from 13.93 to 18.69 µm and from 11.97 to 18.30 µm, respectively. Compounds 1‒5 significantly inhibited LPS‐induced IL‐1β production in RAW 264.7 macrophages compared to the LPS 5 ng/mL control group, resulting in IL‐1β concentrations ranging from 34.92 to 46.91 pg/mL. Additionally, compounds 1‒5 exhibited notable stimulation of IL‐10 production, with IL‐10 levels ranging from 358.77 to 478.23 pg/mL, compared to the LPS 5 ng/mL control group. These findings highlight the potential of compounds 1‒5 and the IL extracts for the cytotoxic effects on cancer cell lines and on LPS‐induced IL‐1β and IL‐10 production in RAW 264.7 macrophages.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140721309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eman Mohamed Abdel Hamid, Ramez Rafik Maher, Ahmed Sherif Ahmed, Yousif Mohamed Yousif, Mohamed Samir Abdel Fatah, Abdel Wahab Mohamed Abdel Wahab, Shady Sami Ali
Around 21.7 million tons of urban solid waste are produced in North Africa and the Middle East. The amount of glass waste produced is 0.87 million tons. The amount of urban glass waste (UGW) produced in Egypt was 2280.8 tons per day. This paper aims to study the effect of partial replacement of UGW in the production of ceramic floor tiles to save the production cost and raw materials. The characteristics of the basic raw mixture of floor tiles and UGW were studied. The waste was collected, crushed and ground to be blended with the basic mixture in different percentages that ranged from 0 to 35%. The specimens were molded under uniaxial pressure followed by drying and firing at temperatures ranging from 1050 to 1120 °C. The characteristics of the fired specimens have been determined and compared with the International Standard Limits. The results showed that specimens containing waste ranging from 25% to 35%, fired at 1100 °C with a soaking time of 15 min have a modulus of rupture of 18.9 to 19.7 MPa, breaking strength of 600 to 613N and water absorption of 9.78% to 8.2% respectively that fulfilled the lowest requirements for the ISO 13006 for dry pressed tiles Group BIIb.
{"title":"Recycling of urban glass waste in ceramic floor tiles toward sustainability","authors":"Eman Mohamed Abdel Hamid, Ramez Rafik Maher, Ahmed Sherif Ahmed, Yousif Mohamed Yousif, Mohamed Samir Abdel Fatah, Abdel Wahab Mohamed Abdel Wahab, Shady Sami Ali","doi":"10.1002/vjch.202300237","DOIUrl":"https://doi.org/10.1002/vjch.202300237","url":null,"abstract":"Around 21.7 million tons of urban solid waste are produced in North Africa and the Middle East. The amount of glass waste produced is 0.87 million tons. The amount of urban glass waste (UGW) produced in Egypt was 2280.8 tons per day. This paper aims to study the effect of partial replacement of UGW in the production of ceramic floor tiles to save the production cost and raw materials. The characteristics of the basic raw mixture of floor tiles and UGW were studied. The waste was collected, crushed and ground to be blended with the basic mixture in different percentages that ranged from 0 to 35%. The specimens were molded under uniaxial pressure followed by drying and firing at temperatures ranging from 1050 to 1120 °C. The characteristics of the fired specimens have been determined and compared with the International Standard Limits. The results showed that specimens containing waste ranging from 25% to 35%, fired at 1100 °C with a soaking time of 15 min have a modulus of rupture of 18.9 to 19.7 MPa, breaking strength of 600 to 613N and water absorption of 9.78% to 8.2% respectively that fulfilled the lowest requirements for the ISO 13006 for dry pressed tiles Group BIIb.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140725227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nguyen Van Chien, Dao Hai Yen, Hoang Thi Phuong, Phạm Quynh Trang, Nguyen Thi Diep, Tran Huu Huy, Pham Thi Phuong, Phung Thi Anh Tuyet
The thermoplastic chitosan/starch material was prepared through the utilization of melt mixing in this research. The chitosan/starch compound is plasticized using a mixture of glycerol and ethylene glycol in a ratio of 2:1. The present study evaluated the impact of chitosan concentration on the structural and material properties through the utilization of various analytical techniques, including X‐ray diffraction, Fourier transformative infrared spectroscopy, scanning optical microscopy, water absorption, and mechanical properties. The utilization of SOM imaging revealed that the dispersion of chitosan within the starch phase was homogeneous when the chitosan content was below 9%. The study findings indicated that the incorporation of chitosan into thermoplastic chitosan/starch material resulted in a decrease in moisture absorption under varying humidity conditions (52%, 75%, and 85% RH). The results indicated that the material's hidden absorption is comparable in both environments, with a saturated moisture absorption range of 19%–25%. However, the material exhibited a significantly higher level of humidification at RH 85%, with an interaction range of 40%–48%. Furthermore, the findings suggested that an increase in chitosan content was positively correlated with an increase in tensile strength while negatively correlated with elongation at break.
本研究利用熔融混合法制备了热塑性壳聚糖/淀粉材料。壳聚糖/淀粉化合物是用甘油和乙二醇以 2:1 的比例混合塑化而成的。本研究利用各种分析技术，包括 X 射线衍射、傅立叶变换红外光谱、扫描光学显微镜、吸水率和机械性能，评估了壳聚糖浓度对结构和材料性能的影响。利用 SOM 成像显示，当壳聚糖含量低于 9% 时，壳聚糖在淀粉相中的分散是均匀的。研究结果表明，在不同的湿度条件（52%、75% 和 85% RH）下，将壳聚糖加入热塑性壳聚糖/淀粉材料中会降低吸湿性。结果表明，材料在这两种环境下的隐蔽吸湿性相当，饱和吸湿范围为 19%-25%。然而，在相对湿度为 85% 时，该材料的增湿效果明显更强，相互作用范围为 40%-48%。此外，研究结果表明，壳聚糖含量的增加与拉伸强度的增加呈正相关，而与断裂伸长率呈负相关。
{"title":"Preparation of bioplastic materials based on thermoplastic chitosan and starch by melting mixing method","authors":"Nguyen Van Chien, Dao Hai Yen, Hoang Thi Phuong, Phạm Quynh Trang, Nguyen Thi Diep, Tran Huu Huy, Pham Thi Phuong, Phung Thi Anh Tuyet","doi":"10.1002/vjch.202300290","DOIUrl":"https://doi.org/10.1002/vjch.202300290","url":null,"abstract":"The thermoplastic chitosan/starch material was prepared through the utilization of melt mixing in this research. The chitosan/starch compound is plasticized using a mixture of glycerol and ethylene glycol in a ratio of 2:1. The present study evaluated the impact of chitosan concentration on the structural and material properties through the utilization of various analytical techniques, including X‐ray diffraction, Fourier transformative infrared spectroscopy, scanning optical microscopy, water absorption, and mechanical properties. The utilization of SOM imaging revealed that the dispersion of chitosan within the starch phase was homogeneous when the chitosan content was below 9%. The study findings indicated that the incorporation of chitosan into thermoplastic chitosan/starch material resulted in a decrease in moisture absorption under varying humidity conditions (52%, 75%, and 85% RH). The results indicated that the material's hidden absorption is comparable in both environments, with a saturated moisture absorption range of 19%–25%. However, the material exhibited a significantly higher level of humidification at RH 85%, with an interaction range of 40%–48%. Furthermore, the findings suggested that an increase in chitosan content was positively correlated with an increase in tensile strength while negatively correlated with elongation at break.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140365802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nguyen Van Chien, Ta Thuy Nguyen, Dao Hai Yen, Hoang Thi Phuong, Phan Van Chuong, Nguyen Mai Phong
Slag is produced in large quantities during the manufacturing of yellow phosphorus in the Tang Loong Industrial Zone (Lao Cai province, Vietnam). It is required to clean them before using them as building materials. The research findings on cleaning yellow phosphorus slag in water with slaked lime or quicklime as aiding agents are presented in this article. According to experimental findings, the typical water consumption is between 4 and 6 m3 per ton of slag, or 160 g of 20% Ca(OH)2 or 25 g of CaO per 300 L of water. It is simple to reuse the water after rinsing the slag. The processed yellow phosphorus slag's elemental composition data reveal that Ca(SiO2)O, which has a pseudo‐wollastonite structure, is the product's primary constituent. Although P and F are still present, they are mainly in the stable glass phase of Ca(SiO2)O, and there are not many impurities. The treated yellow phosphorus slag can be used in large quantities for building materials due to its safe radioactivity index (I) < 1.
{"title":"Study on the processing technology to clean Lao Cai's yellow phosphorus slag for building materials","authors":"Nguyen Van Chien, Ta Thuy Nguyen, Dao Hai Yen, Hoang Thi Phuong, Phan Van Chuong, Nguyen Mai Phong","doi":"10.1002/vjch.202300291","DOIUrl":"https://doi.org/10.1002/vjch.202300291","url":null,"abstract":"Slag is produced in large quantities during the manufacturing of yellow phosphorus in the Tang Loong Industrial Zone (Lao Cai province, Vietnam). It is required to clean them before using them as building materials. The research findings on cleaning yellow phosphorus slag in water with slaked lime or quicklime as aiding agents are presented in this article. According to experimental findings, the typical water consumption is between 4 and 6 m3 per ton of slag, or 160 g of 20% Ca(OH)2 or 25 g of CaO per 300 L of water. It is simple to reuse the water after rinsing the slag. The processed yellow phosphorus slag's elemental composition data reveal that Ca(SiO2)O, which has a pseudo‐wollastonite structure, is the product's primary constituent. Although P and F are still present, they are mainly in the stable glass phase of Ca(SiO2)O, and there are not many impurities. The treated yellow phosphorus slag can be used in large quantities for building materials due to its safe radioactivity index (I) < 1.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140368339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ngo Van Quang, Nguyen Thi Mai Phuong, D. V. Luong, Do Thi Thanh Xuan, Phan Van Kiem, Nguyen Thi Trang Huyen, Thanh Thi Thu Thuy
Phytochemical study of Decaschistia harmandii led to the identification of four compounds (−)‐Ampelopsin F (1), Ampelopsin (2), Rhodomyrtone (3), and Phloretin (4). The chemical structures of the compounds were determined based on NMR spectra. Absolute configuration of (−)‐Ampelopsin F (1) was elucidated based on ECD spectra. Simultaneously, the cytotoxic activity of the compounds was tested on four human cancer cell lines (MCF7, 5637, HEPG2, and A549). Compounds 1 and 2 exhibited cytotoxic activity against all the tested cell lines, in which compound 1 showed strongest activity with IC50 value of 15.20 ± 0.16 µm followed by compound 2 with IC50 of 17.20 ± 0.02 µm for MCF7 and 5637 cells, respectively. In contrast, the other two compounds showed no activity. This is the first study on the chemical composition of the D. harmandii species.
{"title":"Structure, absolute configuration and cytotoxicity of compounds isolated from Decaschistia harmandii","authors":"Ngo Van Quang, Nguyen Thi Mai Phuong, D. V. Luong, Do Thi Thanh Xuan, Phan Van Kiem, Nguyen Thi Trang Huyen, Thanh Thi Thu Thuy","doi":"10.1002/vjch.202300170","DOIUrl":"https://doi.org/10.1002/vjch.202300170","url":null,"abstract":"Phytochemical study of Decaschistia harmandii led to the identification of four compounds (−)‐Ampelopsin F (1), Ampelopsin (2), Rhodomyrtone (3), and Phloretin (4). The chemical structures of the compounds were determined based on NMR spectra. Absolute configuration of (−)‐Ampelopsin F (1) was elucidated based on ECD spectra. Simultaneously, the cytotoxic activity of the compounds was tested on four human cancer cell lines (MCF7, 5637, HEPG2, and A549). Compounds 1 and 2 exhibited cytotoxic activity against all the tested cell lines, in which compound 1 showed strongest activity with IC50 value of 15.20 ± 0.16 µm followed by compound 2 with IC50 of 17.20 ± 0.02 µm for MCF7 and 5637 cells, respectively. In contrast, the other two compounds showed no activity. This is the first study on the chemical composition of the D. harmandii species.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dao Hai Yen, Hoang Thi Phuong, Nguyen Van Chien, Doan Ha Phuong, Ta Thuy Nguyen
The study's objective was to evaluate the role of epoxidized vegetable oils (EVOs) in the properties of polylactic acid (PLA) and PLA/cellulose composite materials. This study selects EVOs derived from commonly used vegetable oils in Vietnam, namely soybean oil, Cleidiocarpon cavaleriei oil, and linseed oil, as potential plasticizer agents for PLA. In this study, PLA and composite samples will be prepared using the melting method on a co‐rotating twin‐screw extruder. The evaluation of plastic efficiency in PLA is carried out through the XRD, physical properties, and differential scanning calorimetry analysis (DSC). The results show that the effective usage of EVOs agent was demonstrated by a decrease in PLA's Tg values. In particular, the Tg values of PLA‐ESBO, PLA‐ELO, and PLA‐ECCO were 54.8 °C, 52.3 °C, and 51.4 °C, respectively, as compared to the Tg value of PLA at 58.8 °C. In the XRD spectrum, the EVOs change the crystallization structure of PLA. Specifically, the intensity peak at 2θ ≈ 14.6° is markedly reduced in the EVO‐containing sample, while a distinct and intense peak disturbance emerges at 2θ ≈ 16.6°. The utilization of EVOs has been observed to impact the mechanical characteristics of PLA, resulting in a decrease in the tensile strength and an increase in the elongation at break.
{"title":"Study on plasticizing PLA using natural plasticizers available in Vietnam as a matrix resin for biodegradable PLA/cellulose composites","authors":"Dao Hai Yen, Hoang Thi Phuong, Nguyen Van Chien, Doan Ha Phuong, Ta Thuy Nguyen","doi":"10.1002/vjch.202300292","DOIUrl":"https://doi.org/10.1002/vjch.202300292","url":null,"abstract":"The study's objective was to evaluate the role of epoxidized vegetable oils (EVOs) in the properties of polylactic acid (PLA) and PLA/cellulose composite materials. This study selects EVOs derived from commonly used vegetable oils in Vietnam, namely soybean oil, Cleidiocarpon cavaleriei oil, and linseed oil, as potential plasticizer agents for PLA. In this study, PLA and composite samples will be prepared using the melting method on a co‐rotating twin‐screw extruder. The evaluation of plastic efficiency in PLA is carried out through the XRD, physical properties, and differential scanning calorimetry analysis (DSC). The results show that the effective usage of EVOs agent was demonstrated by a decrease in PLA's Tg values. In particular, the Tg values of PLA‐ESBO, PLA‐ELO, and PLA‐ECCO were 54.8 °C, 52.3 °C, and 51.4 °C, respectively, as compared to the Tg value of PLA at 58.8 °C. In the XRD spectrum, the EVOs change the crystallization structure of PLA. Specifically, the intensity peak at 2θ ≈ 14.6° is markedly reduced in the EVO‐containing sample, while a distinct and intense peak disturbance emerges at 2θ ≈ 16.6°. The utilization of EVOs has been observed to impact the mechanical characteristics of PLA, resulting in a decrease in the tensile strength and an increase in the elongation at break.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Phuong Hong Le, Kien Trung Nguyen, Oanh Kieu Thi Pham, V. Nguyen
Coffee pulp, the major by‐product of the beverage industry, is considered as an environmental threat, but also possesses high amounts of bioactive compounds. The extraction of these compounds by using conventional methods and solvents usually accompanies impurities. Here, an aqueous two‐phase system (ATPS) was optimized to extract and purify polyphenols from coffee pulp. Key affecting factors include phase system composition (ethanol and ammonium sulfate), extraction time and temperature while the quality of product was evaluated based on total phenolic content (TPC) and antioxidant activity (AA). The final optimized conditions were at 50 °C for 60 min using the ATPS of ethanol 37.7% (w/w) and ammonium sulfate 25% (w/w). TPC and AA at the optimal conditions were 434.63 ± 25.40 mg GAE/g dw and 622.71 ± 9.65 mg TE/g dw, respectively, which were higher than the results of the extract only used ethanol as the extraction solvent. The results showed that ATPS was a valuable method to extract and purify coffee bioactive compounds.
{"title":"Extracting and purifying polyphenols from coffee pulp (Coffee arabica L.) using aqueous two‐phase systems","authors":"Phuong Hong Le, Kien Trung Nguyen, Oanh Kieu Thi Pham, V. Nguyen","doi":"10.1002/vjch.202300228","DOIUrl":"https://doi.org/10.1002/vjch.202300228","url":null,"abstract":"Coffee pulp, the major by‐product of the beverage industry, is considered as an environmental threat, but also possesses high amounts of bioactive compounds. The extraction of these compounds by using conventional methods and solvents usually accompanies impurities. Here, an aqueous two‐phase system (ATPS) was optimized to extract and purify polyphenols from coffee pulp. Key affecting factors include phase system composition (ethanol and ammonium sulfate), extraction time and temperature while the quality of product was evaluated based on total phenolic content (TPC) and antioxidant activity (AA). The final optimized conditions were at 50 °C for 60 min using the ATPS of ethanol 37.7% (w/w) and ammonium sulfate 25% (w/w). TPC and AA at the optimal conditions were 434.63 ± 25.40 mg GAE/g dw and 622.71 ± 9.65 mg TE/g dw, respectively, which were higher than the results of the extract only used ethanol as the extraction solvent. The results showed that ATPS was a valuable method to extract and purify coffee bioactive compounds.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140366918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mayank Tiwari, Rajesh K. Yadav, Satyam Singh, Pooja Singh, Rehana Shahin, Omvir Singh, N. K. Gupta, Suresh K. Pandey, D. Tiwary, Jin‐Ook Baeg
The solar light responsive selective C(sp3)─H bond activation by photocatalytic pathway using graphene platform as photocatalyst is a green and sustainable route to achieve value‐added chemicals on gram scale synthesis. Graphene has low activity due to fast recombination charges, band gap suitability problems, and inefficient solar light absorption ability. Therefore, activated carbon cloth‐based nitrogen‐rich phenolic resin was developed from melem and formaldehyde. The ACC@MeF light‐harvesting composite demonstrates outstanding light‐harvesting capability, leading to enhanced photocatalytic performance in C(sp3)─H bond formation, suitability of band gap, high molar extinction coefficient and high thermal stability. The development of metal‐free activated carbon cloth‐based melem formaldehyde resin for the solar light photocatalytic transformation of organic compounds is anticipated to have broad‐reaching applications.
{"title":"Sunlight sparks spectacular C(sp3)─H bond arylation: Rod shape ACC@MeF composite shines bright in 2,4‐dinitrophenylhydrazine reaction","authors":"Mayank Tiwari, Rajesh K. Yadav, Satyam Singh, Pooja Singh, Rehana Shahin, Omvir Singh, N. K. Gupta, Suresh K. Pandey, D. Tiwary, Jin‐Ook Baeg","doi":"10.1002/vjch.202300215","DOIUrl":"https://doi.org/10.1002/vjch.202300215","url":null,"abstract":"The solar light responsive selective C(sp3)─H bond activation by photocatalytic pathway using graphene platform as photocatalyst is a green and sustainable route to achieve value‐added chemicals on gram scale synthesis. Graphene has low activity due to fast recombination charges, band gap suitability problems, and inefficient solar light absorption ability. Therefore, activated carbon cloth‐based nitrogen‐rich phenolic resin was developed from melem and formaldehyde. The ACC@MeF light‐harvesting composite demonstrates outstanding light‐harvesting capability, leading to enhanced photocatalytic performance in C(sp3)─H bond formation, suitability of band gap, high molar extinction coefficient and high thermal stability. The development of metal‐free activated carbon cloth‐based melem formaldehyde resin for the solar light photocatalytic transformation of organic compounds is anticipated to have broad‐reaching applications.","PeriodicalId":23525,"journal":{"name":"Vietnam Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140367967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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