A novel surface modification technique for graphite films (GF) to improve the interface thermal resistance with epoxy resin was presented. By utilizing the self-polymerization of dopamine (PDA), dopamine micro and nanoparticles were formed on the surface of the GF. Subsequently, the surface of the epoxy resin was functionalized with polydopamine (PDA) through grafting of the silane coupling agent 3-glycidyl ether oxy-propyl trimethoxy silane (GOPTS), enabling the introduction of epoxy resin groups onto the surface of the GF. Employing a simple folding technique, a three-dimensional GF network (3DGF) was constructed, in which modified GF was successfully incorporated into the polymer matrix. The results showed that the 3DGF network further promoted the effective transfer of heat and electrons within the composite, leading to a significant improvement in thermal and electrothermal conversion performance. The prepared 3DGPGF/epoxy resin composite exhibits high thermal conductivity (7.14 W/mK) at a relatively low GF loading (31.9 wt%). Under a voltage of 12 V, the surface temperature of the sample rapidly rises from room temperature to 130°C within 200 s, and can completely melt ice cubes within 60 s. These results indicate that epoxy-silane-dopamine-modified graphite film can be a promising candidate material, and this work provides a promising strategy for designing and manufacturing high-performance composites with improved thermal properties. The developed method has the potential to be extended to other polymer matrices and fillers, and the prepared composites have enormous potential in various applications.
{"title":"Enhanced thermal conductivity and electrothermal conversion of epoxy composites through silane-dopamine modified graphite films","authors":"Wen Li, Lingcheng Kong, Wei Zhang, Dong Zhao, Wenbo Xin","doi":"10.1002/app.56186","DOIUrl":"10.1002/app.56186","url":null,"abstract":"<p>A novel surface modification technique for graphite films (GF) to improve the interface thermal resistance with epoxy resin was presented. By utilizing the self-polymerization of dopamine (PDA), dopamine micro and nanoparticles were formed on the surface of the GF. Subsequently, the surface of the epoxy resin was functionalized with polydopamine (PDA) through grafting of the silane coupling agent 3-glycidyl ether oxy-propyl trimethoxy silane (GOPTS), enabling the introduction of epoxy resin groups onto the surface of the GF. Employing a simple folding technique, a three-dimensional GF network (3DGF) was constructed, in which modified GF was successfully incorporated into the polymer matrix. The results showed that the 3DGF network further promoted the effective transfer of heat and electrons within the composite, leading to a significant improvement in thermal and electrothermal conversion performance. The prepared 3DGPGF/epoxy resin composite exhibits high thermal conductivity (7.14 W/mK) at a relatively low GF loading (31.9 wt%). Under a voltage of 12 V, the surface temperature of the sample rapidly rises from room temperature to 130°C within 200 s, and can completely melt ice cubes within 60 s. These results indicate that epoxy-silane-dopamine-modified graphite film can be a promising candidate material, and this work provides a promising strategy for designing and manufacturing high-performance composites with improved thermal properties. The developed method has the potential to be extended to other polymer matrices and fillers, and the prepared composites have enormous potential in various applications.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 44","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A copolymer based on styrene and 1-hexene was synthesized using free-radical emulsion polymerization. Reaction pressure has a significant influence on copolymer formation. There was a phase separation when styrene was copolymerized with 1-hexene at lower pressure (1 bar) and a stable emulsion was observed under a pressurized reaction (4.5 bar). Additionally, a phase separation was also observed at a lower reaction pH (7.2) and was evidenced by the reduced pH value at the end of the copolymerization. H1 nuclear magnetic resonance (NMR) spectroscopy analysis showed the disappearance of methylene proton peak intensities in both styrene and 1-hexene after the copolymerization reaction indicating the increased conversion of monomers in emulsion. Synthesized copolymer was also studied using the C13 NMR analysis. It was further analyzed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The emulsion was destabilized by the synergistic action of acid and temperature to recover solid polymer. The applicability of the copolymer as a polymer modifier was studied by blending with commercial PS. Copolymer thermal properties were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Other properties such as emulsion particle size, droplet morphology, and the effect of pH were also investigated in this study.
{"title":"Free-radical emulsion copolymerization of styrene/1-hexene in an autoclave: Synthesis and property evaluation","authors":"Sanjay Remanan, Mamdouh Ahmed Al-Harthi","doi":"10.1002/app.56194","DOIUrl":"10.1002/app.56194","url":null,"abstract":"<p>A copolymer based on styrene and 1-hexene was synthesized using free-radical emulsion polymerization. Reaction pressure has a significant influence on copolymer formation. There was a phase separation when styrene was copolymerized with 1-hexene at lower pressure (1 bar) and a stable emulsion was observed under a pressurized reaction (4.5 bar). Additionally, a phase separation was also observed at a lower reaction pH (7.2) and was evidenced by the reduced pH value at the end of the copolymerization. H<sup>1</sup> nuclear magnetic resonance (NMR) spectroscopy analysis showed the disappearance of methylene proton peak intensities in both styrene and 1-hexene after the copolymerization reaction indicating the increased conversion of monomers in emulsion. Synthesized copolymer was also studied using the C<sup>13</sup> NMR analysis. It was further analyzed by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The emulsion was destabilized by the synergistic action of acid and temperature to recover solid polymer. The applicability of the copolymer as a polymer modifier was studied by blending with commercial PS. Copolymer thermal properties were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Other properties such as emulsion particle size, droplet morphology, and the effect of pH were also investigated in this study.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 45","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinlin Man, Xinyue Guan, Guanshao Huang, Junjie Zhou, Han Miao, Xinxin Li
The development of effective dispersants for nanoparticle suspensions is crucial for enhancing the performance and stability of various functional materials. In this study, we investigated a series of comb-like block copolymers with well-defined structures, including both categories of block copolymers and uniformly composed random copolymers, as dispersants for cerium oxide (CeO2) suspensions. Acrylic acid (AA) units were used for anchoring and electrostatic repulsion, while methoxy polyethylene glycol acrylate (MPEGA) units provided additional steric hindrance and solubility. We explored stabilization mechanisms involving polymer topologies, chain lengths, compositions, and molecular interactions from kinetic and thermodynamic perspectives. The results demonstrate significant improvements in dispersion stability with both categories of well-controlled copolymers, especially with uniformly composed random copolymers due to their uniformly distributed multi-point anchoring and balanced electrostatic and steric stabilization. This research not only enhances the fundamental understanding of polymer-nanoparticle interactions and polymer dispersants, but also provides valuable guidance for the tailored design of dispersants for specific industrial and scientific needs.
{"title":"Tailored design of well-defined comb-like copolymer dispersants for enhanced dispersion and stability of cerium oxide nanoparticle suspensions","authors":"Jinlin Man, Xinyue Guan, Guanshao Huang, Junjie Zhou, Han Miao, Xinxin Li","doi":"10.1002/app.56243","DOIUrl":"10.1002/app.56243","url":null,"abstract":"<p>The development of effective dispersants for nanoparticle suspensions is crucial for enhancing the performance and stability of various functional materials. In this study, we investigated a series of comb-like block copolymers with well-defined structures, including both categories of block copolymers and uniformly composed random copolymers, as dispersants for cerium oxide (CeO<sub>2</sub>) suspensions. Acrylic acid (AA) units were used for anchoring and electrostatic repulsion, while methoxy polyethylene glycol acrylate (MPEGA) units provided additional steric hindrance and solubility. We explored stabilization mechanisms involving polymer topologies, chain lengths, compositions, and molecular interactions from kinetic and thermodynamic perspectives. The results demonstrate significant improvements in dispersion stability with both categories of well-controlled copolymers, especially with uniformly composed random copolymers due to their uniformly distributed multi-point anchoring and balanced electrostatic and steric stabilization. This research not only enhances the fundamental understanding of polymer-nanoparticle interactions and polymer dispersants, but also provides valuable guidance for the tailored design of dispersants for specific industrial and scientific needs.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 46","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ananda K. C. Albuquerque, Pedro H. M. Nicácio, Laura Boskamp, Katharina Arnaut, Katharina Koschek, Renate Maria Ramos Wellen
Renewable resources based polymers have been the focus of materials science scientists since they help to protect the environment in addition to reducing the petroleum resources use. Among renewable polymers poly (lactic acid) (PLA) has emerged due to its biodegradable character and proper performance similar to engineering resins, which afford wide field of applications. In this work the thermal degradation of esterified PLA with itaconic acid (PLA ITA) and the biocomposite PLA ITA FLAX was investigated using thermogavimetry (TG) which data were corroborated through Fourier transform infrared spectroscopy (FTIR). Isothermal TGs scans and FTIRs spectra were acquired from 150 to 600°C, collected data evidenced that FLAX improved PLA ITA thermal stability, delaying the decomposition of PLA ITA by up to 100 min at 250°C, ensuring safer processability at higher temperatures. From the deconvolution of the DTG peaks, the peak at lower temperature is suggested to be linked to itaconic anhydride decomposition which undergoes macromolecule dissociation, converting into itaconic anhydride and releasing water and afterwards being converted into citraconic anhydride, while the peak at higher temperature is associated to the thermal degradation of telechelic PLA. Degradation mechanism is proposed, evidenced by changes in the wavelength of CO group under the effect of temperature, as evidenced in TG-IR spectra.
基于可再生资源的聚合物一直是材料科学科学家关注的焦点,因为它们不仅有助于保护环境,还能减少石油资源的使用。在可再生聚合物中,聚乳酸(PLA)因其可生物降解的特性和类似工程树脂的适当性能而崭露头角,应用领域十分广泛。在这项研究中,使用热重仪(TG)研究了衣康酸酯化聚乳酸(PLA ITA)和生物复合材料 PLA ITA FLAX 的热降解,并通过傅立叶变换红外光谱(FTIR)对数据进行了证实。从 150 到 600°C 的等温 TG 扫描和傅立叶变换红外光谱采集的数据表明,FLAX 提高了聚乳酸 ITA 的热稳定性,在 250°C 下可将聚乳酸 ITA 的分解时间延迟 100 分钟,从而确保了在更高温度下的加工安全性。从 DTG 峰的解卷积来看,较低温度下的峰与衣康酸酐分解有关,衣康酸酐分解时会发生大分子解离,转化为衣康酸酐并释放出水,然后转化为柠檬康酸酐;而较高温度下的峰与远志聚乳酸的热降解有关。根据 TG-IR 光谱显示的 CO 基团波长在温度作用下的变化,提出了降解机制。
{"title":"On the thermal degradation of telechelic poly (lactic acid) and FLAX fiber biocomposites","authors":"Ananda K. C. Albuquerque, Pedro H. M. Nicácio, Laura Boskamp, Katharina Arnaut, Katharina Koschek, Renate Maria Ramos Wellen","doi":"10.1002/app.56217","DOIUrl":"10.1002/app.56217","url":null,"abstract":"<p>Renewable resources based polymers have been the focus of materials science scientists since they help to protect the environment in addition to reducing the petroleum resources use. Among renewable polymers poly (lactic acid) (PLA) has emerged due to its biodegradable character and proper performance similar to engineering resins, which afford wide field of applications. In this work the thermal degradation of esterified PLA with itaconic acid (PLA ITA) and the biocomposite PLA ITA FLAX was investigated using thermogavimetry (TG) which data were corroborated through Fourier transform infrared spectroscopy (FTIR). Isothermal TGs scans and FTIRs spectra were acquired from 150 to 600°C, collected data evidenced that FLAX improved PLA ITA thermal stability, delaying the decomposition of PLA ITA by up to 100 min at 250°C, ensuring safer processability at higher temperatures. From the deconvolution of the DTG peaks, the peak at lower temperature is suggested to be linked to itaconic anhydride decomposition which undergoes macromolecule dissociation, converting into itaconic anhydride and releasing water and afterwards being converted into citraconic anhydride, while the peak at higher temperature is associated to the thermal degradation of telechelic PLA. Degradation mechanism is proposed, evidenced by changes in the wavelength of CO group under the effect of temperature, as evidenced in TG-IR spectra.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 45","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Samira Maou, Yazid Meftah, Yves Grohens, Antoine Kervoelen, Anthony Magueresse, Wassila Selmani, Fatima Ferhad
Lignocellulosic fiber-reinforced composites exhibit enhanced physical properties and eco-friendliness, which has resulted in extended application of these biocomposite materials in important engineering sectors. In this study, we investigated the synergistic impacts of dune sand (DS)-based silica (SiO2) and alkali-treated date palm fiber (ADPF) fillers on the thermophysical and viscoelastic characteristics of epoxy (EP) hybrid composites. A hand layup procedure was employed to produce EP hybrid composites reinforced with 20 wt.% ADPF as well as 5, 7, and 10 wt.% DS. Compared to the other composite samples, the EP matrix reinforced with 20 wt.% ADPF and 10 wt.% DS (HC5) exhibited better thermal (Tmax = 380°C, Tg = 63.13°C) and dynamic mechanical properties (storage modulus = 2700 MPa). Additionally, Cole–Cole plots revealed the excellent interaction between ADPF, DS, and epoxy matrix. Scanning electron microscopy (SEM) measurements further confirmed that the development of an effective interface between DS particles, ADPF fiber, and epoxy matrix caused a decrease in water absorption (1.5%). The best wetting conditions with the lowest thickness swelling (2.8%) were obtained by increasing the DS content up to 10 wt.%. Based on these findings, it can be concluded that, owing to their superior dynamic mechanical characteristics, hybrid composites containing 10 wt.% DS may be employed in important aircraft and aeronautic applications.
{"title":"Synergistic effects of dune sand-based silica and alkali-treated date palm fiber as efficient fillers for improving the properties of hybrid epoxy composites","authors":"Samira Maou, Yazid Meftah, Yves Grohens, Antoine Kervoelen, Anthony Magueresse, Wassila Selmani, Fatima Ferhad","doi":"10.1002/app.56238","DOIUrl":"10.1002/app.56238","url":null,"abstract":"<p>Lignocellulosic fiber-reinforced composites exhibit enhanced physical properties and eco-friendliness, which has resulted in extended application of these biocomposite materials in important engineering sectors. In this study, we investigated the synergistic impacts of dune sand (DS)-based silica (SiO<sub>2</sub>) and alkali-treated date palm fiber (ADPF) fillers on the thermophysical and viscoelastic characteristics of epoxy (EP) hybrid composites. A hand layup procedure was employed to produce EP hybrid composites reinforced with 20 wt.% ADPF as well as 5, 7, and 10 wt.% DS. Compared to the other composite samples, the EP matrix reinforced with 20 wt.% ADPF and 10 wt.% DS (HC5) exhibited better thermal (<i>T</i><sub>max</sub> = 380°C, <i>T</i><sub>g</sub> = 63.13°C) and dynamic mechanical properties (storage modulus = 2700 MPa). Additionally, Cole–Cole plots revealed the excellent interaction between ADPF, DS, and epoxy matrix. Scanning electron microscopy (SEM) measurements further confirmed that the development of an effective interface between DS particles, ADPF fiber, and epoxy matrix caused a decrease in water absorption (1.5%). The best wetting conditions with the lowest thickness swelling (2.8%) were obtained by increasing the DS content up to 10 wt.%. Based on these findings, it can be concluded that, owing to their superior dynamic mechanical characteristics, hybrid composites containing 10 wt.% DS may be employed in important aircraft and aeronautic applications.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 46","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a novel biodegradable coir fiber (CF) reinforced thermoplastic starch (TPS) and poly(butylene adipate-co-terephthalate) (PBAT) composites (CF/TPS/PBAT) with a constant TPS: PBAT weight ratio of 70:30 and 5, 10, 15, and 20 wt% additions of CF were prepared by the melt blending and injection molding. The effects of fiber content and fiber surface modification on the mechanical and thermal properties of the prepared biocomposites were investigated. The incorporation of fibers effectively enhanced the mechanical and thermal properties of TPS/PBAT blends. Due to the removal of hemicellulose and impurities on the fiber surface after alkali treatment, the interfacial adhesion of the fiber was enhanced, thus improving the compatibility between the fibers and the matrix. At 20 wt% CFs with alkali treatment, the tensile strength exhibited 393% improvement and flexural strength exhibited 536% improvement over TPS/PBAT blends. Thermal analysis showed that the thermal stability, storage modulus, and glass transition temperature of the composites increased with the increase of fiber content. This work is significant for the development of biodegradable materials.
{"title":"Study on mechanical and thermal properties of coir fibers reinforced thermoplastic starch/poly(butylene adipate-co-terephthalate) composites","authors":"Xianggang Tang, Jianwei Tan, Yongxiang Hu, Chengzhuang Su, Zhekun Liu, Chuncheng Wei, Shuhua Dong, Fantao Meng","doi":"10.1002/app.56206","DOIUrl":"10.1002/app.56206","url":null,"abstract":"<p>In this study, a novel biodegradable coir fiber (CF) reinforced thermoplastic starch (TPS) and poly(butylene adipate-<i>co</i>-terephthalate) (PBAT) composites (CF/TPS/PBAT) with a constant TPS: PBAT weight ratio of 70:30 and 5, 10, 15, and 20 wt% additions of CF were prepared by the melt blending and injection molding. The effects of fiber content and fiber surface modification on the mechanical and thermal properties of the prepared biocomposites were investigated. The incorporation of fibers effectively enhanced the mechanical and thermal properties of TPS/PBAT blends. Due to the removal of hemicellulose and impurities on the fiber surface after alkali treatment, the interfacial adhesion of the fiber was enhanced, thus improving the compatibility between the fibers and the matrix. At 20 wt% CFs with alkali treatment, the tensile strength exhibited 393% improvement and flexural strength exhibited 536% improvement over TPS/PBAT blends. Thermal analysis showed that the thermal stability, storage modulus, and glass transition temperature of the composites increased with the increase of fiber content. This work is significant for the development of biodegradable materials.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 45","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sang-Hun Choi, Soo-Hyang Chi, Yu-Seong Park, Sejin Son, Young-Eun Cho, Jihoon Kim
Ulcerative colitis (UC) is a chronic, recurring inflammatory condition triggered by immunological imbalances in the digestive tract, leading to weight loss, diarrhea, rectal bleeding, and an increased risk of colon cancer. Existing UC treatments encounter significant limitations, such as primary non-responsiveness, secondary loss of efficacy, and adverse effects. This necessitates the development of drugs and drug formulations to broaden UC treatment options. This study describes the extended retention of poly(maleic anhydride)-drug conjugates in the large intestine of a DSS-induced acute colitis mouse model and highlights their potential for treating UC. Anti-inflammatory sirolimus (Siro) is considered an alternative drug for UC treatment, which however also has side effects due to nonspecific systemic delivery. Accordingly, poly(malic anhydride)-sirolimus (pSiro) is synthesized by linking Siro, a representative immunosuppressant and anti-inflammatory drug used in clinical practice, to anhydride groups of poly(maleic anhydride) via ester bonds. In a biodistribution study, poly(maleic anhydride) increases drug retention in the large intestine. Histochemical staining reveals the reduced inflammation degree in the treatment of pSiro, which leads to the decline of systemic inflammatory markers such as plasma TNF-α, NO, and LPS levels. These results suggest pSiro as a potential therapeutic option for the treatment of UC.
{"title":"Colon-adhesive poly(maleic anhydride)-sirolimus conjugate alleviates local colitis inflammation","authors":"Sang-Hun Choi, Soo-Hyang Chi, Yu-Seong Park, Sejin Son, Young-Eun Cho, Jihoon Kim","doi":"10.1002/app.56220","DOIUrl":"10.1002/app.56220","url":null,"abstract":"<p>Ulcerative colitis (UC) is a chronic, recurring inflammatory condition triggered by immunological imbalances in the digestive tract, leading to weight loss, diarrhea, rectal bleeding, and an increased risk of colon cancer. Existing UC treatments encounter significant limitations, such as primary non-responsiveness, secondary loss of efficacy, and adverse effects. This necessitates the development of drugs and drug formulations to broaden UC treatment options. This study describes the extended retention of poly(maleic anhydride)-drug conjugates in the large intestine of a DSS-induced acute colitis mouse model and highlights their potential for treating UC. Anti-inflammatory sirolimus (Siro) is considered an alternative drug for UC treatment, which however also has side effects due to nonspecific systemic delivery. Accordingly, poly(malic anhydride)-sirolimus (pSiro) is synthesized by linking Siro, a representative immunosuppressant and anti-inflammatory drug used in clinical practice, to anhydride groups of poly(maleic anhydride) via ester bonds. In a biodistribution study, poly(maleic anhydride) increases drug retention in the large intestine. Histochemical staining reveals the reduced inflammation degree in the treatment of pSiro, which leads to the decline of systemic inflammatory markers such as plasma TNF-<i>α</i>, NO, and LPS levels. These results suggest pSiro as a potential therapeutic option for the treatment of UC.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 45","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Six varieties of alkoxy polyhedral oligomeric silsesquioxanes (POSSs) featuring methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, and n-hexoxy as terminal groups were synthesized using the direct dehydrogenation condensation method. These POSSs were then incorporated as cross-linking agents into hydroxy-terminated polydimethylsiloxane (HPDMS) to create various formulations of room temperature vulcanized silicone rubbers (RTV SRs), denoted as SRM, SRE, SRP, SRI, SRB, and SRH. The morphology, thermal stability, and mechanical properties of the resulting SRs are analyzed using scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and universal tensile testing machine. The findings indicate that the incorporation of POSS into SRs results in significant enhancements in thermal stability and mechanical properties when compared to the control group (TEOS/SR). SRB and SRH exhibit the highest cross-linking density and tensile strength. Specifically, SRB-4 demonstrates the highest tensile strength at 2.66 MPa, representing an 8.6-fold increase compared to TEOS/SR. The maximum decomposition rate temperature of SRP-4 reaches 527°C and is 194°C higher than TEOS/SR. Because the alkoxy groups with different chain lengths on POSS have different chemical reactivity, they have a great effect on the dispersion of POSS in SRs, which affect the cross-linking density, tensile strength, and thermal stability.
{"title":"Effect of different alkoxy POSSs on thermal stability and mechanical properties of silicone rubber","authors":"Song Yang, Xiaoyu Chen, Peng Xu, Jianjun Shi, Qi Yao, Junning Li, Ziping Zhou, Guangxin Chen, Qifang Li, Zheng Zhou","doi":"10.1002/app.56104","DOIUrl":"10.1002/app.56104","url":null,"abstract":"<p>Six varieties of alkoxy polyhedral oligomeric silsesquioxanes (POSSs) featuring methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, and n-hexoxy as terminal groups were synthesized using the direct dehydrogenation condensation method. These POSSs were then incorporated as cross-linking agents into hydroxy-terminated polydimethylsiloxane (HPDMS) to create various formulations of room temperature vulcanized silicone rubbers (RTV SRs), denoted as SRM, SRE, SRP, SRI, SRB, and SRH. The morphology, thermal stability, and mechanical properties of the resulting SRs are analyzed using scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and universal tensile testing machine. The findings indicate that the incorporation of POSS into SRs results in significant enhancements in thermal stability and mechanical properties when compared to the control group (TEOS/SR). SRB and SRH exhibit the highest cross-linking density and tensile strength. Specifically, SRB-4 demonstrates the highest tensile strength at 2.66 MPa, representing an 8.6-fold increase compared to TEOS/SR. The maximum decomposition rate temperature of SRP-4 reaches 527°C and is 194°C higher than TEOS/SR. Because the alkoxy groups with different chain lengths on POSS have different chemical reactivity, they have a great effect on the dispersion of POSS in SRs, which affect the cross-linking density, tensile strength, and thermal stability.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 42","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Near-infrared laser-activated gold nanorods (AuNRs) with excellent photothermal property and tunable surface functionalization are considered as an ideal platform for biomedical applications. However, bare AuNRs have cytotoxicity against normal cells and are prone to agglomeration during laser irradiation. Herein, multivalent polymer-functionalized AuNRs (AuNRs@pDMAEMA-C4) was constructed as a highly stable and biocompatible photothermal agent for enhanced antibacterial therapy. The functionalized polymer was synthetized via the reversible addition-fragmentation chain transfer polymerization and subsequently quaternized. Moreover, positively charged AuNRs@pDMAEMA-C4 can easily capture the bacterial surface via electrostatic interactions. The integration of photothermal therapy of AuNRs and chemotherapy of functionalized polymer can achieve enhanced antibacterial effects. Under 808 nm laser irradiation, AuNRs@pDMAEMA-C4 possessed excellent photothermal conversion capability and can kill gram-positive and gram-negative bacteria. Study of the antibacterial mechanism indicated that the antibacterial action of the prepared photothermal antibacterial agent can cause serious damage of the bacterial outer membranes, result in cytoplasm leakage and bacterial death. The nanocomposites combining with near-infrared laser irradiation can facilitate rapid healing of bacteria-infected wound by rat model of wound infection and histological analysis of the wound tissues. These results suggest that the surface functionalization can be used as potential strategy to fabricate light-activated therapeutic agent for biomedical applications.
{"title":"Stable and biocompatible multivalent polymer-grafted gold nanorods for enhanced photothermal antibacterial therapy","authors":"Lin Mei, Zhimin Liu, Yanmei Shi, Xiangyun Zhang","doi":"10.1002/app.56230","DOIUrl":"10.1002/app.56230","url":null,"abstract":"<p>Near-infrared laser-activated gold nanorods (AuNRs) with excellent photothermal property and tunable surface functionalization are considered as an ideal platform for biomedical applications. However, bare AuNRs have cytotoxicity against normal cells and are prone to agglomeration during laser irradiation. Herein, multivalent polymer-functionalized AuNRs (AuNRs@pDMAEMA-C<sub>4</sub>) was constructed as a highly stable and biocompatible photothermal agent for enhanced antibacterial therapy. The functionalized polymer was synthetized via the reversible addition-fragmentation chain transfer polymerization and subsequently quaternized. Moreover, positively charged AuNRs@pDMAEMA-C<sub>4</sub> can easily capture the bacterial surface via electrostatic interactions. The integration of photothermal therapy of AuNRs and chemotherapy of functionalized polymer can achieve enhanced antibacterial effects. Under 808 nm laser irradiation, AuNRs@pDMAEMA-C<sub>4</sub> possessed excellent photothermal conversion capability and can kill gram-positive and gram-negative bacteria. Study of the antibacterial mechanism indicated that the antibacterial action of the prepared photothermal antibacterial agent can cause serious damage of the bacterial outer membranes, result in cytoplasm leakage and bacterial death. The nanocomposites combining with near-infrared laser irradiation can facilitate rapid healing of bacteria-infected wound by rat model of wound infection and histological analysis of the wound tissues. These results suggest that the surface functionalization can be used as potential strategy to fabricate light-activated therapeutic agent for biomedical applications.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 46","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing bio-based plasticizers not only aids in the reduction of fossil fuel consumption but also presents a lower risk to human health. In this study, a fully biodegradable plasticizer—levulinate malate ethanol lactates (LMEL) was successfully synthesized from L-lactic acid, DL-malic acid, levulinic acid, and ethanol, and was compared with commercially plasticizers (acetyl tributyl citrate (ATBC), dioctyl phthalate (DOP) and di-2-ethylhexyl terephthalate (DOTP)). 40 phr LMEL plasticized polyvinyl chloride (PVC) (40LMEL) yielded a remarkable elongation at break of 526.9%, compared with the pure PVC resin (4.5%), thereby significantly enhancing the flexibility of PVC. Moreover, the optical transparency of 40LMEL samples was found to be equivalent to PVC plasticized with three commercial plasticizers. Most importantly, compared with three commercial plasticizers, 40LMEL exhibited superior resistance to migration and volatility, with mass losses of 1.055% in H2O, 13.601% in n-hexane, 14.636% in ethanol, and 1.496% in activated carbon, respectively. Soil degradation experiments have demonstrated that LMEL can be broken down by microorganisms in the soil into nontoxic aliphatic compounds (e.g., 4-oxo-pentanoic acid, and 4,5,7-trihydroxy 2-octenoic acid, et al.). Collectively, LMEL exhibited better overall performance than three commercial plasticizers. This work provides new options for the design of efficient fully bio-based plasticizers.
{"title":"Synthesis, characterization, and performance evaluation of a high-efficiency fully biobased biodegradable plasticizer","authors":"Boyou Hou, Yinan Sun, Yanlin Guo, Wei Zhang, Xueying Shan, Qianqian Cui, Zhendong Chen, Qingting Ni, Jinchun Li","doi":"10.1002/app.56225","DOIUrl":"10.1002/app.56225","url":null,"abstract":"<p>Developing bio-based plasticizers not only aids in the reduction of fossil fuel consumption but also presents a lower risk to human health. In this study, a fully biodegradable plasticizer—levulinate malate ethanol lactates (LMEL) was successfully synthesized from L-lactic acid, DL-malic acid, levulinic acid, and ethanol, and was compared with commercially plasticizers (acetyl tributyl citrate (ATBC), dioctyl phthalate (DOP) and di-2-ethylhexyl terephthalate (DOTP)). 40 phr LMEL plasticized polyvinyl chloride (PVC) (40LMEL) yielded a remarkable elongation at break of 526.9%, compared with the pure PVC resin (4.5%), thereby significantly enhancing the flexibility of PVC. Moreover, the optical transparency of 40LMEL samples was found to be equivalent to PVC plasticized with three commercial plasticizers. Most importantly, compared with three commercial plasticizers, 40LMEL exhibited superior resistance to migration and volatility, with mass losses of 1.055% in H<sub>2</sub>O, 13.601% in n-hexane, 14.636% in ethanol, and 1.496% in activated carbon, respectively. Soil degradation experiments have demonstrated that LMEL can be broken down by microorganisms in the soil into nontoxic aliphatic compounds (e.g., 4-oxo-pentanoic acid, and 4,5,7-trihydroxy 2-octenoic acid, et al.). Collectively, LMEL exhibited better overall performance than three commercial plasticizers. This work provides new options for the design of efficient fully bio-based plasticizers.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 45","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}