HIGH PERFORMANCE POLYMERS
·
2020
·
IF 1.568
Zi-Long Wang,Xian-Yuan Liu,Yue Han,Ying Guo,Heng Zhou,Jun Wang,Wen-Bin Liu,Tong Zhao
In this article, a kind of polyester-type phthalonitrile cyano resin (2,2-bis (((3-((4-(3,4-dicyanophenoxy) benzoyl)oxy)-2-(hydroxymethyl)-2-methylpropanoyl)oxy)methyl) propane-1,3-diyl)bis(oxy)) bis (2-(hydroxymethyl)-2-methyl-3-oxopropane-3, 1-diyl) bis (4-(3,4-dicyanophenoxy) benzoate (hbppn)) with branched structure was introduced. The molecular structure and relative molecular mass of hbppn were characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF). The results showed that the synthesized HBPPN contained both polyester and hyperbranched structures. The thermal and rheological properties of HBPPN were characterized by differential scanning calorimetry and rheometer, and the results showed that HBPPN would be cured at about 322°C and the viscosity of the resin showed good processability. The results of dynamic mechanical analysis and thermogravimetric analysis showed that the synthesized resin had good heat resistance. The glass transition temperature was above 329°C, the residual weight (C y) at 900°C was as high as 66.2% in the nitrogen atmosphere, and the temperature at which the resin lost 5 wt% of heat in air atmosphere was about 423.3°C. The synthesized HBPPN had good comprehensive properties, which could be applied to high-temperature resistant and thermal protection materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2017
·Vol. 35
·期 11
·1428-1435
·
IF 1.692
Wei Xiao-yan,Zhao Bo-xuan,Shang Ya-zhuo,Cheng Yuan-rong
Biphenyl-contained monomer of 1,4-bis[2-(3,4-epoxy cyclohexyl ethyl) dimethylsilyl] biphenyl (BP-SiH-EP) was prepared via hydrosilylation reaction of 1,4-bis(dimethylsilyl) biphenyl (BP-SiH) and 1,2-epoxy-4-vinylcyclohexane in the presence of Karstedt’s catalyst. 1 H-NMR, 13 C-NMR and FTIR were used to characterize the structure of the obtained monomer. BP-SiH-EP was then cured by methyl hexahydrophthalic anhydride (MeHHPA) with 1-cyanoethyl-2-ethyl-4-methylimidazole as an accelerator. The polymerization behavior was studied by DSC. The results of DMA measurement demonstrate that the cured BP-SiH-EP/MeHHPA can maintain high storage modulus (> 1 GPa) in a wide range of temperature up to 176 °C. According to the damping factor curve of DMA, cured BP-SiH-EP/MeHHPA exhibits a high glass transition temperature ( T
g ) of 192 °C, which is 20 °C higher than that of cured 1,4-bis[2-(3,4-epoxy cyclohexyl ethyl) dimethylsilyl] benzene (DEDSB)/MeHHPA. TGA results show that cured BP-SiH-EP/MeHHPA has good thermal stability ( T
5% = 339 °C) due to the high heat-resistance of rigid biphenyl group. Moreover, the crosslinking density of cured BP-SiH-EP/MeHHPA should be lower than that of cured DEDSB/MeHHPA estimated from their chemical structures, which conflicts with the calculated results based on the rubber elasticity equation. The inconsistence indicates that the calculated crosslinking densities are not comparable, possibly owing to their differences in the rigidity of polymer chains and intermolecular interaction.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Small Methods
·
2023
·
IF 12.4
Xinxin Hang,Zhaocun Huang,Shiqi He,Zhiying Wang,Zaizai Dong,Lingqian Chang
In vitro, drug assessment holds tremendous potential to success in novel drug development and precision medicine. Traditional techniques for drug assessment, however, face remarkable challenges to achieve high speed, as limited by incubation-based drug delivery (>several hours) and cell viability measurements (>1 d), which significantly compromise the efficacy in clinical trials. In this work, a nano-electroporation-DNA tensioner platform is reported that shortens the time of drug delivery to less than 3 s, and that of cellular mechanical force analysis to 30 min. The platform adopts a nanochannel structure to localize a safe electric field for cell perforation, while enhancing delivery speed by 10 3 times for intracellular delivery, as compared to molecular diffusion in coculture methods. The platform is further equipped with a DNA tensioner to detect cellular mechanical force for quantifying cell viability after drug treatment. Systematic head-to-head comparison, by analyzing FDA (food and drug administration)-approved drugs (paclitaxel, doxorubicin), demonstrated the platform with high speed, efficiency, and safety, showing a simple yet powerful tool for clinical drug screening and development.
研究领域:
生物技术
·
药学
·
细胞生物学
·
药物开发
·
精准医学
✓ 已验证
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2025
·
IF 2.5
Zhongliang Guo,Yuqin Zhu,Yu Mi,Zhiyong Zhang,Huiying Wen,Lubin Liu,Miaojun Xu,Bin Li
In this study, a phosphorus-containing thermotropic liquid crystal copolyester (p-TLCP) was synthesized via melt polycondensation using 2-(6-oxid-6H-dibenzo<1,2>oxaphosphorin-6-yl)-1,4-benzenediol (DOPO-HQ), terephthalic acid (TPA), p-hydroxybenzoic acid (p-HBA), and dimethyl terephthalate (DMT) as raw materials with a molar ratio of 3:3:2:2. The flame-retardant p-TLCP was subsequently incorporated into polybutylene terephthalate (PBT) to fabricate composites. The thermal properties, flame retardancy, and mechanical performance of the PBT/p-TLCP composites were systematically investigated through limiting oxygen index (LOI), vertical burning (UL-94), cone calorimetry, dynamic thermomechanical analysis (DMA), tensile/impact testing, scanning electron microscopy (SEM), coupled with laser Raman spectroscopy (LRS) and Thermogravimetric-Fourier Transform Infrared Spectroscopy (TG-FTIR). Results revealed that the flame retardancy and mechanical properties of the composites were markedly improved with increasing p-TLCP content. When the p-TLCP addition was 10.0 wt.%, the LOI value of the composite increased from 22.0% (pure PBT) to 27.0%, achieving a UL-94 V-0 rating; at a p-TLCP loading of 12.5 wt.%, the peak heat release rate (PHRR) and total heat release (THR) decreased by 22.4% and 35.8% relative to pure PBT, respectively, while the storage modulus and tensile strength were elevated by 22.8% and 19.4%, with impact strength reaching 30.5% enhancement, demonstrating optimal comprehensive performance.
研究领域:
高分子科学
·
材料工程
·
化学合成
·
热分析
·
阻燃性能
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Zhangchao Mo,Xuesong Jiang,Xiaoxiao Zhu,Juxuan Ding,Boyuan Ban,Jifei Sun,Jian Chen
Glass fiber powder contains two distinct forms: crumb-shaped and rod-shaped glass fiber powder particles. The shape and size of the particles in glass fiber powder have a great influence on its application. In order to separate rod-shaped glass fiber, the effects of different dispersants, such as SHMP, NaOL, and Na 2 SiO 3 on them were investigated by settling experiments. Zeta potential, X-ray photoelectron spectroscopy (XPS), optical microscope, and other methods were used to analyze the adsorption behavior and settling mechanism. Three-point bending experiment and dynamic mechanical analysis (DMA) were used to evaluate the performance of epoxy resin composites reinforced with the raw glass fiber powder and the rod-shaped glass fiber powder. The results show that SHMP can effectively separate crumb-shaped glass fiber powder and rod-shaped glass fiber powder, leading to a notable increase in sedimentation recovery difference, up to Δ=51.08 %. A preferential sedimentation separation mechanism is proposed to elucidate the settling mechanism. When the content of glass fiber powder and rod-shaped glass fiber is 5 %, the glass transition temperature shifts significantly towards higher values, leading to the optimum comprehensive mechanical properties of the composites. Compared with the original epoxy resin, the flexural strength increased by 10.38 % to 95.18 MPa and by 20.11 % to 103.57 MPa. Similarly, the storage modulus increased by 14.14 % to 2083 MPa and by 21.64 % to 2220 MPa.
研究领域:
材料科学
·
复合材料
·
高分子科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2023
·
IF 2.1
Jinshui Lu,Jinyuan Zhang,Heng Liu,Weipeng Chen,Jiangrong Luo,Ziqing Wang,Tingting Cui,Yonggang Min,Yidong Liu
In this work, a new diamine was designed by connecting flexible structures such as ether bond and aliphatic carbon chain between benzene rings, and was synthesized and purified through simple reactions such as Suzuki reaction. Finally, a series of polyimide (PI) films were synthesized by copolymerization with 4.4`-diaminodiphenyl ether (ODA)\pyromellitic dianhydride (PMDA) in different proportions. We prepared polyimide films with new monomer copolymerization ratios of 1% (PI-1), 5% (PI-2), 10% (PI-3), and 20% (PI-4). The polyimide films showed excellent glass transition temperatures, which were attributed to their unique bent architectures. The mechanical and thermal properties of the thermosets were studied using tensile testing, static thermomechanical analysis (TMA), and thermogravimetric analysis (TGA). As the results, the films exhibited the optimal glass transition temperatures (317.56°C–381.91°C), and the component with the highest copolymerization ratio has a 15% decrease in glass transition temperature compared to the component without copolymerization. Moreover, PI-1-PI-4 showed good heat resistance in the N2 atmosphere. The temperatures corresponding to a 5% heat loss in the films (T5%) were 458.12 °C–548.75°C, respectively.
研究领域:
材料科学
·
高分子化学
·
热分析
✓ 已验证
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Jingjing Qin,Jiaming Liu,Dingsong Wang,Liyan Liang,Chaolong Yang,Maoping Lyu
During recent decades, intrinsic self-healable thermosetting materials by integrating dynamic covalent bonds (DCBs) have been widely used. In this study, through the molecular structure design, a flexible polyurethane curing agent based on hindered urea bonds (HUBs) was successfully prepared by the reaction of Hexamethylene diisocyanate trimer (THDI) and sterically hindered secondary amine, which was further used as a curing agent to cure epoxy resin. Therefore, a new type of epoxy thermosetting material (TBEP) with dynamic hindered urea bond was synthesized and the preparation and performance of TBEP were confirmed and characterized by infrared spectroscopy, thermomechanical analysis and thermal stability test. The results show that the HUBs are successfully integrated into the epoxy resin and endow the epoxy thermosets with brilliant self-healable, reprocessable, recyclable and shape memory properties. Simultaneously, the existence of flexible polyurethane chain in the crosslinking network effectively solves the brittleness problem of epoxy resin, promotes the mechanical performance of epoxy thermosets, and further broadens the its application field. This work provides a simple and efficient method to design flexible and self-healable epoxy thermosets with brilliant mechanical performance, which solves the contradiction between outstanding mechanical properties and self-healing ability of epoxy resin to some extent, and is environmentally friendly and cost-effective in acquisition and application.
研究领域:
材料科学
·
高分子化学
·
可持续材料
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Shiyun Zhou,Tian Xia,Shuo Wu,Wanting Zhang,Jianhui Xu,Yi Yang,Youbing Li,Guangxian Li
Self-healing bitumen can significantly enhance the durability and service life of bituminous pavement, thereby reducing the need for frequent maintenance and repairs. In this study, isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), and isophorone diamine (IPDA) were utilized to design asymmetric dynamic hard segments, imparting self-healing properties to polyurethane even at room temperature. Particular emphasis was placed on hydrogen bonding, as its reversible formation serves as a primary mechanism for the self-healing characteristics of the material. During the synthesis of polyurethane (PU), two different composition ratios were employed to produce two types of PU with distinct chemical structures, molecular weights, and dynamic crosslink densities, which were characterized using NMR, FTIR, GPC, and DMA, respectively. Furthermore, these two PU types exhibited varying mechanical properties and glass transition temperatures, leading to differences in the rheological properties of the corresponding PU-modified bitumen. Dynamic frequency sweep test results indicated that bitumen modified with PU exhibiting higher molecular weight and narrower molecular weight distribution had superior rutting resistance and enhanced room-temperature self-healing capabilities. The underlying reasons for this improvement can be attributed to the hydrogen bonding present in the PU as well as the phase separation structure between the PU and bitumen.
研究领域:
材料科学
·
高分子化学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）