JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 1
·49640
·
IF 2.52
Chunyan Qu,Yao Tang,Dezhi Wang,XuPeng Fan,Hongfeng Li,Changwei Liu,Kai Su,Daoxiang Zhao,Jiaqi Jing,Xiao Zhang
Limitations in the properties of polyamide PA66, such as low glass transition temperature and high water absorptivity, limit its applications. Introduction of amorphous polyimide segments into the PA66 main chain lowers the glass transition temperature and melting temperature and also improves its processability. PA66-polyimide (PA-PI) copolymers with different weight ratios of PI are prepared by high temperature and high-pressure solution polymerization. The degree of crystallization of PA-PI copolymers decreases with increasing PI content. The melting point decreases from 261°C for PA66 to 223°C for PA-PI-4. Dynamic mechanical analysis shows that the T g increases from 70 to 90°C, and the storage modulus can be well maintained. Rheological studies show that the temperature for processing can reach 70°C. Copolymers with different PI contents show different processing viscosities. In addition, water absorptivity (about 1.8%) and dielectric constant values of PA-PI and PA6/6T are similar.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2025
·Vol. 17
·期 11
·1537
·
IF 4.9
Haoyang Zhang,Jiyu He,Xiangmei Li
PA66 is a widely used engineering plastic, but its flammability reduces safety during application. The 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) and its derivatives are a class of flame retardants with excellent flame-retardant efficiency, which can significantly improve the flame retardancy of PA66. This work synthesized a DOPO derivative flame retardant, DT, containing multiple P/N elements and comprehensively characterized its structure using FTIR and NMR. Flame-retardant PA66 materials were prepared by twin-screw extrusion blending with PA66, and their thermal stability, crystallization properties, flame retardancy, and mechanical properties were investigated. When the DT content reached 15%, the vertical burning classification test achieved the UL-94 V-0, and the limiting oxygen index (LOI) rose up 27.2%. In the cone calorimeter test, the peak of heat release rate (PHRR) and total heat release (THR) of the material decreased significantly, and a distinct char layer formed, increasing NH3release and decreasing the C-H structure after combustion, improving PA66 flame-retardant properties.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 1
·47488
·
IF 2.188
Hao Fu,Yihua Cui,Jipeng Lv
A “trinity” reactive flame retardant (TRFR) was successfully synthesized from pentaerythritol, phosphorus oxychloride (POC), and p -aminobenzoic acid in two steps. The flame retardant polyamide 66 (PA66) was prepared by polymerizing TRFR with PA66 salt; the structural changes during the heating process, the morphology, and composition after combustion of flame retardant PA66 were analyzed. Fourier transform infrared, scanning electron microscopy, and Raman analysis results showed that the TRFR structure on flame retardant PA66 decomposed at the temperature of 25–550 °C, forming compounds containing phosphorus, carbon, and nitrogen, respectively. These compounds promoted the dehydration of the combustion surface to form char, increased the char formation rate, and produced nonflammable gases, resulting in a dense, porous, noncombustible carbon layer. The carbon layer may isolate oxygen and heat, thereby preventing the polymer from sustainability of combustion. When the TRFR salt content was 3%, TRFR flame retardant PA66 has excellent flame retardancy with limited oxygen index value of 29 and UL94 of V-0 rating. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 47488.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 5
·1183
·
IF 5
Yanpeng Wu,Tonghui Yang,Yongchang Cheng,Tao Huang,Bin Yu,Qilin Wu,Meifang Zhu,Hao Yu
Preparing flame-retardant polyamide 66 (PA66) fibers through melt spinning remains one of the biggest challenges nowadays. In this work, dipentaerythritol (Di−PE), an eco-friendly flame retardant, was blended into PA66 to prepare PA66/Di−PE composites and fibers. It was confirmed that Di−PE could significantly improve the flame-retardant properties of PA66 by blocking the terminal carboxyl groups, which was conducive to the formation of a continuous and compact char layer and the reduced production of combustible gas. The combustion results of the composites showed that the limiting oxygen index (LOI) increased from 23.5% to 29.4%, and underwriter laboratories 94 (UL-94) passed the V-0 grade. The peak of heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) decreased by 47.3%, 47.8%, and 44.8%, respectively, for the PA66/6 wt% Di−PE composite compared to those recorded for pure PA66. More importantly, the PA66/Di−PE composites possessed excellent spinnability. The prepared fibers still had good mechanical properties (tensile strength: 5.7 ± 0.2 cN/dtex), while maintaining good flame-retardant properties (LOI: 28.6%). This study provides an outstanding industrial production strategy for fabricating flame-retardant PA66 plastics and fibers.Keywords:PA66;Di−PE;flame retardance;melt spinning;flame retardant mechanism
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 15
·5191
·
IF 3.748
Qiupeng Wu,Zhiheng Yu,Fengli Huang,Jinmei Gu
Triboelectric nanogenerators (TENGs) are considered to be the most promising energy supply equipment for wearable devices, due to their excellent portability and good mechanical properties. Nevertheless, low power generation efficiency, high fabrication difficulty, and poor wearability hinder their application in the wearable field. In this work, PA66/graphene fiber films with 0, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt% graphene and PVDF films were prepared by electrospinning. Meanwhile, TENGs were prepared with PA66/graphene fiber films, PVDF films and plain weave conductive cloth, which were used as the positive friction layer, negative friction layer and the flexible substrate, respectively. The results demonstrated that TENGs prepared by PA66/graphene fiber films with 2 wt% grapheme showed the best performance, and that the maximum open circuit voltage and short circuit current of TENGs could reach 180 V and 7.8 μA, respectively, and that the power density was 2.67 W/m2when the external load was 113 MΩ. This is why the PA66/graphene film produced a more subtle secondary network with the addition of graphene, used as a charge capture site to increase its surface charge. Additionally, all the layered structures of TENGs were composed of breathable electrospun films and plain conductive cloth, with water vapor transmittance (WVT) of 9.6 Kgm−2d−1, reflecting excellent wearing comfort. The study showed that TENGs, based on all electrospinning, have great potential in the field of wearable energy supply devices.Keywords:triboelectric nanogenerators;PA66/graphene fiber films;PVDF films;performance;wearing comfort
研究领域:
材料科学
·
纳米技术
·
能源技术
·
可穿戴设备
✓ 已验证
DOI
PubMed
高影响因子
THIN-WALLED STRUCTURES
·
2024
·
IF 5.7
Chenxi Yin,Yonghui Li,Ping Wang,Yuanyuan Li,Yan Zhang,Dongmei Hu
Carbon nanotube (CNT) has potential application in many fields owing to its excellent properties, but the weak Van der Waals forces between randomly arranged tube bundles limit their mechanical properties. In this paper, CNT films were prepared by floating catalyst chemical vapor deposition (FCCVD), whereas PA66 resin was introduced via impregnation and hot press curing in order to further improve the mechanical tensile properties and environmental resistance of the films. The results demonstrate that the tensile properties of PA66-impregnated CNT film are significantly improved. When the mass fraction of PA66 is 1 %, the composite film exhibits the best tensile properties under quasi-static conditions, with a tensile strength of 528 MPa and an energy absorption (EA) value of 109.5 MJ/m 3 . Plus, at the high strain rate of 2900 s −1 , the strength and EA of CNT film/PA66 composite can reach 534 MPa and 107 MJ/m 3 , respectively. The results in present research can provide a feasible and effective strategy for the design of CNT composite film with high mechanical tolerance which will broaden the application field to a large extent.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Jianxiang Lin,Shaoping Chen,Zhenyang Qi,Wenhao Fan,Qiang Zhang,Tao Zhang,Zhiyi Zhang,Qingsen Meng
Significant physicochemical differences between metals and thermoplastics pose challenges for achieving strong interfacial bonding under conventional forming processes. This work presents a novel approach using an external electric field (EEF) to activate functional groups at metal-polymer interfaces, forming complex chemical bonds and strong heterogeneous connections. Silane-modified PA66 composites filled with high-content aluminum spheres were fabricated. Experimental results show that the chemical bonding between Al and PA66 under EEF is due to extensive functional group reactions and secondary bonding within Al-PA66 interface, achieving a remarkable ultimate tensile strength of 65 MPa for the composite with 50 wt% Al filling. Moreover, dissimilar joints of composites and 6061T6, made by friction stir welding, exhibit high strength due to the formation of a “Novel Net-Metallurgy Bonding Structure” during frictional heat transfer. This work provides new insights and theoretical guidance for interfacial bonding in metal-polymer heterogeneous interfaces.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 8
·e53536
·
IF 3.057
Wengui Wang,Fan Wang,Heng Li,Yaochi Liu
To improve the flame retardancy of PA6/PA66 copolymer, a phosphorus-nitrogen flame retardant DDP-M was successfully synthesized via melt condensation reaction between 2-[(5-oxo-6H-phosphanthridin-5-yl)methyl]butanedioic acid (DDP) and melamine (Mel). Its structure, product composition, and thermal stability were characterized by FTIR, nuclear magnetic resonance spectroscopy (NMR), matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and thermogravimetric analysis (TGA). The results suggested that DDP-M was a hybrid flame retardant. A series of flame-retardant PA6/PA66 composites were prepared by melt extrusion. Their thermal stability and flame retardancy were assessed by differential scanning calorimetry (DSC), TGA, limiting oxygen index (LOI), and vertical burning test (UL-94). The combustion behavior demonstrated that DDP-M can effectively improve flame retardancy, achieving 32% of LOI value and UL-94 V-0 rating with only 9 wt.% addition. No melt dripping was accomplished by adding 12% DDP-M. The high dose (15%) harmed the flame-retardant properties. The results of pyrolysis gaseous productions analysis and residual carbon analysis revealed the flame-retardant mechanism of DDP-M was a synergistic effect of melamine inducing gaseous phase flame retardancy and highly condensed P-N char layers inducing condensed phase flame retardancy. The composites retained good mechanical properties due to the good dispersibility and compatibility between polyamide and DDP-M.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2024
·
IF 8.3
Chaojun Wang,Xuewen Cheng,Wei Huang,Bing Yu,Nanying Ning,Ming Tian
Fiber-reinforced rubber composites (FRRC) are widely used in tires, hoses, conveyor belts and other fields. Currently, the industry heavily relies on the resorcinol-formaldehyde-latex (RFL) system to enhance interfacial adhesion performance of FRRC; however, both resorcinol (R) and formaldehyde (F) pose significant risks to human health and the environment. Thus, some two-step RF-free dipping systems have been developed to replace RFL system. Nevertheless, these complex two-step systems face challenges during industrialization. In this study, we proposed a novel one-step eco-friendly dipping system (PCGL) for polyamide66 (PA66)fibers. By using the new system, a solid transition bridge between PA66 fiber and rubber matrix can be formed, due to the bonding between PA66 and isocyanate, the interaction among polyacrylic acid resin, isocyanate and epoxy, the catalytic effect of triethanolamine, as well as the co-crosslinking of styrene-butadiene-vinyl-pyridine latex and rubber. The interfacial adhesion performance of PA66 fiber/rubber composites treated by PCGL with optimized ratio of epoxy groups/isocyanate groups can reach more than 90% of RFL level, meeting industry requirements for high interfacial bonding performance, while maintaining strength and safety of composites. The mechanism of largely enhanced interfacial adhesion was revealed through the analysis of modulus transition and co-crosslinking at the composite interface.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2023
·
IF 13.1
Wei Huang,Yingzhe Li,Hui Zhao,Wencai Wang,Bing Yu,Nanying Ning,Ming Tian,Liqun Zhang
Fiber-reinforced rubber composites (FRRC) are widely used in automobile, aero tires, and conveyor belts , etc. In order to obtain high performance of FRRC, strong interfacial adhesion between fibers and rubber is a key. Resorcinol-formaldehyde-rubber latex (RFL) as the widely used dipping system in industry can do harm to human health and environment because of the release of resorcinol and formaldehyde in air. In this study, a new kind of eco-friendly dipping system for PA66 fibers was designed and successfully prepared, especially to meet the harsh service environment of aero tires. Such new dipping system is composed of the first coating of tea polyphenols (TP) on fiber surface through the hydrogen bonding between TP and PA66 fibers followed by the second coating with the mixture of glycerol triglycidyl ether (GTE), 2-ethyl-4-methylimidazole (MZ) and styrene-butadiene-vinyl-pyridine (VP) latex, in which the covalent bonding between TP and GTE, the crosslinking of GTE and the co-crosslinking of VP and NR matrix result in the formation of a solid transition bridge between PA66 fibers and NR matrix. By using such eco-friendly dipping system with optimized ratio of MZ/GTE, PA66 fibers/NR composites exhibit equivalent interfacial adhesion and aging stability as that using RFL system, while maintaining the strength and safety of composites. More importantly, PA66 fibers using the eco-friendly dipping system exhibit even better fatigue stability of interfacial adhesion after 46800 times of cyclic fatigue than that using RFL system. The relationship between the dipping layer structure and the interfacial adhesion of the composites was established.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Yang Song,Nan Zheng,Xiaoli Dong,Jiefeng Gao
Interleaf is often used to increase the interlaminar fracture toughness of carbon fiber/epoxy (CF/EP) composites, but it remains a challenge to develop high-performance interleaves that can greatly improve the toughness while simultaneously maintaining the in-plane properties. In this study, the carboxylated carbon nanotubes were uniformly decorated onto the surface of electrospun PA66 nanofibers by combination of ultrasonication and interfacial hydrogen bonding, and the obtained flexible nanofiber composite was served as interleaves in the CF/EP laminate. It is found that the modes I and II interlaminar fracture toughness of CNT-COOH/PA66 nanofiber interleaved laminate increases by 122 and 81% compared to the pristine CF/EP. Also, the flexural strength and flexural modulus was enhanced due to the reinforcing effect of the CNT-COOHs. The toughening mechanisms for both modes I and II fracture are investigated in detail based on the morphology of the delamination surface of the laminates.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Pengcheng Song,Shuaijie Li,Peng Chen,Xiaoming Li,Zhihui Zhao,Weichao Chen
With the rapid industrial development, massive untreated polluting gases are discharged, causing irreversible environmental damage. Membrane filtration technology efficiently removes airborne pollutants, and preparing high-performance filter materials via structural adjustment offers a simple solution. In this work, the Polyamide 66 (PA66)/ Formic acid (FA) spinning solution, characterized by high viscosity, electrical conductivity, and relatively low surface tension, facilitates the fabrication of nanofibers with a diameter of merely 166 nm, rendering it an efficient intermediate filter layer. Conversely, the PA66/ 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) spinning solution yields a thick filament layer with a diameter of 638 nm, which imparts mechanical properties to the sandwich-structured nanofiber membranes on both lateral sides. The resulting sandwich structure membrane exhibits exceptional filtration performance, achieving a PM 0.3 capture efficiency of 99.5 % with a low-pressure drop of 63 Pa. After multiple air-filtration cycle tests, the membrane maintains stable filtration performance, demonstrating great potential in air filtration applications. Additionally, the oil-water separation effect can reach 99.79 % with water flux of 6534 L·m⁻²·h⁻¹ , which could be maintained after multiple cycle tests. This study presents a simple and effective approach to control the microstructure of nanofiber membrane, achieving eminent filtration performance and oil-water separation.
研究领域:
材料科学
·
环境工程
·
纳米技术
·
化学工程
✓ 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）