Polymers
·
2023
·Vol. 15
·期 8
·1887
·
IF 5
Hui Fang,Guifeng Li,Kai Wang,Fangjuan Wu
This study investigates the effect of adding stearic acid (SA) on the thermal conductivity of polyamide 6 (PA6)/boron nitride (BN) composites. The composites were prepared by melt blending, and the mass ratio of PA6 to BN was fixed at 50:50. The results show that when the SA content is less than 5 phr, some SA is distributed at the interface between BN sheets and PA6, which improves the interface adhesion of the two phases. This improves the force transfer from the matrix to BN sheets, promoting the exfoliation and dispersion of BN sheets. However, when the SA content was greater than 5 phr, SA tends to aggregate and form separate domains rather than being dispersed at the interface between PA6 and BN. Additionally, the well-dispersed BN sheets act as a heterogeneous nucleation agent, significantly improving the crystallinity of the PA6 matrix. The combination of good interface adhesion, excellent orientation, and high crystallinity of the matrix leads to efficient phonon propagation, resulting in a significant improvement in the thermal conductivity of the composite. The highest thermal conductivity of the composite is achieved when the SA content is 5 phr, which is 3.59 W m−1K−1. The utilization of a composite material consisting of 5phr SA as the thermal interface material displays the highest thermal conductivity, and the composite also demonstrates satisfactory mechanical properties. This study proposes a promising strategy for the preparation of composites with high thermal conductivity.Keywords:thermal conductivity;polyamide;boron nitride;stearic acid
研究领域:
材料科学
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热管理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Wenwen Wang,Aisen Jiang,Hao Zhang,Junjie Wang,Xiaoguang Li,Congang Fu,Xiaohan Yang,Ke Liu,Dong Wang
The growing demand for polymeric materials has encouraged industries and the academic community to develop materials with improved mechanical properties, particularly those that can be used in various fields. Polyamide 6 (PA6) is a versatile engineering plastic material with various advantageous properties; however, improving its toughness and hydrophobicity is conducive to expanding its application. In this work, α, ω-aminopropyl-terminated poly(methyltrifluoropropylsiloxane) prepolymer (APMFS) was synthesized for its outstanding flexibility and hydrophobicity. It was then covalently incorporated into a PA6 backbone through straightforward large-scale melt polymerization. The functionalized PA6 exhibited the highest breaking strength and toughness of approximately 59.6 MPa and 426.3 MJ/m3, respectively. Moreover, the impact strength of PA6-APMFS reached 63.7 kJ/m2, more than twice that of conventional PA6. The water contact angle was measured at its highest, 94°, with water absorption reduced to 0.5 wt %. Microfibers exhibited a very low wicking height of 7.5 cm. Subsequently, functionalized nanofibrous membranes and foams were applied for self-cleaning, oil/water separation, and thermal insulation, showcasing excellent potential for protective and water purification applications. This work illustrates the multifunctional application advantages of modified PA6.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2024
·
IF 4.8
Wenqi Zou,Kaiqiang Luo,Jun Xu,Munan Qiu,Jing Tian,Zhanpeng Wu,Baohua Guo
In this study, the challenges of brittleness and flammability in Polyamide 6/glass fiber (PA6/GF) composites, which are crucial for heat-resistant and stress-bearing structural parts, are addressed. Polyphosphazene (PZ) elastomers, known for their exceptional flame-retardant properties, are introduced to enhance the robustness and safety of these composites. Specifically, poly(diaryloxy)phosphazene (PDAP) and poly(difluoroalkoxy)phosphazene (PDFP) are utilized, both contributing to the improved toughness and flame resistance of the PA6/GF composites. Experimental results show that PDAP mainly played the role of solid-phase flame retardant, while PDFP mainly acted the role of gas-phase flame retardant. For PA/PZs composites without adding GF, PDFP plays a more efficient flame retardant effect than PDAP. By introducing 15 Vol% of PDFP, the limiting oxygen index (LOI) of the composite reached 26.1%, while the notched impact strength increased by 297%. For PA/PZs/GF composites, PDAP plays a better flame retardant role than PDFP. Under the action of 30 vol% GF and 15 vol% PDAP, the LOI of PA6/PDAP/GF composite reached 26.8%, and the notch impact strength improved to 18.7 kJ/m 2 , which is 165% higher than that of PA6/GF, and the UL-94 test reaches V-0 level. The findings of the study highlight the potential of PDAP and PDFP to act as dual-function modifiers. These modifiers can considerably ameliorate both the impact resistance and flame retardancy of PA6 and PA6/GF composites. Such dual enhancement surpasses the typical trade-offs seen in conventional composites, indicating a constructive direction for future material innovation. Highlights Polyphosphazenes simultaneously enhance PA6's toughness & flame resistance. Distinct flame retardant mechanisms found in PDAP and PDFP. GF presence alters PDAP and PDFP's flame retardant efficacy. PDAP shows superior flame resistance in GF-reinforced PA6 composites. Without GF, PDFP outperforms PDAP in enhancing flame retardancy.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 15
·2496
·
IF 4.329
Shiyou Tian,Jicong Zhang,Qiong Zhou,Limei Shi,Wenwen Wang,Dong Wang
We report photochromic polyamide 6 (PA6) which was synthesized by hydrolyzed ring-opening polymerization of ε-caprolactam with spiropyran (SP) embedded in the polymer chains. It indicated that crystallinity degree of the resulting copolymers was decreased since only PA6 segments can crystallize with increasing content of SP modifier. Meanwhile, toughness of photochromic PA6 was decreased. The photochromic property analysis indicated that the sample with more flexibility and more content of SP was more sensitive to UV light at the beginning of irradiation than other samples and its color after being irradiated for 1 min tended to reddish. Investigation revealed that the UV-vis absorbance of SP-PA6-3 had negligible decay after 10 cycles, which indicated SP-modified PA6 possessed excellent photoresponse reversibility and fatigue resistance.Keywords:photochromic;polyamide 6;spiropyran;structure and properties
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2016
·Vol. 34
·期 4
·399-406
·
IF 1.811
Wang Zhi-liang,Xu Jia-li,Yuan Qian,Shibraen Mahmoud H. M. A.,Xu Jian,Yang Shu-guang
Hydrothermal processing of polyamide 6 (PA6) with the presence of lanthanum chloride (LaCl 3 ) was studied in the temperature region from 160 °C to 250 °C. PA6 will be dissolved in the superheated water when temperature is above 160 °C. And as PA6 is dissolved, hydrolysis will happen, which makes PA6 chains degrade. By adding LaCl 3 in the hydrothermal environment, the PA6 hydrolysis will intensify, especially when the hydrothermal temperature is higher than 200 °C. When the hydrothermal system cools down, the hydrolyzed PA6 segments will crystallize from the solution or remain dissolved in the solution depending on molecular weight. In addition, the hydrolyzed compound of LaCl 3 would affect the crystallization of PA6 segments with proper size, and γ phase would be presented.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SN Applied Sciences
·
2019
·Vol. 1
·期 11
·1-8
·
IF 0
Zhang Xue,Sun Lei,Chen Yingbo,Yin Cuiyu,Liu Dongqing,Ding Ermin
Flame retardant polyamide 6 (PA6) composites (PA6/PTCDA) were prepared by in situ polymerization of caprolactam with adding 0.01–2.5 wt% perylene-3,4,9,10-tetracar-boxylic dianhydride (PTCDA). The structure and properties of PA6/PTCDA composites were studied by Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, thermal conductivity, and limiting oxygen index (LOI) measurements. The results indicated that the crystallization of the PA6 chains was suppressed with 2.5 wt% PTCDA, and the LOI of the composite was 29.5. At the same time, the addition of PTCDA made the composites form a coke layer in the process of combustion, protecting the flammable components from volatilization and enhanced the flame retardant performance of the composites. This indicated that the PA6/PTCDA composite prepared by in situ polymerization possessed good flame retardant properties.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
POLYMER ENGINEERING AND SCIENCE
·
2018
·
IF 1.551
Miao-Jun Xu,Hai-Chao Liu,Kun Ma,Bin Li,Zhi-Yong Zhang
A novel flame-retardant chain extension agent (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide)-3,5-triglycidyl isocyanurate defined as DOPO-TGIC was synthesized, and its chemical structure was well characterized and confirmed. The effect of DOPO-TGIC as a synergistic agent on the flame retardancy, rheology, thermal and mechanical properties of polyamide 6/aluminum diethylphosphinate (PA6/AlPi) composites were investigated in details. The results demonstrated that PA6/AlPi/DOPO-TGIC composites (1.6 mm) successfully passed UL-94 V-0 rating with the limiting oxygen index value of 30.5% when the total loading amount of AlPi/DOPO-TGIC was 10 wt%. In order to achieve the equal flame-retardant level, the individual AlPi was required 14 wt%. The incorporated DOPO-TGIC improved the complex viscosity of PA6/AlPi/DOPO-TGIC composites due to the chain extending reaction between epoxide groups in DOPO-TGIC and the terminal groups of PA6 matrix. The mechanical performance of PA6/AlPi/DOPO-TGIC composites was also improved compared with that of PA6/AlPi composites. DOPO-TGIC stimulated to the formation of more sufficient and compact char layer during combustion. The higher melt viscosity and compact char layer of PA6 composites effectively constrained the volatilization of flammable gases, thus the heat release was reduced. Consequently, the introduction of DOPO-TGIC simultaneously enhanced the flame retardant and mechanical properties of PA6/AlPi/DOPO-TGIC composites compared with that of PA6/AlPi composites. POLYM. ENG. SCI., 59:E206–E215, 2019. © 2018 Society of Plastics Engineers
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
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Feng Gao,Ke Liu,Yongjun Wang,Junming Dai,Wenxing Chen,Wangyang Lu
Direct spinning of polyamide 6 (PA 6) fibers, traditionally impeded by the presence of approximately 10% residual monomer and oligomers in the polymerized form, has been made feasible through our innovative approach. Current extraction methods predominantly employ hot water to extract monomer and oligomers. However, this approach is characterized by time-consuming procedures, high energy consumption, and substantial water usage. Therefore, in this study, a straightforward falling-film devolatilization method is proposed to synchronize the liquid-phase viscosity enhancement and oligomer removal of PA 6. PA 6 industrial yarns were successfully produced using devolatilized PA 6 (D-PA 6) obtained by this method. The viscosities of D-PA 6 samples were increased from 2.5 and 2.8 to 2.8 and 3.4, their monomer contents were reduced to 0.26%, and their dimer and residual oligomer contents were reduced to 0.54 and 2.54%, respectively, with a lower removal of dimer and trimer. The process led to a wider molecular weight distribution, consistent with that typical of PA 6 spinning. The obtained PA 6 industrial yarn exhibited a high degree of crystallinity, and its orientation, thermal properties, and mechanical properties were comparable to those of conventional yarn. Although its dyeing ability was slightly compromised, this did not hinder the practical application of the PA 6 industrial yarn. The falling-film devolatilization process enables simultaneous viscosity enhancement and devolatilization without the need for hot-water extraction (24 h) and drying (24 h), drastically shortening the production time from more than 48 h to less than 10 h, thereby greatly reducing energy consumption and wastewater discharge. This study provides technical guidance for the sustainable industrial production of PA 6 industrial yarn by direct melt-spinning, which significantly reduces energy and environmental impacts while improving production efficiency.
研究领域:
材料科学
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纺织工程
·
化工
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2020
·
IF 4.271
Lei Sun,Ming Cao,Fan Xiao,Jiaopeng Xu,Yingbo Chen
Frictional and wear properties of polyamide 6 (PA6) are very important for its use as anengineering plastic. In this study, octaamino-polyhedral oligomeric silsesquioxane (POSS) functionalized graphene oxide (GO) was used to fabricate a PA6/reduced GO-POSS (rGO-POSS) nanocomposites. Compared with PA6, the PA6/rGO-POSS nanocomposites with 0.3 wt% GO-POSS has a decrease of friction coefficient by 86.36% from 0.44 to 0.06. The depth and width of the wear scar were reduced by 79.64% and 70.69%, respectively. Meanwhile, the wear rate reached the lowest and dropped by about 65.72%. The research found that GO-POSS is self-fixed in the matrix and effectively increases the interface bonding strength .
研究领域:
材料科学
·
工程学
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Bohan Liang,Ke Liu,Junming Dai,Wenxing Chen,Wangyang Lu
A polymer-type flame retardant (PFR) based on a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative was synthesised here to improve the flame retardancy of polyamide 6 (PA6). The chemical structure and thermal property of the PFR were characterised by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The PFR and PA6 were melt-blended to obtain a flame-retardant polyamide 6 (FRPA6). Its thermal property, mechanical property and flame retardancy were characterised via TGA, DSC and tensile, impact, vertical burning and limiting oxygen index (LOI) tests. Its flame-retardant mode of action was analysed by scanning electron microscopy, FTIR spectroscopy, cone calorimetry and pyrolysis-gas chromatography-mass spectrometry. The FRPA6 with a phosphorus content of 3000 ppm passed the UL-94 V-0 rating, and the LOI of the FRPA6 with a phosphorous content of 5000 ppm reached 28.8 %. Compared with pure PA6 , the peak heat release rate, total heat release and effective heat of FRPA6–5000 were reduced by 35.4 %, 21.9 % and 26.5 %, respectively. These results indicate that the flame-retardant mode of action of PFR mainly involved the quenching effect of phosphorus-containing radicals in the gas phase.
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 PART B-ENGINEERING
·
2024
·
IF 12.7
Yanlu Sun,Xilin Pei,Zhengqi Wang,Dequn Wu,Xueli Wang,Jianyong Yu,Ruchao Yuan,Faxue Li
In the pursuit of enhancing the fire safety of polyamide 6 (PA6), the addition of flame retardants generally leads to hydrogen bond dissociation, which results in detrimental effects on the mechanical properties of PA6 composites and impedes processing and application in the textile field. In this study, a macromolecular flame retardant, PPB, designed with hydrogen bond donor-acceptor spacing aligned with PA6, was synthesized to increase the number of hydrogen bonds. The addition of 10 wt% PPB to the PA6 matrix (PA6/PPB10) endowed the composite with the limiting oxygen index (LOI) increased to 31.6 % and V-0 rating in the vertical burning (UL-94) test. PA6/PPB10 also exhibited significant enhancement in tensile strength by 12.6 % compared to pure PA6 and demonstrated a superior ultraviolet protection factor (UPF) value of 573, greatly exceeding the value of 3 for PA6. The quenching effect, diluting effect in the gas phase, and hydrogen bond interactions between PPB and PA6 backbones imparted PA6/PPB composites with satisfactory flame retardancy and mechanical properties. As a representative example, PA6/PPB10 was melt-spun into filaments with a pleasing tenacity of 3.6 cN/dtex and self-extinguishing capability within 5 s after ignition, confirming the sustained comprehensive properties after spinning and drawing into filaments.
研究领域:
材料科学
·
纺织工程
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2020
·Vol. 60
·期 4
·710-716
·
IF 1.917
Hui Fang,Denghui Li,Fangjuan Wu,Xiangfang Peng,Anlin Chen,Lingjie Zhang,Sheng Chen
Polyamide 6/boron nitride (PA6/BN) composites were synthesized via anionic ring-opening polymerization using ε-caprolactam as the monomer and functional boron nitride (f-BN) as the thermal conductive filler. Besides the homopolymerized PA6, some PA6 molecule chains would grow from the f-BN sheets through the “grafting from” strategy. Compared with unfunctional hexagonal BN (h-BN), the introduction of f-BN not only improved the dispersion of f-BN in the matrix but also enhanced the interface bonding between f-BN and PA6. The homogeneous dispersion of f-BN in the PA6/f-BN composite favored the formation of the continuous thermal conductive paths or network at a low f-BN loading, and the good interface bonding reduced the phonon scattering in the interface, which improved the thermal conductivity (TC) of the PA6/f-BN composite by 66.0% compared with that of the pure PA6, when only 5 wt% f-BN was added. In contrast, with the same content of unfunctional h-BN loading, the TC of the corresponding composite merely improved by 29.7%. Moreover, Young's modulus and yield strength of PA6/f-BN composites had increased obviously with the introduction of f-BN, whereas those of PA6/h-BN composites showed small fluctuation with the same contents of BN. POLYM. ENG. SCI., 60:710–716, 2020. © 2020 Society of Plastics Engineers
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
危险品化学品经营许可证（带存储）