Polymers
·
2019
·Vol. 11
·期 2
·364
·
IF 3.164
Ya Liu,Gaokai Zhang,Xupin Zhuang,Sisi Li,Lei Shi,Weimin Kang,Bowen Cheng,Xianlin Xu
In this work, a nylon 6 nanofibrous membrane was prepared via solution blowing technology and followed hot-press as scaffold for nanofiltration. The structure and properties of the hot-pressed nylon 6 nanofibrous membrane (HNM) were studied the effect of hot-pressing parameters and areal densities. Then an ultra-thin polyamide (PA) active layer was prepared by interfacial polymerization on HNM. The effects of nanofibrous scaffolds on the surface properties of ultra-thin nanofiltration membranes and their filtration performance were studied. Results showed that the nylon 6 nanofibers prepared at a concentration of 15 wt % had a good morphology and diameter distribution and the nanofibers were stacked more tightly and significantly reduced in diameter after hot pressing at 180 °C under the pressure of 15 MPa for 10 s. When the porous scaffold was prepared, HNM with an areal density of 9.4 and 14.1 g/m2has a better apparent structure, a smaller pore size, a higher porosity and a greater strength. At the same time, different areal densities of HNM have an important influence on the preparation and properties of nanofiltration membranes. With the increase of areal density, the uniformity of HNM increased while their surface roughness and pore size decreased, which is beneficial to the establishment of PA barrier layer. With areal density of 9.4 and 14.1 g/m2, the as-prepared nanofiltration membrane has a smoother surface and more outstanding filtration performance. The pure water flux is 13.1 L m−2h−1and the filtration efficiencies for NaCl and Na2SO4are 81.3% and 85.1%, respectively.Keywords:solution blowing;nylon 6 nanofibrous membrane;scaffold;nanofiltration
研究领域:
材料科学
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纳米技术
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膜技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2013
·Vol. 35
·期 4
·627-635
·
IF 1.482
Lei Xia,Baoqing Shentu,Zhixue Weng
The effect of dendrimer-like polyamidoamine grafted attapulgite (ATP-PAMAM) on the microstructure and morphology of Nylon-6 (PA6) was investigated. The ATP-PAMAM nanoparticles were prepared by treating attapulgite (ATP) with heat and acid followed by grafting with polyamidoamine (PAMAM) molecules, which was confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and dispersion state in formic acid. The X-ray diffraction (XRD) analysis result indicated that the grafting modification was occurred on the surface of fibrous crystals and did not shift the crystal structure of ATP. PA6/ATP-PAMAM (G 2.0 ) nanocomposites with different modified ATP content were prepared by melt compounding in a twin screw extruder. XRD measurements suggested that the intensity of diffraction peak of α crystalline form of PA6 decreased gradually as the inclusion of ATP-PAMAM(G 2.0 ) into the PA6 matrix, while that of γ crystalline form increased gradually. The results of molau experiment and scanning electron microscopy (SEM) observation showed not only a uniform dispersion of ATP-PAMAM(G 2.0 ) in the PA6 matrix but also a strong interfacial adhesion between them. Mechanical investigation (by tensile test) showed an obvious improvement in the presence of surface modified ATP. POLYM. COMPOS., 35:627–635, 2014. © 2013 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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Yijian Wu,Hui Zhang,Baoqing Shentu,Zhixue Weng
Organo-montmorillonite (OMMT) was introduced into SEBS-g-MA toughened poly(phenylene oxide)/polyamide-6 (PPO/PA6) blends simply by melt extrusion. The effects of OMMT on morphology, rheology, and mechanical behaviors of toughened PPO/PA6 nanocomposites were studied by scanning electron microscope, transmission electron microscope, capillary rheometer and mechanical tests. The addition of OMMT could decrease the size of dispersed PPO domains in PA6 matrix and melt viscosity of the toughened PPO/PA6 nanocomposites. Besides, exfoliated OMMT also brought significant improvement of tensile properties and heat deflection temperature (HDT), simultaneously. For nanocomposites with exfoliated OMMT, OMMT induced more core–shell toughening particles with the optimized size, and thus, elastomer-OMMT synergistic toughening was achieved in the PPO/PA6 nanocomposites. Consequently, PPO/PA6 nanocomposites with high tensile strength, excellent impact performance, improved HDT, and good processability were obtained.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2019
·
IF 6.282
Tao Zhang,Yue Xu,Hongfu Li,Boming Zhang
In this study, the effect of carbon fiber (CF) surface chemistry and grafting of nano-SiO 2 on CF surface with respect to the interfacial adhesion of CF-reinforced nylon 6 composites was investigated. CFs were oxidized and reacted with poly(oxypropylene) diamines to modify the surface chemistry. The oxidized CFs were modified with 3-aminopropyltriethoxysilane and then grafted with SiO 2 nanoparticles. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microcopy (SEM), and atomic force microscopy (AFM) were used to characterize the chemistry and topographies of the CF surface. The transverse fiber bundle strength of CF oxidized and grafted nano-SiO 2 increased to 31.92 MPa and 39.35 MPa, respectively, from 12.57 MPa for untreated CF. The results indicated that the reaction between the carboxyl group and nylon 6 led to chemical bonding at the interface and it meanwhile was strengthened and toughened by uniformly distributed SiO 2 nanoparticles on the CF surface.
研究领域:
材料科学
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
SENSORS
·
2014
·Vol. 14
·期 11
·21453-21465
·
IF 2.048
Zengyuan Pang,Jiapeng Fu,Pengfei Lv,Fenglin Huang,Qufu Wei
Camphor sulfonic acid (CSA)-doped polyamide 6/polyaniline (PA6/PANI) composite nanofibers were fabricated usingin situpolymerization of aniline under different CSA concentrations (0.02, 0.04, 0.06, 0.08 and 0.10 M) with electrospun PA6 nanofibers as templates. The structural, morphological and ammonia sensing properties of the prepared composite nanofibers were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), four-point probe techniques, X-ray diffraction (XRD) and a home-made gas sensing test system. All the results indicated that the CSA concentration had a great influence on the sensing properties of CSA-doped PA6/PANI composite nanofibers. The composite nanofibers doped with 0.02 M CSA showed the best ammonia sensing properties, with a significant sensitivity toward ammonia (NH3) at room temperature, superior to that of the composite nanofibers doped with 0.04–0.10 mol/L CSA. It was found that for high concentrations of CSA, the number of PANI–H+reacted with NH3would not make up a high proportion of all PANI–H+within certain limits. As a result, within a certain range even though higher CSA-doped PA6/PANI nanofibers had better conductivity, their ammonia sensing performance would degrade.Keywords:polyaniline;camphor sulfonic acid;polyamide 6;ammonia;gas sensor
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Kai-di Cui,Bei-xing Li,Xue-ping Huang,Lei-ming He,Da-xia Zhang,Wei Mu,Feng Liu
Sustained-release profile is an important component in the quality control of microcapsules. In the current study, we propose a reliable, convenient, and versatile strategy to assess the controlled-release performance of MCs under artificial, simulated conditions. Dissolution tests were performed using an experimental device equipped with syringe filters. The optimum experimental conditions utilized 80% v/v methanol (3 ml) as a release medium at each sampling point, Nylon 6 filters (13 mm diameter, 0.22 μm pore size) as diffusion barriers, and a sampling regime based on predetermined changed intervals. Validation tests demonstrated that this strategy possessed favorable universality for three wall materials (polyurea, polyurethane and urea-formaldehyde) and three core materials (phoxim, pyraclostrobin and clomazone), as all sampling points had standard errors below 3.4%. Our proposed method also showed apparent advantages in experimental precision and the demand for a release medium compared with dynamic dialysis.
研究领域:
药剂学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2018
·Vol. 10
·期 8
·872
·
IF 2.935
Yongxian Zhao,Chen Ma,Shijie Cheng,Wei Xu,Yuejuan Du,Yansong Bao,Zuojie Xiao
Maleic anhydride (MAH)–divinyl benzene (DVB) multi-monomer melt-grafting onto isotactic polybutene-1 (iPB-1) was carried out in a torque rheometer. The effects of dicumyl peroxide (DCP), MAH, and DVB concentrations, and temperature, on the reaction, were investigated. The optimized conditions were 170 °C, DVB/MAH = 4:6 (mass ratio). DVB as a comonomer enhanced the grafting degree (Gd) and grafting efficiency (Ge) of iPB-g-MAH better than styrene. The initiator DCP had little effect on Gd as its concentration over 0.2 phr, but the grafts’ melt flow rate (MFR) increased significantly, and relative molecular weight decreased remarkably with increased DCP concentration. With increasing Gd, the contact angle of grafts with water decreased, and there was a larger crystallization rate. The study of iPB-1 and iPB-g-MAH (Gd = 1.5%)-modified polyamide 6 (PA6) showed that iPB-g-MAH had an obviously toughening effect on PA6. With increasing iPB-g-MAH concentration, the blends of impact strength and elongation at break increased obviously, tensile strength decreased slightly, and MFR decreased prominently, which greatly slowed the processing degradation of PA6. The properties of iPB-1/PA6 blends deteriorated. Both DSC curves and SEM micrographs confirmed that PA6/iPB-g-MAH blends had much better compatibility than PA6/iPB. The reason was that the anhydride group in iPB-g-MAH reacted with amide group in PA6 to improve the compatibility between two phases, and iPB-g-MAH is an excellent modifier for PA6.Keywords:isotactic polybutene-1;maleic anhydride;divinyl benzene;polyamide 6;modification
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
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2017
·
IF 1.174
Chunxi Qin,Jie Tang,Fenglei Bi,Zhenhao Xi,Ling Zhao
The solid–liquid extraction process of nylon 6 to eliminate small molecules, i.e. , caprolactam (CL), cyclic dimers (CD) and cyclic trimers (CT), is investigated in detail by both batch extraction experiments and numerical simulations. In the batch extraction experiments, due to the small molecules attaching to the polymeric surface, the basic physical mechanism shifts from surface diffusion to internal diffusion as the extraction proceeded. The experimental data are well reproduced by a diffusion model consisting of two distinct steps, characterized as surface diffusion and internal diffusion. Furthermore, based on the established mass transfer mechanism and diffusion model of the two distinct steps, the equilibrium constants and internal diffusion coefficients of CL, CD and CT are acquired. An industrial countercurrent extraction tower is further simulated. It is found that the extraction efficiency of CL can be significantly improved by increasing the temperature at the bottom portion of the tower. The elimination of CD, which can be greatly promoted by a high-concentration CL-water solution, is controlled by mass transfer resistance, whereas the removal of CL is mainly affected by the equilibrium.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Feng Liu,Chunxiang Lu,Tongqing Sun
The poor wetting and spreading performances of waterborne polyurethane dispersion (WPUD) on carbon fiber (CF) surface limited its application in regulating the interfacial properties of CF reinforced polyamide 6 (PA6) composites. Unlike previous studies, this work diversified into improving the film-forming property of WPUD on CF surface. Two novel WPUD sizing agents named WPUD-Y1 and WPUD-F1 were synthesized by introducing block polyether and organic fluorine into the molecular chain. Results showed that surface energies of the elaborately designed WPUD-Y1 (35.5 mN/m) and WPUD-F1 (32.7 mN/m) were significantly lower than that of ordinary WPUD (40–55 mN/m). Especially, both sizings formed a complete and uniform film on CF surface. Interfacial shear strength (IFSS) analysis from micro-droplet test showed that sizing relieved the thermal residual stress at composite interphase by over 40 %, at the cost of reducing its interfacial strength by 20 %. More importantly, although sizing had not enhanced interfacial adhesion, the IFSS values between the sized CF and PA6 were still 20 % higher than the maximum interlaminar shear strength (ILSS) values reported in literatures.
研究领域:
材料科学
·
复合材料
✓ 已验证
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2025
·
IF 9.8
Yining Wang,Yuxi Pan,Mingguang Zhang,Yu Deng,Zhimin Wang,Xigao Jian,Yousi Chen
Grounded in the principle of “like dissolves like”, the development of water-soluble sizing agents characterized by matrix-like structures has emerged as a focal point of research within the interface domain. Nevertheless, the reliance exclusively on the entanglement forces between the sizing agent and the matrix is deemed inadequate. In this study, a novel water-soluble dual-component sizing agent tailored for the nylon 6 (PA6) resin matrix has been developed. By leveraging the self-emulsifying and water-soluble properties of sodium lignosulfonate (SL) and polyamic acid (PAA), these components are concurrently introduced onto the fiber surface. Following treatment, a distinct interfacial region is established on the fiber surface as a result of their interactions. Exploiting their intrinsic differences at processing temperatures facilitates differential wetting of the matrix resin on the fiber surface, consequently resulting in the formation of a “mechanical interlocking” structure between the fiber and the matrix. The findings reveal that the flexural strength and interlaminar shear strength of the modified CF/PA6 composites achieved values of 977.8 MPa and 74.1 MPa, corresponding to enhancements of 27.4 % and 28.8 %, respectively, when compared to their unmodified counterparts. This innovative sizing agent not only significantly enhances interfacial adhesion but also confers high added-value potential to lignin-derived materials, a factor that is essential for future sustainable development.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Zhujun Wang,Qian Li,Zheming Chen,Jinfeng Liu,Tengfei Liu,Huayi Li,Shuirong Zheng
To improve the effective thermal conductivity of hexagonal boron nitride (h-BN) in polymer matrix, surface modification upon it could be a usual and efficient method. Boron nitride nanosheets (BNNSs) were abundantly decorated by amino groups via a two-step reaction. The prehydroxylation of BNNSs in a concentrated base environment could increase the active reaction sites on the surface of BNNSs, so that aniline carbocations produced by the hydrolysis of the diazonium salt were utilized to achieve a high grafting content of aniline groups onto the surface of modified BNNSs (A-BNNSs). During melt blending, chemical reactions between A-BNNSs and the carboxyl groups of PA6 chains benefited the interfacial force between A-BNNSs and PA6 matrix; thus, the distribution of A-BNNSs in PA6 matrix was enhanced. Consequently, the prepared PA6/A-BNNSs nanocomposites had improved thermal conductivity, better thermal stability, and enhanced mechanical properties compared with the PA6/BNNSs nanocomposites at the same filler content. In particular, as for PA6/A-BNNSs nanocomposites with 20 wt % filler loading, its thermal conductivity was 2.886 W·m–1·K–1, nearly 10 times that of pure PA6, and its initial decomposition temperature was nearly 100 °C higher than that of pure PA6, which would be a popular candidate for the thermal conductivity field.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 11
·2763-2774
·
IF 2.578
Shuo Fan,Yanlu Sun,Xueli Wang,Jianyong Yu,Dequn Wu,Faxue Li
A novel organic-inorganic flame retardant (SP-APP) was first designed by coating ammonium polyphosphate (APP) with Schiff base-containing branched polysiloxane via ion exchange reaction and dehydration-condensation. High water resistance and charring capacity of the SP-APP greatly overcame the poor water resistance of APP and endowed polyamide 6 (PA6) with excellent flame retardancy and anti-dripping. The prepared PA6/SP-APP composite with 12 wt% of SP-APP reached the highest limited oxygen index (LOI) of 32.5% and passed V-0 rating of UL-94 test with non-dripping, while PA6 and PA6/APP with 12 wt% of APP failed to pass the UL-94 test. A sharp reduction of 50.9% in peak heat release rate (PHRR) and 29.4% in total heat release (THR) was found for PA6/SP-APP in contrast with PA6. The working mechanism of SP-APP in enhancing the flame retardancy of PA6 was also explored intensively and the synergistic effects of catalytic degradation of APP, self-crosslinking behavior of Schiff base structure and thermo-oxidative degradation of branched polysiloxane contributed to the improvement of flame retardancy of PA6/SP-APP.
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）