Polymer Crystallization
·
2020
·Vol. 3
·期 3
·e10130
·
IF 0
Dachuan Ding,Jingjin Luo,Jie Wang,Zixin Yu,Yuanfu Tian,Jinqiang Tan,Zhiyuan Song,Qian Tao,Tao Hu,Chonggang Wu
Ionized polyamide (PA)-66 was successfully prepared at room-temperature using HCl (0.31 mol%) and CaCl 2 (2.3 mol%), respectively. The PA-66 ionenes, compared with the non-ionized PA-66, are used as a nucleator along with cholesteryl nonanoate (CN) as an active plasticizer to improve poly(bisphenol-A carbonate) (PC) crystallization. The results show the PA-66-HCl heterogeneously nucleates PC more effectively than the PA-66-CaCl 2 . The possible rationale is that the strong ion-dipole interactions (IDIs) of the PA-66-HCl remarkably boost the PC/PA-66-HCl interfacial compatibility, which results in the formation of considerably finer and denser PA-66-HCl crystals with significantly enhanced nucleation efficiency. However, owing to its higher ion content, the PA-66-CaCl 2 seems to have much stronger IDIs with PC that the resulting compatibility (i.e., thicker amorphous interlayers) dramatically inhibits PC crystallization.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
MATERIALS LETTERS
·
2017
·
IF 2.572
Jinshan Cao,Zhiqiang Cheng,Lijuan Kang,Yingying Zhang,Xiaodong Zhao,Shengzhe Zhao,Bo Gao
In this study, a novel polyethersulfone/polyamide 66 (PES/PA66) filtration media for airborne particles was prepared via electrospinning technique. SEM, TEM, FTIR, tensile tester, contact angle analyzer, thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC) were employed to characterize the morphology, the structural properties, mechanical properties, wettability and thermal properties, which indicated that the surface of the PES/PA66 composite nanofibers was smooth and uniform. As compared to pure PES membrane, the hydrophilicity of the PES/PA66 filtration membrane surface was better. Moreover, the composite membranes showed excellent filtration efficiency for the PM 0.3-5 , which was 99.999% for 0.3 μm particle.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Chanchal Kumar Kundu,Zhiwei Li,Xiaohong Li,Zhijun Zhang,Yuan Hu
A plant derived bio-macromolecule namely lignin (L) and a green phosphorus compound like phytic acid (PA) were functionalized with graphene oxide (GO) and subsequently, used to enhance the flame retardant properties of polyamide 66 (PA66) fabrics in a one pot deposition method. Meanwhile, we also considered pure phytic acid and one more bio-derived charring agent like chitosan (CS) to formulate a series of GO-based flame retardant finishing by altering the applied compounds in the formulation. The applied finishing with a minimum loading % (i.e., less than 10%) rarely altered the physical properties (i.e., color, handle and tensile strength , etc.) of treated textiles while provided enhanced thermal stability and added flame retardancy. Thus, a significant increase in limiting oxygen index (LOI) by 27% was received for the GO-lignin and GO-phytic acid modified fabric sample (i.e., PA66-A), indicating the supremacy of graphene-based compound. Furthermore, a substantial reduction in the peak heat release rate (pHRR) by 25% was also noticed for the fabric sample treated with GO-lignin, chitosan and phytic acid (i.e., PA66-D). Additionally, the as prepared finishing exhibited a considerable level of wash durability as a maximum reduction of pHRR by 17% was retained even after 5 washing cycles.
研究领域:
材料科学
·
纺织工程
·
生物化学
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产品关联
DOI
PubMed
高影响因子
Journal of Coatings Technology and Research
·
2023
·Vol. 20
·期 4
·1223-1234
·
IF 2.3
Kundu Chanchal Kumar,Li Zhiwei,Khan M. Azizur R.,Försth Michael,Das Oisik
Multi-functional textiles have received much attention in the technical textile field for their novel functionalities available in a single substrate. Polyamide 66 (PA66), being an engineering polymer with excellent physio-mechanical properties, exhibits immense possibilities to be developed as a multifunctional textile substrate. In this work, multi-functional polyamide 66 (PA66) textiles equipped with enhanced electro-conductive, hydrophilic and flame-retardant properties were developed via in situ polymerization of pyrrole monomer onto the PA66 fabric surfaces. Meanwhile, various formulations comprised of phytic acid (PA), chitosan (CS), graphene oxide (GO) and Na-metaborate (B) along with the pyrrole also experimented with a goal to study the contribution of each compound onto the desired properties and finally, to come up with a suitable formulation. Among these formulations, only pyrrole containing formulation (i.e., PA66-PPy) demonstrated a significant improvement in all three desired functionalities, namely a noteworthy escalation in electrical conductivity (i.e., about a 43 times increase compared to the pure PA66), a semi-hydrophilic surface (i.e., water contact angle value was lowered from 124.3– 49.9°) and a substantial reduction in the peak heat release rate by 45%. Meanwhile, the formulation comprising both the pyrrole and phytic acid made the polyamide surface a super-hydrophilic one, whereas other formulations exhibited potential efficacy in attaining better flame retardancy, especially in terms of limiting oxygen index (LOI) values, vertical flame test data and char yield%. Graphical abstract
研究领域:
纺织科学
·
材料科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Xue Ma,Xuefei Chen,Xiaohua Wang,Xiaohua Yang,Zengwen Yao,Houyong Yu,Yunyun Zhang
Polyamide 66 (PA66) has garnered significant attention due to its exceptional properties; unfortunately, its flammability is challenging. Adding flame retardants (FRs) is a primary approach to enhance PA66 flame retardancy. This study developed a highly flame-retardant PA66 composite film by adding corn-like functional nanohybrids (CNC/Al 2 O 3 ). Interestingly, CNC/Al 2 O 3 nanohybrids not only formed hydrogen bond interactions with PA66 but also improved crystallization properties as heterogeneous nucleating agents, resulting in the excellent mechanical properties of PA66 composite film. Remarkably, the incorporation of 3 wt% CNC/Al 2 O 3 nanohybrids into PA66 matrix contributed to increasing the LOI to 28.5 %. The pHRR, THR, and TSR were reduced obviously by 55.7 %, 15.3 %, and 65.2 %, respectively. The excellent flame retardancy of PA66 composite film was attributed to the forming of a compact carbon layer catalyzed by the CNC/Al 2 O 3 nanohybrids. Besides, the homogeneous distribution of CNC/Al 2 O 3 nanohybrids endowed the composite film with excellent heat insulation, and the heat insulation rate was up to 31.9 %. Thus, such PA66 composite films with excellent flame retardancy, heat insulation, and mechanical properties could meet the broader application requirements.
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
ACS Applied Nano Materials
·
2024
·
IF 5.3
Shuang Gao,Xiuyan Deng,Xiaoming Qi,Hongbo Dai,Shao-Yun Fu,Yaqin Fu
High-performance microwave absorption materials with broad electromagnetic absorption bandwidths and scalable architectures have been increasingly demanded in modern electric and telecommunications industries. Herein, we propose a flexible three-dimensional (3D) woven fabric with superior washability and electromagnetic-wave absorption capability using the nanoengineered carbon black (CB)-Fe3O4/polyamide-66 (PA-66) composite fibers that possess a unique core–sheath structure. Notably, the impedance matching and microwave attenuation of the proposed 3D fabric absorbers are realized by the dielectric–magnetic coupling effect of nanometer-sized CB and Fe3O4 nanoparticles within the constituent PA-66 fibers. The produced 3D fabrics showed superior mechanical properties with a tensile strength of 35 MPa, good softness with flexibility of drape coefficient up to 88.8%, and great air permeability with an air permeability of over 109 mm/s. At a weft density of 250 picks/10 cm, the fabric realized the best electromagnetic-wave absorption performance with a minimum reflection loss of −34.5 dB, owing to the good impedance-matched 3D orthogonal structures and integrated dielectric–magnetic fibrous networks of the 3D fabric. In particular, this performance could be well-maintained even after rinsing five times or folding to two layers. This study can provide a promising route to developing next-generation flexible electromagnetic absorption materials.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
POLYMER
·
2025
·
IF 4.5
Xiaohuan Bu,Wei Zhao,Xin Li,Wenjie Zhang,Yuancheng Zhang,Ge Shi,Yanjie He,Zhe Cui,Peng Fu,Xinchang Pang,Hong Wu,Xiaomeng Zhang,Minying Liu
Polyamide 66 (PA66) with less entangled structure, high crystallinity and excellent mechanical properties was fabricated in this work by direct solid-state polymerization (DSSP) method. The polymerization process and mechanism of DSSP were systematically investigated. Results demonstrate that DSSP is a transition process from salt crystal directly to polymer crystal, enabling the production of PA66 with a less entangled and highly crystalline structure. DSSP sample exhibits a crystallinity of 51.8% as tested by WAXD, and 59.7% when measured via DSC, surpassing the crystallinity of the majority of PA66 fibers. Furthermore, the sample achieves a maximum melting point of 271.7 °C. Correspondingly, mechanical properties and heat distortion temperature of DSSP sample are also improved. Therefore, this work enhances the in-depth understanding of polymerization mechanism of DSSP, and provides an efficient, scalable approach for fabricating polymers with less entanglement, high crystallinity, and exceptional performance characteristics.
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
CHEMOSPHERE
·
2023
·
IF 8.8
Kangkang Wang,Yuli Kou,Kefu Wang,Siqi Liang,Changyan Guo,Wei Wang,Yi Lu,Jide Wang
Microplastics (MPs) and dye pollutants are widespread in aquatic environments. Here, the adsorption characteristics of anionic dye methyl orange (MO) and cationic dye malachite green (MG) on polyamide 6 (PA6) and polyamide 66 (PA66) MPs were investigated, including kinetics, isotherm equilibrium and thermodynamics. The co-adsorption of MO and MG under different pH was also evaluated. The results reveal that the adsorption process of MO and MG is suitably expounded by a pseudo-second-order kinetic model. The process can be characterized by two stages: internal diffusion and external diffusion. The isothermal adsorption equilibrium of MO and MG can be effectively described using the Langmuir model, signifying monolayer adsorption. Furthermore, the thermodynamic results indicated that the adsorption was spontaneous with exothermic and endothermic properties, respectively. The results of binary systems reveal that MO dominates the adsorption at low pH (2–5), while MG dominates at high pH (8–10). Strong competitive adsorption was observed between MO and MG in neutral conditions (pH 6–8). The desorption experiments confirm that PA6 and PA66 could serve as potential carriers of MO and MG. The interaction between dyes and polyamide MPs is primarily mediated through hydrogen bonds and electrostatic attraction. The results reveal that PA6 formed more hydrogen bonds with the dyes, resulting in higher adsorption capacity than that of PA66. This difference can be attributed to the disparities in the synthesis process and polymerization method. Our study uncovered the adsorption mechanism of dye pollutants on PA6 and PA66, and provided a more comprehensive theoretical basis for the risk assessment concerning different types of polyamide MPs in aquatic environments.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2025
·
IF 7.4
Zixuan Zheng,John Lou Yao,Qiang Yao
To elucidate chemistry taking place during thermal degradation of polyamide 66 in the presence of phosphorus flame retardants and understand how commonly used phosphorus flame retardants achieve their flame retardancy, PA66 and a series of model compounds which include N,N'-dibutylhexanediamide, 1-butylazepane-2,7-dione and 1,8-diazacyclotetradecane-2,7‑dione have been subjected to thermal treatments together with melamine polyphosphate, aluminum diethylphosphinate or their combination respectively. Analyses of degradation products indicate that aluminum diethylphosphinate accelerates a cyclization reaction but does not change degradation mechanisms of polyamide 66 and its model compounds while melamine polyphosphate significantly shifts their degradation pathways to dehydration via a modified Hofmann elimination reaction which produces adiponitrile and water. Adiponitrile intumesces strongly when heated with polyphosphoric acid. Water hydrolyzes amides to amines, accompanied by the formation of amino-6-oxohexanoic acid which cyclizes to cyclopentanone. Water and amines together convert aluminum diethylphosphinate to diethylphosphinic acid. On the basis of the identification and transformation of reactive species, modes of flame retardant action of the combination of aluminum diethylphosphinate and melamine polyphosphate for PA66 have been proposed.
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
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2025
·
IF 2.7
Chenglong Wan,Like Hou,Qing Hu,Zihe Zhao,Yanxia Yang,Biao Zhao,Jianping Deng,Kai Pan
A series of thermoplastic polyamide elastomers (TPAEs) utilizing polyamide 66 (PA66) as the hard segment and amorphous diamine-sealed poly(oxypropylene)-poly(oxyethylene)-poly(oxypropylene) (PPO-PEO-PPO) with different molecular weight as the soft segment are synthesized through one-step melt polycondensation method. The chemical structure of TPAEs is confirmed by Fourier transform infrared spectroscopy (FT-IR) and hydrogen magnetic resonance spectroscopy ( 1 H-NMR). Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) results show that short-chain polyetheramine (Jeffamine-ED600) has good compatibility with PA66, which limits crystal growth and greatly reduced crystallinity, can be used as diluent to reduce the melting point of the material. However, the microphase separation of long-chain polyetheramine (Jeffamine-ED900) and PA66 leads to the increase of crystallinity, and the melting temperature does not decrease significantly with the increase of soft segment content. Mechanical properties tests show that all TPAEs exhibit good mechanical properties and excellent energy dissipation, with tensile strength up to 45 MPa and elongation at break up to 630%. The introduction of PEO unit results in the water absorption of TPAEs ranging from 25 to 65%, and the surface resistivity varying between 2.45 × 10⁹ and 1.6 × 10¹⁰ Ω, suggesting the synthesized TPAEs are suitable for use as permanent anti-static materials.
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 FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 32
·期 8
·3232-3241
·
IF 3.665
Wei Liu,Rui Shi,Zejiang Zhang,Mingqiang Yan,Xiaosui Chen,Yuyan Chen
Phytic acid (IP 6 ) as the major phosphorus-containing component of certain plants, such as cereal, oil plant, and bean possesses strong capability of coordinating with metal ion to form complex salt. In this study, low concentration IP 6 was utilized in combination with Al 3+ ion to in situ form insoluble Al 3+ -IP 6 complex salt on the surface of the fabric through coordination driven layer-by-layer deposition technology without high temperature cure step, which is an attempt to provide a facile bio-based flame retardant finishing to polyamide (PA) 66 fabric. Surface structure of the treated PA fabric has been analyzed via ATR-FTIR and SEM characterization. Effect of BLs' number on the flame retardancy and burning behavior of the treated sample has been examined by the limiting oxygen index (LOI) test, the vertical burning test, microcalorimetry, and thermogravimetric analysis. The results show that 20LBL PA fabric has the highest LOI value, highest residual char yield, and lowest THR value in all the samples and no melt dripping behavior could be detected during combustion of 20LBL PA fabric. Moreover, the insolubility of Al 3+ -IP 6 salt from the surface could promote the durability of the treated fabric after laundering procedure using water single. This is the first time to use coordination driven layer-by-layer deposition technology in the fabric's flame retardant finishing.
研究领域:
材料科学
·
纺织工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Qinan Hou,Yunhui Chen,Jiefei Wang,Meiqin Wu,Hou-Yong Yu,Xiaohua Wang
Polyamide 66 (PA66), a globally attractive high-performance plastic, is hindered by its poor fire resistance, which triggers excessive smoke and dripping. In this work, we introduce a novel halogen-free, thermal insulating flame-retardant for PA66, modified by cellulose nanocrystals (CNCs) with 3-aminopropyltriethoxysilane (APTES) and phosphoric acid (PA) to form a spider web-like nano composite CNC/A/P, by improving the thermal stability and inhibiting the droplet phenomenon of PA66. This high self-extinguishing flame retardant owns a 56.9 % residual carbon rate and the limiting oxygen index of 42.74 %. PA66-C15, incorporating 15 wt% CNC/A/P, significantly enhances PA66's flame retardancy, achieving a V-0 rating, and a rising LOI of 46.7 % from 21.6 %. Surprisingly, a 114.3 % temperature reduction (194.1 °C) under heating alcohol lamp were also observed in this PA66 composite, preserving superior tensile strength mechanical properties and thermal insulation. This study presents a promising, high-performance CNC-based flame-retardant material with excellent fire retardancy and mechanical 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
危险品化学品经营许可证（带存储）