POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Yueyue Yu,Shan Tang,Dong Feng,Yuhui Xie,Feng Wu,Delong Xie,Yi Mei,Hao Huang
The development of flame-retardant polymer materials play a vital role in reducing fire hazards and protecting both lives and property. Black phosphorus (BP) is an extremely promising flame retardant since its synergistic flame retardancy with different modifiers. Nevertheless, the issue of unven dispersion within the polymer matrix has severely restricted its practical applications. Herein, BP nanosheets functionalized with ionic liquid (IL-BP) were prepared and then compounding with EVA to improve the mechanical and the flame-retardant properties of EVA matrix. The results demonstrated enhanced compatibility of IL-BP nanosheets within the EVA matrix, leading to the 1.5 %IL-BP/EVA composite displayed a 25 % and 9.6 % increase in tensile strength and elongation at break, respectively. Remarkably, the flammability test results demonstrated that the 1.5 %IL-BP/EVA sample featured a significant decrease of 18.1 % and 21.5 % in total heat release (THR) and peak heat release rate (PHRR), respectively. Meanwhile, the composite also achieved a V-0 rating in UL-94 test and demonstrated superior resistance to melt dripping. The flame-retardant mechanisms of IL-BP/EVA composites in both gas phase and condensed phase were studied. This work provides a promising strategy to design synergetic flame retardants that simultaneously enhanced the fire safety and mechanical properties of EVA.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2021
·
IF 6.617
Ping Wang,Li Yang,Yiyang Zhou,Shang Gao,Tian Cao,Shaojie Feng,Pei Xu,Yunsheng Ding
Hydroxylated BaTiO 3 (BT-OH) and multiwalled carbon nanotubes (MWCNTs) were incorporated into polyamide (PA) and ethylene-vinyl-acetate-glycidyl methacrylate random terpolymer (EVA-GMA) blends by melting-blend and hot-pressing method. Compared with PA/EVA-GMA/C nanocomposites, PA/EVA-GMA/20B/C nanocomposites exhibited higher dielectric permittivity, originating from the high dielectric constant of BT-OH and remarkable interface polarization effect between polymer and two types of nanofillers. Moreover, the nonconducting BT-OH can prevent the conductive path of MWCNTs and support low loss tangent. The dielectric constant of PA/EVA-GMA/20B/4C was 31.5 at 100 Hz, approximately three times higher than that of PA/EVA-GMA, and the loss factor was only 0.18, close to that of PA/EVA-GMA. PA/EVA-GMA/20B/4C exhibited tensile strength and elongation at break of 27.7 MPa and 67.9%, respectively. The mechanical and dielectric properties of PA/EVA-GMA/20B/4C were synergistically improved.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2025
·
IF 7.7
Liqiang Shang,Hao Zheng,Jiali Chen,Yiming Ren,Wenge Zheng,Bin Shen
Construction of conductive polymer composites (CPCs) for green electromagnetic interference (EMI) shielding with efficient shielding effectiveness (SE) but low EM reflection is urgently needed. Though the introduction of cellular or gradient structures can effectively reduce EM reflection, most current methods for preparing gradient CPC foams are relatively complex and lack sufficient applicability for large-scale production. Herein, we demonstrate the convenient fabrication of gradient-structured EVA/carbon nanostructure (CNS) foams through chemical foaming of thermally molded EVA/CNS composites with gradient CNS construction. Compared to uniform EVA/CNS foams, lower R coefficient with an effective EMI SE of >20 dB was obtained for gradient EVA/CNS foams with 3 phr CNS, accompanied by an average green shielding index (g s ) of ∼2.8. This study provides a more feasible two-step process of thermal press molding and chemical foaming for mass manufacturing of gradient CPC foams with effective green EMI shielding characteristics.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Mo Zou,Jingzhi Chen,Zhaoyang Wei,Weiwei Lei,Jun You,Jie Liu,Qunchao Zhang,Dean Shi
Core-shell particles with rigid core and soft rubber shell have been proven to be effective in strengthening and toughening polymers simultaneously when the rubber shell thickness is controlled within a critical range. However, the critical value of the so-called thickness-to-diameter ratio τ (the ratio of the rubber shell thickness to the rigid core diameter) obtained in the previous work are all from polymer blends containing core–shell particles with monodispersed particle size. Does the critical τ value still exist in the core–shell toughening system with polydisperse particle sizes? Is it possible to produce core–shell particles with polydisperse particle sizes but the same τ value? In this paper, the post-emulsification method is first reported to prepare core–shell particles with polydisperse SiO 2 particles as the rigid core and ethylene–vinyl acetate copolymer grafted maleic anhydride (EVA- g -MAH) as the rubber shell, in which the thickness of the rubber shell can be well controlled and tuned via varying the feeding weight ratio of SiO 2 and EVA- g -MAH. The τ value is only determined by the weight ratio of SiO 2 and rubber, and has nothing to do with the SiO 2 particle size. A series of polyamide 6 (PA6)/SiO 2 @EVA core–shell toughening systems are prepared via melt blending process. It is proved the existence of the critical τ value ( τ cbd ) above which brittle-ductile transition happens in the core–shell toughening system with polydisperse core–shell particle sizes. The value of τ cbd is 0.069 in PA6/SiO 2 @EVA core–shell toughening system.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
DOI
高影响因子
POLYMER TESTING
·
2021
·
IF 4.282
Xuechao Wang,Haibing Wei,Hongmei Xu,Xueliang Li,Guobing Zhang,Sheng Cheng,Chenxi Wang,Gang Ruan,Yiyang Zhou,Yunsheng Ding
A repellent for rats named DC has been successfully synthesized from natural capsaicin and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) via a one-pot procedure. The chemical structure of obtained DC is confirmed by Fourier transform infrared (FTIR), Raman and nuclear magnetic resonance (NMR). Then DC was incorporated into ethylene vinyl acetate copolymer (EVA) by blending, to endow EVA with rat proof property and present the advantage of non-lethal. The influence of DC on the structure and properties of EVA is investigated systematically by theoretical calculations and various measurements. Thermogravimetric analysis (TGA) reveals that the incorporation of 4 wt% DC into EVA can significantly enhance the char residue yield from 2.80 wt% to 6.84 wt%. In addition, limiting oxygen index (LOI) and the char residues analysis suggest that DC could facilitate the formation of char layers, resulting in the improvement of synergistic flame retardancy for EVA/DC compounds. This work provided novel insights into the preparation of highly efficient non-lethal repellent for rats and its potential application for polymer materials.
研究领域:
材料科学
·
化学合成
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CRYSTAL GROWTH
·
2021
·
IF 1.797
Decao Ma,Lei Wang,Peiran Tong,Yanyan Zhang,Xin Jiang,Hengbin Mao,Tingting Xu,Bingbing Fan,Gang Shao,Wen Liu,Mingliang Li,Jinpeng Zhu,Hailong Wang,Hongliang Xu,Rui Zhang,Hongxia Lu
CsPbX 3 (X = Cl, Br, I) all-inorganic perovskite quantum dots have attracted extensive attention from researchers recently. However, the further development is confined by serious stability problems. In this work, the CsPbBr 3 QDs@SiO 2 /EVA films were prepared by supersaturated recrystallization, and SEM, EDS, XRD, FT-IR and PL were used to study microstructure, phase composition, and optical properties. Results show that during the preparation process, the amounts of precursor added would affect the fluorescence emission intensity of materials. The preparation method of films is simple, easy to operate, low cost, and beneficial to commercial large-scale production. In a typical synthesis, PbBr 2 and CsBr are dissolved in DMF, and then oleic acid (OA) and oleylamine (OAm) as ligands are added to stabilize the DMF−PbBr 2 −CsBr precursor solution. When the addition of TEOS is 0.06 mL, the PL peak strength of prepared films is higher and the thickness of CsPbBr 3 QDs@SiO 2 /EVA films is about 100 μm and flexible enough to be bent. At room temperature, the retention of fluorescence intensity of films is 67.4% after 30 d in the air, the retention is 63.6% after 40 h in the water, and the retention is 72.1% after 40 h under the UV light. EVA resins and SiO 2 coating can effectively isolate the contact between quantum dots and moisture and delay the intrusion of oxygen, which significantly improves the stability of pure quantum dots.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yufeng Zhou,Jing Ding,Ze Wang,Yao Tong,Xiaojuan Liang,Juan Du,Wei Xia,Zhengzheng Liu,Weidong Xiang
In recent years, perovskite nanocrystals (NCs) have been considered novel and potentially valuable optical gain materials that can generate relatively low thresholds and stable stimulated emissions in various external environments. Here, for the first time, an ethylene vinyl acetate copolymer (EVA) film-protected metal halide perovskite (Cs 4 PbBr 6 ) solid powder was successfully synthesized, and its photoluminescence quantum yield (PLQY) value was as high as 61%. In addition, because the Cs 4 PbBr 6 @EVA composite film has excellent optical gain performance, this work explored the optical gain of the Cs 4 PbBr 6 @EVA composite film under 800 nm femtosecond (fs) laser excitation. The experimental results show that the Cs 4 PbBr 6 @EVA composite film has a low threshold (0.89 mJ/cm 2 ) and stable stimulated emission and generates amplified spontaneous emissions (ASEs) at 544 nm. In addition, the application of Cs 4 PbBr 6 @EVA composite film in the field of white light-emitting diodes (WLEDs) has also been studied. The color gamut of this Cs 4 PbBr 6 @EVA composite film is as high as 124.7% of the National Television Standards Committee (NTSC) 1953 standard color gamut and covers 92.8% of the Rec. 2020 standard color gamut. This work proposes a simple method to solve the problem of the poor stability of perovskite solid powder, and the prepared Cs 4 PbBr 6 @EVA composite film shows significant promise in WLED and laser applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 5
·1183
·
IF 3.1
Ying Qiu,Caili Wang,Chunxue Zhao,Guoxin Yao,Zhixue Wang,Runquan Yang
As a common coal-based solid waste, fly ash is widely used in material filling. However, due to the high resistivity of fly ash itself, the antistatic performance of the filling material is poor. Therefore, antistatic composite powder was prepared by coating nano-sized antimony-doped tin oxide (ATO) on the surface of fly ash, and its preparation mechanism was discussed. The composite powders were characterized by SEM, EDS, XRD and FTIR. The results show that the interaction between SiO2and SnO2appears at the wave number of 727.12 cm−1, and the obvious SnO2crystal phase appears on the surface of fly ash. The volume resistivity of calcined fly ash is 1.72 × 1012Ω·cm, and the volume resistivity of ATO fly ash is reduced to 6 × 103Ω·cm. By analyzing the limiting oxygen index, melt index, tensile strength, elongation at break, cross-section morphology and surface electrical resistivity of EVA, it was found that the addition of antistatic powder to EVA can improve its antistatic performance without deteriorating the mechanical properties of EVA.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Xuewen Ning,Xin Song,Sheng Zhang,Yong Wang,Yujun Feng
Nanohybrid materials can significantly inhibit wax deposition and improve the fluidity of crude oil. However, the mechanisms behind wax resolving, crystal modification, and flow improving are still unclear owing to the complexity of crude oil. Here, we compared the effect of ethylene vinyl acetate (EVA) and nanohybrids composed of EVA and SiO2 nanoparticles on wax crystallization and rheological behavior of Shengli waxy oil. Differential scanning calorimetry results indicate that SiO2 nanoparticles boost the efficiency of EVA for reducing the wax appearance temperature of waxy crude oil. Thermo X-ray diffraction characterization demonstrates that EVA/SiO2 nanohybrids cut down the crystal index of waxes, with the grain size of crystal cells decreased in (006) and (200) but increased in (110) cross sections. Polarized optical microscopy imaging reveals that EVA can modify the morphology of wax crystals to suppress the formation of wax gel, and nanohybrids serve as nucleuses to adsorb asphaltenes and resins, restraining the appearance of wax crystals. The rheological test shows that nanohybrids outperform EVA in decreasing the viscosity, inflection point, and yield stress of waxy crude oil. These findings help the understanding of flow improving by nanohybrid materials and offer guidelines for designing the new generation of wax inhibitors for safe transportation and flow assurance of waxy crude oil.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 58
·36382-36391
·
IF 3.108
Xiaobin Lu,Hongguo Zhao,Chunhui Feng,Qian Chen,Zhao Zhang,Chunhua Yang,Xianru He,Xin Wang
In order to improve the compatibility of Fe3O4 particles with ethylene vinyl acetate copolymers (EVA) composite hot melt adhesives (HMAs), Fe3O4 magnetic particles were surface coated with polyvinyl acetate (PVAc). The PVAc-coated Fe3O4 modified EVA composite HMAs were characterized by SEM, DSC, XRD, optical contact angle measuring, infrared dichroism and parallel-plate rheometer measurements. The results showed that Fe3O4 particles were successfully coated by PVAc, leading to better dispersion of the particles in EVA composite HMAs. It was also found that the orientation structure, interfacial property and the flow properties of the modified HMAs were all changed, and the segment orientation degree and crystallinity of the modified EVA composite HMAs clearly increased with the increase of PVAc-coated Fe3O4 particles content. Importantly, the peel strength of the modified HMAs was further enhanced. For the modified HMAs with 15 phr (parts per hundred resins) of PVAc-coated Fe3O4 particles, the peel strength reached 6.6 kN m−1 and was increased by 247% compared with the unmodified HMAs.
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
·
2025
·
IF 9.8
Jinfeng Cai,Jinchuan Liu,Hangsheng Weng,Shuiyan Liu,Dezhi Zhu,Guanda Yang,Jian Liu,Li Zhou,Muchao Qu
In this study, a multilayer flexible composite membrane ( EVA/Ga@CF ) was developed by constructing a stable liquid metal conductive network on continuous carbon fiber fabrics. Mechanical testing revealed that EVA/Ga@CF achieved a tensile strength of 2.1 GPa and a Young's modulus of 12.6 GPa, confirming the critical role of liquid gallium in interfacial bridging and stress transfer. Self-healing evaluation showed that the water contact angle at scratched regions returned to its initial value within 120 s subjected to electrical stimulation. Electromagnetic performance tests indicated that EVA/Ga@CF maintained a total shielding effectiveness (SE-T) of approximately 35 dB across the X-band (8.2–12.4 GHz), achieving superior efficiency in both thickness-normalized and metal content-normalized metrics. Furthermore, the introduction of the continuous liquid gallium network significantly enhanced dielectric polarization and electromagnetic wave attenuation capabilities. Overall, this work proposes a new strategy for co-engineering liquid metals and high-strength carbon fiber frameworks, highlighting their potential for applications in high-performance flexible electronics and robotic exoskeleton systems.
研究领域:
材料科学
·
高分子复合材料
·
功能材料
·
柔性电子学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2021
·
IF 2.262
Jing Zhang,Hailin Yu,Yu Liang,Zhengnan Sun,Yang Liu,Guolin Jing
In this paper, the organic nano-sepiolite was modified to obtain highly dispersibility in the oil phase, and then, EVA (ethylene-vinyl acetate)/nano-sepiolite was prepared by melt blending. The effects of un-doped/doped different NPPDs oil samples on the pour point, gel point, viscosity, and yield value of Daqing crude oil were evaluated. The changes of wax crystal morphology at low temperature were observed by polarizing optical microscopy (POM). The results show that due to the heterogeneous nucleation mechanism and high dispersion in the oil phase, EVA/nano-sepiolite has a better effect on reducing pour point and makes EVA have a higher local concentration in the oil phase, which weakens the wax crystal structure, and greatly improved the low temperature rheology of Daqing crude oil. Compared with pure EVA, EVA/nano-sepiolite can further reduce the pour point, gel point, viscosity, and yield value of Daqing crude oil at the optimum additive concentration of 200 ppm. Among them, it can further reduce the pour point 2 °C and further reduce the gel point 0.93 °C; at 15 °C, the viscosity reduction rate was 20% and the yield value at 15 °C was reduced by 82%.
研究领域:
石油工程
·
材料科学
✓ 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）