POLYMER
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2020
·
IF 4.231
Changhong Lin,Huan Ge,Tianle Wang,Min Huang,Puyou Ying,Ping Zhang,Jianbo Wu,Shibin Ren,Vladimir Levchenko
The realization of recyclable materials is an urgent problem to be solved for extending practical applications in industry. Herein, a simple method was proposed to prepared the recyclable materials thorough dynamic reversible chemistry . In this work, we design the recyclable and self-healing polyurethane based on the thermoreversible dynamic Diels-Alder reaction. In addition, the Halloysite nanotubes (HNTs) were introduced into the system to improve the thermal properties, mechanical properties of polyurethane nanocomposites (PUDM/HNTs). The tensile tests showed that the HNTs can significantly improved the mechanical properties of nanocomposites. The healing efficiency above 90% on average was achieved which was determined by the recovery of breaking strength . Besides, the composites exhibited outstanding reprocessability via thermally induced. Therefore, Such excellent recyclable performance and self-healing ability give the polyurethane materials an opportunity to have great potential in the fields of save-energy, friendly-environment materials.
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高影响因子
POLYMER BULLETIN
·
2020
·Vol. 78
·期 8
·4403-4417
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IF 2.014
Zhu Yongfei,Li Peilin,Lin Runsheng,Su Junming
Both pyrogallol-furfurylamine-based and pyrogallol-aniline-based di-benzoxazines (PG-FA and PG-A) possess a free hydroxyl and latent catalytic characteristics. To decrease the ring-opening polymerization (ROP) temperature of benzoxazine based on phenol and 4,4′-diaminodiphenylmethane (P-DDM) and increase simultaneously thermal property of its polymer, PG-FA and PG-A as catalysts were introduced into P-DDM. DSC and FTIR tests were used to investigate the effect of PG-FA and PG-A on the ROP of P-DDM; DMA, FTIR and TGA were performed to study their effects on the hydrogen bonds and thermal property of the cured P-DDM (PP-DDM). The results indicate that the ROP temperature of P-DDM remarkably decreased with the incorporation of PG-FA and PG-A. FTIR and DMA results illustrate that the total amounts of hydrogen bonds in PP-DDM increased with the addition of PG-FA or PG-A; however, its fraction of –OH⋯N (intra) and O − ⋯ + HN (intra) hydrogen bonds decreased. The decrease in –OH⋯N hydrogen bonds made the cross-linked density of polybenzoxazine increase, resulting in that the thermal stability of PP-DDM enhanced with the introduction of PG-FA and PG-A.
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高影响因子
Colloid and Interface Science Communications
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2020
·
IF 2.831
Yuan Lei,Qiang Huang,Jibo Dou,Hongye Huang,Guang Yang,Fengjie Deng,Meiying Liu,Xiancai Li,Xiaoyong Zhang,Yen Wei
In this work, a novel adsorbent, sulfonic acid-functionalized carbon nanotubes (CNT-FA-SA) composite was synthesized by Diels-Alder (DA) chemistry and electrophilic substitution reaction . The adsorption of methylene blue (MB) onto CNT-FA-SA was systematically investigated. Based on the experimental data, MB was rapidly removed by CNT-FA-SA composite with maximum adsorption capacity of 236.55 mg/g under certain conditions. The non-linear relevant fitting result of Langmuir isotherm model fully estimates that the maximum adsorption capacity of monolayer can reach to 1584.22 mg/g. The adsorption kinetic is fitted better with the pseudo-second-order model than the pseudo-first-order kinetic model , and the isotherms were well described by Freundlich isotherm model. The data testified that the adsorption process is monitored by chemisorption and physical adsorption simultaneously. Relevant results also indicate that the adsorption occurred on heterogeneous multilayer surface. The parameters of pH and thermodynamic manifested that adsorption of MB onto CNT-FA-SA composites was pH-dependent and spontaneous endothermic reaction.
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高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2020
·Vol. 29
·期 3
·829-836
·
IF 2.572
Feng Libang,He Xia,Zhang Yunpeng,Qu Dongan,Chai Changsheng
Abstract Cracks in polymers can be healed by endowing materials with self-healing performance. Cracks in epoxy resins containing thermo-reversible Diels–Alder bonds (EP-DA) can be self-healed via different heat treatments. However, EP-DA exhibits the disadvantages of brittleness and poor impact resistance yet as that existed in the common epoxy resins, and which limits the application of thermo-reversible self-healing epoxy resins. Herein, thermoplastic polyurethane (TPU) was introduced into EP-DA for the purpose of reducing the brittleness and improving the impact resistance of EP-DA. Meanwhile, it was expected that the self-healing performance of EP-DA could not be affected evidently. Results showed that the impact resistance of EP-DA had been improved greatly as expected upon TPU modification. More importantly, instead of affecting the self-healing performance of EP-DA, the self-healing speed of EP-DA was accelerated evidently by the incorporation of TPU. On the other hand, the healing efficiency of EP-DA was also enhanced markedly. In fact, TPU-modified EP-DA was repaired by dual actions of thermo-reversible DA reaction and thermal movement of thermoplastic polymer chains. In addition, TPU-modified EP-DA could also be healed for many damage-repair cycles. Therefore, thermoplastic polyurethane played a triple role as toughening, accelerating and enhancing self-healing performance of thermo-reversible epoxy resins. Graphic Abstract Thermoplastic polyurethane (TPU) was introduced into thermo-reversible self-healing epoxy resins (EP-DA) successfully. As a result, the brittleness was reduced and the impact resistance of EP-DA was improved greatly. What’s more, instead of affecting the self-healing performance of EP-DA, the self-healing speed of EP-DA was accelerated evidently while the self-healing efficiency of EP-DA was enhanced markedly. Therefore, TPU played a triple role as toughening, accelerating and enhancing self-healing performance of thermo-reversible epoxy resins.
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高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2020
·
IF 7.094
Ting Wang,Wan-Cheng Yu,Wen-Jin Sun,Li-Chuan Jia,Jie-Feng Gao,Jian-Hua Tang,Hai-Jun Su,Ding-Xiang Yan,Zhong-Ming Li
The development of high electromagnetic interference (EMI) shielding composites is significant to practical application of electronic equipment. Nevertheless, there still remains a challenge in achieving durable EMI shielding effectiveness (EMI SE) when the EMI shielding materials suffers external mechanical damage or other diverse harsh circumstances. Herein, a healable EMI shielding composite was facilely developed, with dynamic crosslinking polyurethane holding Diels–Alder bonds (PUDA) as substrate and carbon nanotube (CNT) as electrical fillers. Segregated conductive networks with CNT selectively distributed among the interfaces of PUDA regions were constructed, endowing the CNT@PUDA composite with high EMI SE of 41.2 dB (X-band) at 7.0 wt% CNT loading. Thanks to the reversible Diels–Alder reaction, the CNT@PUDA composites can be repaired effectively and repetitively by heating or subjecting DC electricity. The EMI SE of cracked composite with 5.0 wt% CNT can recover from 17.1 to 33.8 dB (96% retention in comparison to original 35.5 dB) even after repeated cutting/healing process for three times, thanks to the reconstructed segregated CNT networks with the help of healable PUDA domains. The splendid mechanical properties with high healing efficiency of 91% further ensure the reliable EMI SE. The construction of DA dynamic bonds and segregated conductive network in our study offers meaningful guidance to practical construction and development of healable EMI shielding facility.
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高影响因子
GREEN CHEMISTRY
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2020
·Vol. 23
·期 1
·501-510
·
IF 9.48
Hafezeh Nabipour,Xin Wang,Lei Song,Yuan Hu
With the growing awareness of global warming and depletion of petroleum resources, the development of bio-based epoxy thermosets as an alternative to petroleum-based diglycidyl ether of bisphenol A (DGEBA) epoxy thermosets has generated extensive interest over the past decade. However, most of the bio-based epoxy thermosets studied to date are bio-based epoxy monomers or bio-based curing agents. In order to increase the biomass content in the resultant epoxy thermoset as high as possible, it is desirable to fabricate fully bio-based epoxy thermosets. In this study, we synthesized a bio-based epoxy monomer (SA-GA-EP) from syringaldehyde, as well as a bio-based curing agent (DIFFA) from furfurylamine. The fully bio-based epoxy thermoset was obtained through curing SA-GA-EP by DIFFA, while the commercial DGEBA epoxy thermoset was cured by 4,4′-diaminodiphenylmethane (DDM) as a contrast sample. The glass transition temperature (Tg) of the cured SA-GA-EP/DIFFA thermoset was as high as 204 °C, which was much higher than that of the DGEBA/DDM thermoset (143 °C). The tensile strength and elongation at break of SA-GA-EP/DIFFA were 57.4 MPa and 2.9%, respectively, which were comparable to those of DGEBA/DDM. Additionally, the cured SA-GA-EP/DIFFA thermoset displayed excellent intrinsic flame retardancy with UL-94 V-0 classification and a relatively high limiting oxygen index of 40.0%. The results of the cone calorimetry test also manifested that the peak heat release rate, the total heat release and the smoke production rate of SA-GA-EP/DIFFA significantly declined by 85%, 86% and 38%, respectively, compared to those of DGEBA/DDM. Moreover, bio-based epoxy exhibited antibacterial activities against Gram-positive S. aureus. Owing to these outstanding performances (including mechanical strength and modulus, high Tg, intrinsic flame resistance and antibacterial properties), this fully bio-based epoxy thermoset is a green and promising substitute for DGEBA-based thermoset in high performance fire safe applications.
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JOURNAL OF MOLECULAR LIQUIDS
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2020
·
IF 5.065
Linru Guo,Yanzhu Liu,Jibo Dou,Qiang Huang,Yuan Lei,Junyu Chen,Yuanqing Wen,Yongxiu Li,Xiaoyong Zhang,Yen Wei
The removal of environmental pollutants through adsorption by nanomaterials or nanocomposites has attracted great attention over the past few decades. In this work, a novel strategy that combined with Diels-Alder (DA) and multicomponent reactions has been developed to fabricate carbon nanotubes (CNT) based polymer composites and their potential utilization for removal of rare earth ions from wastewater. First, the amino groups were introduced on the CNT through the DA reaction between CNT and furfurylamine. The obtained amino group-terminating CNT composites (named as CNT-FFA) were further conjugated with the polymers through Kabachnik–Fields (KF) reaction. To evidence the successful fabrication of these CNT based polymer composites, a variety of characterization methods, such as Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS), were used to measure the chemical structure, compositions and thermal stability of CNT based polymer composites. Furthermore, a series of adsorption experiments were implemented to explore the influence of contact time, temperature, initial concentration and pH for adsorption behavior . The results demonstrated that the adsorption capability of resultant CNT based composites (CNT-FFA-PAA) towards Eu 3+ ions is about 130.8 mg g −1 , which is much greater than that of pristine CNT (46.67 mg g −1 ). The above results demonstrated that the method described in this work is a facile and effective tool for fabrication of functional CNT polymer composites, which possess promising prospects for environmental adsorption applications. More importantly, this method in this work could be generally applied in the surface modification of other materials for various applications.
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高影响因子
COMPOSITES PART B-ENGINEERING
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2020
·
IF 7.635
Ting Wang,Wan-Cheng Yu,Chang-Ge Zhou,Wen-Jin Sun,Yun-Peng Zhang,Li-Chuan Jia,Jie-Feng Gao,Kun Dai,Ding-Xiang Yan,Zhong-Ming Li
Electromagnetic interference (EMI) shielding composites are inevitably damaged in the long-term usage which would affect the regular operation of the devices. Hence, the demand for materials with healable and reliable EMI shielding performance has increased. Here, a flexible conductive composite owning both self–healing and EMI shielding functions is facilely developed, with carbon nanotubes (CNTs) as conductive filler and dynamically crosslinked polyurethane bearing Diels–Alder bonds (PUDA) as polymer matrix . The PUDA/CNT composite shows a high EMI shielding effectiveness (EMI SE) of 30.7 dB at 5.0 wt% CNT loading in the range of X-band (8.2–12.4 GHz). And the EMI SE can recover from 16.8 dB for damaged state to 29.8 dB after three times cut/healing cycles, revealing excellent EMI SE retention of 97.1%. The PUDA/CNT composite also exhibits healable tensile properties with an elongation at break up to 571% ± 31% at 2.0 wt% CNT content and self-healing efficiency of 89.2% after the repeatable healing. This work demonstrates a healable EMI shielding composite, which ensures the reliability and long-time use under harsh conditions.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 25
·11325-11338
·
IF 3.553
Cao Ying,Zhang Jiatian,Zhang Dandan,Lv Yan,Li Jie,Xu Yiting,He Kaibin,Chen Guorong,Yuan Conghui,Zeng Birong,Dai Lizong
Hexagonal boron nitride (hBN), as one of the two-dimensional (2D) materials, possesses many excellent properties like others. Herein, we report a novel self-healing epoxy filled with hBN. High compatibility between hBN and the epoxy matrix was obtained by the modification of hBN with silane coupling agent (Mi-Si). At the meantime, excellent self-healing behavior was achieved by retro Diels–Alder (r-DA) reaction between the maleimide functional group in the modified hBN (m-hBN-OH) and the added furfurylamine. Besides, the inadequate curing of epoxy led to the glass transition temperature (Tg), which is also seemed as the transition temperature for the shape memory of the epoxy, below the r-DA reaction temperature, and endowed the system with the shape memory-assisted self-healing properties. The m-hBN-OH was characterized by Fourier transform infrared spectra, nuclear magnetic resonance ( 1 H-NMR) spectra, X-ray diffraction experiments, X-ray photoelectron spectroscopy measurements and so on. The new m-hBN-OH modifier was prepared with the optimized Mi-Si/hBN-OH weight ratio of 3.0, which could both improve the thermal property and achieve better thermal conductivity. This designed m-hBN-OH/epoxy could actually show ideal self-healing properties due to the shape memory-assisted self-healing effect. The thermal conductivity of the neat epoxy resin and the m-hBN-OH/epoxy was 0.2156 W m −1 K −1 and 0.4358 W m −1 K −1 , respectively. As a novel material with efficient thermal conductivity, hBN made great contribution to the thermally induced shape memory and self-healing property. Systematic researches reveal that the composites are promising as long durable thermal interface materials, anti-scratch materials and so on.
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高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2020
·Vol. 26
·期 45
·10307-10313
·
IF 4.857
Chang-Qing Jing,Juan Wang,Hui-Fang Zhao,Wen-Xin Chu,Yun Yuan,Zhi Wang,Meng-Fei Han,Te Xu,Jian-Qiang Zhao,Xiao-Wu Lei
Graphical Shining white : With the aim of optimizing the broadband white-light emission performance of low-dimensional perovskites, isomorphic 2D perovskites [DMEDA]PbCl 4 and [DMPDA]PbCl 4 were structurally designed on the basis of homologous amine templates. The subtle regulation of organic cations leads to increased distortion of the 2D [PbCl 4 ] 2− layers and enhancement of the photoluminescence quantum efficiency from <1 to 4.9 %. DMEDA: dimethylethylenediamine, DMPDA: N , N -dimethyl-1,3-diaminopropane. Recently, 2D organic–inorganic hybrid lead halide perovskites have attracted intensive attention in solid-state luminescence fields such as single-component white-light emitters, and rational optimization of the photoluminescence (PL) performance through accurate structural-design strategies is still significant. Herein, by carefully choosing homologous aliphatic amines as templates, isotypical perovskites [DMEDA]PbCl 4 ( 1 , DMEDA= N , N -dimethylethylenediamine) and [DMPDA]PbCl 4 ( 2 , DMPDA= N , N -dimethyl-1,3-diaminopropane) having tunable and stable broadband bluish white emission properties were rationally designed. The subtle regulation of organic cations leads to a higher degree of distortion of the 2D [PbCl 4 ] 2− layers and enhanced photoluminescence quantum efficiencies (<1 % for 1 and 4.9 % for 2 ). The broadband light emissions could be ascribed to self-trapped excitons on the basis of structural characterization, time-resolved PL, temperature-dependent PL emission, and theoretical calculations. This work gives a new guidance to rationally optimize the PL properties of low-dimensional halide perovskites and affords a platform to probe the structure–property relationship.
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PubMed
高影响因子
Materials Today Communications
·
2020
·
IF 2.678
B. Wang,Z.Y. Li,J.N. Xu,F.Y. Liu,Y.D. Liu
Repetitive use and effective recycling of the materials are vital to overcome the current environmental challenges. In case of polymeric materials, the high curing temperatures significantly limit their application. In this study, a series of polymers with thermal reversibility at room temperature were synthesized. The main chain of the polymer systems was composed of polyethylene glycol diglycidyl ether (PEGDGE) and polypropylene glycol diglycidyl ether (PPGDGE). The polymers were obtained by initial chain-extension of furfurylamine (FA) and subsequent Diels-Alder (DA) reaction with bismaleimide (BMI). Fourier transform infrared spectroscopy analysis revealed that the material exhibited fast curing rate and high conversion rate, with the conversion rate reaching 98 %. DSC and DMA characterization demonstrated that the reverse reaction occurred at about 100℃. The tensile analysis confirmed that the mechanical properties of the developed materials remain largely unchanged after recycling, as compared with the existing materials.
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高影响因子
ACS Omega
·
2020
·
IF 2.87
Guangming Lu,Jinyue Dai,Jingkai Liu,Shu Tian,Yongjian Xu,Na Teng,Xiaoqing Liu
With the rapid development of bio-based polymers, polybenzoxazine derived from renewable resources has been widely investigated. However, there are few reports on the functional application of bio-based polybenzoxazine based on the special chemical structures of renewable compounds. In this work, an easy approach to prepare the polybenzoxazines with varied thermomechanical properties and excellent marine antifouling performance from renewable resources is presented. After a variety of main-chain-type benzoxazine polymers (MCBPs) were synthesized from the renewable daidzein, furfurylamine, polyetheramine, and paraformaldehyde, their chemical structures were identified by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (1H NMR). Then, their curing behaviors were monitored by differential scanning calorimetry and rheological tests. Results revealed that the cross-linked MCBPs with varied thermomechanical properties could be easily prepared by adjusting the molar ratio of polyetheramine and furfuramine. Notably, these cured MCBP films demonstrated excellent antibacterial and algaecidal properties due to the presence of daidzein and furan units. This work first presents the new application prospect of bio-based MCBPs, for example, in marine antifouling coatings.
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高影响因子
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