JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 16
·48595
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IF 2.188
Mengfan Liang,Yu Wang,Shuhong Sun,Wenlong Yang
In this article, the effects of coupling agent, silica particle size, and particle shape on the mechanical properties of polyimide (PI) were studied by molecular dynamics (MD) simulations, and the effect of SiO 2 surface treated with coupling agent on the mechanical properties of PI was investigated by experiment. At the same doping volume fraction (5%), the simulation results show that the surface interaction energy between the matrix and particle gradually increases with the radius of the embedded nanoparticles. Meanwhile, the interface interaction energy and mechanical properties of the sphere-type were significantly higher than the ones of other shaped nanoparticles. Moreover, the simulations were compared with the experimental results; atomic force microscopy and scanning electron microscopy images can verify that after being treated with coupling agent, interface interaction between nanosilica and PI enhances quite a little. The mechanical experimental results show that the tensile strength and elasticity modulus of pure PI, unbonded (UB) PI/SiO 2 , and bonded PI/SiO 2 films are 34.47 and 1.13, 36.46 and 1.32, and 66.20 MPa and 1.72 GPa, respectively. It is indicated that the coupling agent plays a crucial role in nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48595.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 15
·48564
·
IF 2.188
Yunyun Yu,Yanlai Wang,Penghu Deng,Tonghua Zhang
This work presented a new method for preparing cellulose nanofibril (CNF)/Fe 3 O 4 @rGO composite aerogels with enhanced magnetic and mechanical properties. The composite aerogels were obtained through compounding, gelling, washing, tert -butanol replacing, and freeze-drying. The structural characteristics of composite aerogels were investigated via scanning electron microscopy, Fourier transform infrared, and X-ray diffraction. Results showed that the composite aerogels had interconnected three-dimensional porous network microstructures, and the Fe 3 O 4 @rGO hybrids were uniformly dispersed in the aerogels. Moreover, the aerogels' magnetization and compression characteristics were also studied. Magnetic measurements indicated that composite aerogels had good magnetization characteristics with the saturation magnetization value of 6.75 emu/g. The uniaxial compression tests showed that the compression strength and Young's modulus of the composite aerogels were significantly improved by 32.33 and 118.56%, respectively, relative to those of CNF aerogels. The perfect combination of structure and performance may render the composite aerogels useful for commercial applications in the fields of environmental engineering, biomedical engineering, electronics, and energy. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48564.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 24
·48808
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IF 2.188
Shuwei Cai,Haijun Niu
In this study, four novel triarylamine-based polyimides with different substituted groups (tert-butyl and -H) containing pyrrole moieties were successfully prepared by polycondensation reaction. The electrochemical and electrochromic properties of the polyimides were measured by cyclic voltammetry and spectro-electrochemistry. The polyimides exhibited obvious electrochromic behavior with good thermal stability (the 10% weight-loss temperatures were recorded in the range of 345-386°C), film-forming ability and reversible stability after 1000 s. The color of the polyimide films changed from colorless to light blue or yellow to blue on increasing the applied potential. The highest coloration efficiency reached up to 190 cm 2 C −1 . The polyimide films exhibited a stable response to the light (on or off) after 200 s. Especially, PyHBTPI displayed effective solubility, superior optical contrast (~30%) in the visible region, faster response time (1.19 s for coloring process), and obvious color change from yellow to blue with good stability, thus, confirming the potential use for high contrast displays. Overall, the study demonstrates the successful development of high-performance polyimides for electrochromic and optoelectronic behaviors. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48808.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 26
·48849
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IF 2.188
Xin Li,Jin Wang,Yibo Zhao,Xuetong Zhang
The hydrophobilization of aerogels is critical for their long-term application due to their highly open-porous structures, while the hydrophobilization strategies for polyimide (PI) aerogels are limited. In the present work, a feasible strategy to synthesize superhydrophobic PI aerogels is proposed via a conformal-coating process. The resulting PI aerogels (F-PI) exhibit high contact angles up to 156°. Impressively, the F-PI aerogels show excellent water-resistant capacity not only in the ambient condition but also in the high-pressure water up to 0.5 MPa, where the liquid cannot or only partially permeate into the aerogel's open pores. Besides, the F-PI aerogels possess high Brunauer–Emmett–Teller surfaces areas (185 m 2 g −1 ), high Young's modulus (3 MPa), low thermal conductivity (0.056 W m −1 ·k −1 ), and variable densities. All these parameters are found to be well preserved after high pressure (0.1–0.2 MPa) water treatment, further indicating the excellent water-resistant performance of the F-PI aerogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48849.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 18
·48634
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IF 2.188
Guoqiang Wang,Yin Liang,Min Jiang,Qiang Zhang,Rui Wang,Honghua Wang,Guangyuan Zhou
The purpose of this study was to enhance the glass-transition temperature of poly(butylene 2,5-thiophenedicarboxylate) (PBTF). A series of poly(butylene- co -1,4-cyclohexanedimethylene 2,5-thiophenedicarboxylate)s (PBCTFs) were synthesized from 2,5-thiophenedicarboxylic acid, 1,4-cyclohexanedimethanol (CHDM), and 1,4-butanediol. CHDM can increase the chain rigidity and lead the β relaxation temperature shift to lower temperature. Consequently, PBCTFs showed not only the high glass-transition temperature, but also high elongations at break. PBTF was a crystalline polyester. However, differential scanning calorimetry and wide-angle X-ray diffraction results suggested PBCTFs were amorphous polyesters. Thermogravimetric analysis results indicated the thermal stability of copolyesters was gradually enhanced with increasing the CHDM content. When the CHDM content was 95 mol %, PBCTF95 exhibited high glass-transition temperature (69.2 °C), tensile strength (44.4 MPa), and elongation at break (205%). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48634.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 19
·48671
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IF 2.188
Huiqing Wei,Xidong Suo,Chunxiang Lu,Yaodong Liu
The fiber spinning methods determine the formation of the physical structures of polyacrylonitrile (PAN) fibers which further affect stabilization reactions and the mechanical performances of the resultant carbon fibers. In this study, PAN fibers were prepared by both dry-jet gel spinning (g-PAN) and dry-jet wet spinning (w-PAN), and their stabilization behaviors were compared. While the stabilized w-PAN fibers show sheath-core structures, the stabilized g-PAN fibers exhibit relatively uniform stabilized structures along the radial direction. Additionally, the stabilization reactions of g-PAN fibers occur faster than that of w-PAN fibers, and the cyclization, oxidation, and crosslinking reaction activation energies of g-PAN fibers are lower than that of w-PAN fibers, respectively. Moreover, the carbon yield of g-PAN is higher than that of w-PAN fibers. We believe that above changes are possibly ascribed to the formation of different PAN sheath structures and oriented chain structures during dry-jet wet spinning and dry-jet gel spinning. It is concluded that gel spinning could significantly reduce the sheath-core difference of PAN fibers and the stabilized fibers as compared with wet spinning, which leads to a faster stabilization and more uniform stabilized structures. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137 , 48671.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 16
·48594
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IF 2.188
Rui Wang,Yao Xiao
In this study, we prepared monosultap microcapsules in an inverse emulsion through interfacial polymerization for the first time. The microcapsules are spherical pellets with intact and smooth shell and have a narrow particle size distribution with an average size of about 2.35 μm. More importantly, our microcapsules have excellent thermal stability with a starting decomposition temperature of 233.1 °C, high encapsulation efficiency of 81.9% as well as long-term slow release of monosultap under different conditions. In addition, the shell of the microcapsules can degrade completely in the natural condition, avoiding the pollution to the environment. It can be believed that our microcapsules will show good service performance if employed in agricultural industry. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48594.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 16
·48588
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IF 2.188
Xianyou Wu,Jing Qian,Chao fu,Zhongyang Tan,Yixing Gao,Antong Ma,Wei Nie,Xianghai Ran
In this work, we fabricated a triple-shape memory polymeric material though in situ crosslinking of poly(butylene adipate- co -terephthalate)/ε-polycaprolactone blends induced by electron beam irradiation. The intrinsic property of irradiation crosslinking, crosslinking rule in this heterogeneous system, formation of interfacial bridge molecular, and the resulted interfacial strength were investigated. No obvious interfacial slips were observed in tensile test, and the elongation at break was above 900%. The high-temperature relaxation and recovery experiments at nonlinear region confirmed the excellent hyperelasticity and recovery ratios ( R r ) can be as high as 95% for samples irradiated above 96 kGy. The mismatch between heating rate and relaxation kinetics resulted in both instable temporary shapes and heating-mode dependent recovery behavior during the recovery process. Self-stability of the temporary shape at middle temperature was also emphasized in view of the phenomenon that the second R r was above 100% in our experiments. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48588.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 17
·48609
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IF 2.188
Qiaoran Zhang,Mengmeng Zhang,Huili Shi,Zhiwei Li,Laigui Yu,Xiaohong Li,Zhijun Zhang,Zhishen Wu
Boron nitride nanosheets (BNNSs) were combined with ammonium polyphosphate (APP) and zinc ferrite (ZF) nanoparticle to prepare APP/BNNS/ZF composite aerogels via a freeze-drying method. Then, epoxy resin (EP) was incorporated into the pores of the as-obtained aerogels via a vacuum-assisted infiltration method to afford APP/BNNS/ZF-EP composites with greatly improved fire resistance. The flame-retardant performance of the as-prepared composites was evaluated by cone calorimetry test; and the flame-retardant mechanism of the aerogels was discussed in relation to thermogravimetric-infrared analysis of the pyrolysis products. Findings demonstrate that the APP/BNNS/ZF-EP composite containing 24.0 wt % of the APP/BNNS/ZF aerogel exhibits superior flame-retardant performance; and its peak heat release rate and total heat release are reduced by 86.2 and 86.5% as compared with those of pristine EP. The reason lies in that APP can be decomposed in the early stage of burning to generate phosphoric acid, thereby promoting the formation of char layer; ZF can catalyze the charring process; and BNNS can act as the physical barrier to retard the burning of EP. In addition, the APP10/BNNS1/ZF0.1-EP composite can be endowed with superhydrophobicity via the modification of polydimethylsiloxane and hydrophobic nanosilica, which could contribute to broadening its scope of application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48609. Highlights 1 Flame-retardant APP/BNNS/ZF aerogels were prepared by a freeze-drying method. 2 APP/BNNS/ZF-EP composites were obtained via a vacuum-assisted infiltration method. 3 The pHRR of composites are reduced by 86.2% as compared with that of pristine EP. 4 The EP composites exhibit excellent flame retardancy and superhydrophobicity.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2019
·Vol. 137
·期 24
·48809
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IF 2.188
Rubin Wei,Bin Dong,Fenglong Wang,Jingjing Yang,Yanyan Jiang,Wen Zhai,Hui Li
Shear-thickening fluid (STF) refers to a system where nonaggregating solid particles are suspended in a specific fluid. Due to its unique viscosity variation, STFs have attracted a lot of attention as soft body armor materials for impact protection. In this work, two kinds of STFs were designed using polyethylene glycol (PEG) and spherical or irregularly shaped silica particles. Rheological results showed that shear thickening can even occur at lower shear rates in the irregularly shaped silica-based STF; however, the thickening range of the spherical silica-based STF was broader. Meanwhile, the composites prepared with STFs and aramid fabrics exhibited better antistab properties than neat fabrics. Compared to composite prepared with irregularly shaped silica-based STF, spherical silica-based STF/aramid composite had better stabbing resistance. In addition to the binding effect of silica particles to the fiber bundle, it was considered that when the fabric composite was subjected to impact, spherical particles were easier to slide so that the STF was more likely to be thickened to achieve a greater viscosity, resulting in the better stabbing resistance performance. Our studies will provide guidance for the design of the high-performance soft body armor equipment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48809.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 14
·48541
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IF 2.188
Yinyan Guan,Li Wang,Li Cui,Xinjun Shen,Weichun Gao,Jing Meng,Dan Li,Chenguang Shen,Yichen Zhang,Guodong Hu,Jiyan Liang
In this article, tough hydrogels are prepared by introducing the polyethyleneimine (PEI) with branched structure and a large number of NH 2 and NH groups into permanently crosslinked polyacrylamide (PAAm) hydrogels matrix. To investigate the effects of B-PEI and chemical crosslinking agent (Bis) on the strength and toughness of hydrogels, a series of B-PEI/PAAm hydrogels with different mass percentage of Bis and B-PEI were manufactured and the rheological and swelling properties were compared. For all hydrogels, the storage modulus ( G ′) was much higher than the loss modulus ( G ″) in the linear viscoelastic region through the whole frequency range. The solid-like behavior and elastic nature ( G ′ > G ″) are attributed to the permanent covalence crosslinking. Therefore, G ′ increased when more Bis was added. For the nonlinear oscillatory shear measurement, hydrogels with B-PEI broke at larger γ than the pure PAAm hydrogels, indicating that the toughness of B-PEI/PAAm hydrogels has been improved by introducing B-PEI. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48541.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 24
·48804
·
IF 2.188
Yan Feng,Runjun Sun,Chengkun Liu,Meiyu Chen,Qiushi Wang
The electrospun polyamide 6 (PA6) membranes are treated with different methods. The rough surfaces with different protuberances size and the fiber diameter are prepared by wet, dry heat, wet heat, and ethanol treatments under relaxation, and the formation mechanisms are analyzed. A relative stable structure of PA6 membrane is also prepared by ethanol treatment under tension, and its structure is as same as the untreated membrane. The dynamic water contact angles (WCAs) of the treated membranes are measured. The starting WCA of the membrane with wet heat treatment under relaxation is 90.95°, which is larger than those of wet, dry heat, and ethanol treatments under relaxation. The effects of surface morphologies with different treatments on wettability are analyzed. For obtaining hydrophobicity, the membrane with wet heat treatment under relaxation was coated by polyvinylidene fluoride (PVDF). The WCA of the membrane increases to 127.1° after coating. From another point of view, the WCA of the PVDF/treated PA6 membrane is much larger than that of the pure casting PVDF membrane, which means the rough surface of the treated PA6 membrane can improve the hydrophobicity of the PVDF membrane. Furthermore, the membrane is endowed with superhydrophobicity (WCA of 153.5°) after being coated by SiO 2 /PVDF due to the multilevel structured surface roughness. It is a relative low cost and convenient operation method to prepare the superhydrophobic material. The results provide a novel preparation method of the superhydrophobic material and a treatment method of the electrospun PA6 membrane to obtain a stable structure. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48804.
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高影响因子
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