JOURNAL OF APPLIED POLYMER SCIENCE
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2022
·Vol. 140
·期 4
·e53372
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IF 3.057
Guohao Miao,Hai Zhang,Yu Yang,Jin Qu,Xinru Ma,Junping Zheng,Xiaofei Liu
Zirconium is one of the most commonly used crosslinkers for guar gum-based fracturing fluid. Nevertheless, it is difficult for zirconium crosslinkers applied in fracturing to possess both high temperature resistance and adjustable crosslinking time. Meanwhile, few people did systematical research on the crosslinking process of fracturing fluid. In this study, an organic zirconium crosslinker with high temperature resistance and controllable crosslinking time was synthesized. The seawater-based fracturing fluid gel prepared with the crosslinker could perform well under 170°C. Oscillatory shear experiments were conducted to analyze the rheology of the gelation process. Moreover, steady-state shear and micro-rheological tests were conducted to analyze the dynamic and static crosslinking process of the fracturing fluid, respectively. Meanwhile, rheo-kinetic equation was used to fit the data and the effects that various factors had on the gelation process were illustrated thoroughly. This study not only prepared an organic zirconium crosslinker with good performances, but also explored the crosslinking process of fracturing fluid gel, which could improve its further application in oilfields.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 4
·e53352
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IF 3.057
Heng Li,Yu Guo,Buyun Ma,Yunzhu Qian,Wentao Sun,Xuefeng Zhou
Surface heparinization is an effective solution to resolve low endothelialization, poor anticoagulation, and hemocompatibility of polyurethane (PU) used as materials of small-diameter vascular grafts. Here, the effects of polydopamine (PDA) and poly (acrylic acid) (PAA) as crosslinking agents on the surface heparinization were explored. The PU membranes grafted with heparin (Hep) via dopamine (PU/PDA-Hep) showed better hydrophilicity and stability, compared to heparinized PU membranes via acrylic acid (PU/PAA-Hep). The results of X-ray photoelectron spectroscopy demonstrated that heparin was successfully grafted onto the PU surface and the grafting efficiency was high when PDA as a cross-linking agent. The grafted heparin aggregated and formed nanoparticles, and increased the surface roughness of PU membranes. The heparinized membranes demonstrated good anti-adhesion of bovine serum albumin and fibrin protein. In addition, no activated platelets or educts on heparinized PU were found by platelet adhesion tests, implying that heparin-immobilized surfaces had good hemocompatibility. Moreover, the in vitro cytocompatibility assessment showed that the PU/PDA-Hep significantly improved the proliferation of L929 cells and was superior to PU/AA-Hep. These results demonstrated that PDA-assisted surface heparinization was an effective method to improve the anticoagulant and biocompatibility of PU small-diameter vascular materials and could be extended to other implantable materials.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 2
·e53301
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IF 3.057
Wenwen Wu,Qingquan Song,Junrong Yu,Na Li,Zuming Hu,Yan Wang,Jing Zhu
The high-performance polymer para-aramid (PPTA) is discovered to gel too soon during the polymerization process, resulting in poor processing performance. In this work, a homogeneous polymer solution containing heterocyclic para-aramid (HPPTA) was successfully synthesized by introducing 2,4-aminophenyl-5-aminobenzimidazole groups into the molecular chains of PPTA, and then HPPTA aerogel was prepared using a supercritical drying technique that took advantage of the HPPTA solution's excellent property of slow gelation. When the HPPTA polymer mass fraction was 1 wt%, the aerogel had the lowest density of 0.086 g cm −3 with a BET specific surface area of 376.59 m 2 g −1 . The HPPTA-2 aerogel had better adsorption performance for anionic dye methyl orange, with a maximum adsorption capacity of 319.47 mol g −1 ; however, its adsorption capacity for cationic dye methylene blue and neutral dye dimethyl yellow was very low, at only 19.68 and 0 mol g −1 , respectively. The selective adsorption ability of HPPTA aerogel made it a simple and scalable platform for removing anionic dyes from water solutions. Furthermore, the HPPTA aerogel has outstanding thermal properties for thermal insulation applications in severe environments due to the synergistic effect of the 3D porous structure inside the aerogel and the exceptional thermal stability of the HPPTA.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 5
·e53397
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IF 3.057
Chen Zhang,Ruiyun Cai,Chuanbang Xu,Hongwei Xia,Yun Zhu,Shengmiao Zhang
Effective flame retardant strategy for open-cell foam (e.g., polyHIPE) remains of a great challenge. Herein, a void surface flame retardant strategy for polyHIPE was presented. An open-cell polystyrene (PS) polyHIPE was fabricated through an emulsion-templating technique. Polyphosphazene (PSZ), a highly efficient flame retardant polymer, was then in situ fabricated and covalently attached to the void surface of the foam to be a uniform flame retardant protective layer, while the open-cell structure of the foam was perfectly preserved. Compared with the pristine PS polyHIPE, the PSZ modified one had significantly improved thermal stability (char residues yield at 800°C increased from 3.36 to 16.53 wt%) and mechanical properties (Young's modulus increased by 2.6 times); the values of average heat release rate and total heat release of combustion were reduced by 62.36% and 41.57%, respectively. While, the value of limiting oxygen index was increased from 17.39% to 19.75%, owing to the combined action of condensed phase flame retardant and gas phase flame retardant. These results indicate that the in situ surface modification strategy is effective for improving the flame retardancy of highly interconnected polymer foams.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 2
·e53285
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IF 3.057
Yifeng Gao,Linlin Wu,Jiacheng Zhou,Xiaofeng Ma,Ying Fang,Xianli Fang,Qiang Dou
Owing to the advantages of temperature resistance, low cost, and biocompatibility, deep eutectic solvent (DES)-based ionic conductive gels have attracted increasing research interest for flexible devices in recent years. However, current DES gels are all based on hydrophilic DES, which tend to absorb a large amount of environmental moisture, resulting in gel softening and adversely affecting the durability of the device. In this work, we highlight for the first time that N , N -dimethylacrylamide monomer, and the obtained polymer can form hydrogen-bonding networks with hydrophobic DES, methyl trioctyl ammonium chloride/ethyl 4-hydroxybenzoate (1:2), thereby obtaining a hydrophobic DES-based gel through photo-polymerization. The resultant DES gel displays high stretchability (~900%), toughness (341.14 kJ m −3 ), anti-fatigue property (recovery after 500 compression cycles), desirable conductivity (0.12 mS cm −1 ), adhesiveness and high transparency (>90% visible light transmittance). Notably, the hydrophobic DES-based gel absorbs only 2 wt% water but exhibits significant water-induced stiffening after exposing in ambient air for 1 week. These properties lead to the successful realization of the DES gels as wearable sensors to precisely monitor human motion. This work may open new avenues for the development of hydrophobic DES-based gel ionotronics with functional performance.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 3
·e53320
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IF 3.057
Lijun Guo,Yuxin Gao,Jin Huang,Jingqi Xue,Feng Li,Cuiqin Li
The functionalized covalent organic framework materials play an important role in catalytic application. A convenient tactic is developed to design and synthesize an imine-linked covalent organic frameworks (COFs) material (COF-PD) with abundant nitrogen atoms, which can provide coordination active site and facilitate the incorporation of COFs with nickel ions. Nickel-coordinated COF-PD complex (COF-PD-Ni) is prepared and used in ethylene oligomerization. COF-PD-Ni displays the highest catalytic activity of 1.98 × 10 5 g/(mol·Ni·h) in ethylene oligomerization with MAO as co-catalyst and cyclohexane as solvent. Various reaction parameters including reaction temperature, time, solvent, and the amount of cocatalyst are evaluated in detail, dramatically impacting the catalytic activities as well as the distribution of the products. What is more, the effect of COFs structure on the catalytic performance is also studied, suggesting more coordination sites were more important for high activity.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2022
·Vol. 140
·期 4
·e53364
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IF 3.057
Yannan He,Dacheng Qiu,Zhiqiang Yu
Failure mechanism of rigid polyurethane foam (RPUF) treated under different conditions was studied by means of experiments and numerical simulation. Thermal degradation mechanism of RPUF under different temperatures was characterized by thermogravimetric analysis-Fourier transform infrared spectrometry coupled with gas chromatography–mass spectrometry (TG-FTIR-GC–MS) in air and nitrogen atmosphere, respectively. And the vibration failure mechanism of RPUF was analyzed by finite element analysis (FEA) and extended finite element method (XFEM). The experimental results indicated that the failure mode in nitrogen was the broken of carbamate groups, and in air was the broken of carbamate groups and the radical decomposition of ether groups. Numerical simulation suggested that there was vibration stress concentration in the center of foam prism, which was easy to produce sliding and opening fatigue cracks during random vibration.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 2
·e53287
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IF 3.057
Min Pan,Pengtao Wang,Zhe Xu,Yu Kuai
A new pathway to construct high-strength, ultrastretchable hydrogels based on tailored modified carboxymethyl cellulose (TMCMC)and hydrophobic association(HPA) system was investigated. TMCMC was prepared from degradation of carboxymethyl cellulose (CMC)/N,N′-methylene bisacrylamide (MBA) chemical cross-linked hydrogels. The residual double bonds of TMCMC, confirmed by 1 H-NMR and FTIR analysis, reacted with acrylamide in HPA to form TMCMC/HPA hydrogels, and the homogeneous and fine spatial network structure of TMCMC/HPA hydrogel could be observed by scanning electron microscopy. Rheological analysis revealed that the coexistence of physical and chemical crosslinking in TMCMC/HPA hydrogels. Further studies showed that TMCMC/HPA hydrogel with MBA content of 0.5 wt% has outstanding mechanical properties, and its fracture stress, elongation and tensile strength reach 1.17 MPa, 3717.05% and 15.68 MJ·m −3 , respectively. Moreover, the hydrogel displayed good swelling resistance and stable strain electrical signal response.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 48
·e53209
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IF 3.057
Muchao Qu,Jiaqiang Fang,Chenzhong Mu,Yanfeng Li,Shaojuan Huang,Lei Han,Stefan Hiemer,Wei Xu,Yijing Qin
In this study, a flexible strain sensor consisting of carbon nanotubes (CNTs) and ethylene-vinyl acetate (EVA)-based hot-melt adhesive web (HAW) is proposed with the advantages of low cost and easy fabrication. Six different weight fractions of the CNTs were employed in producing the three-layer sandwich-structure composite membrane. The morphology and internal particle structure of the cross section of the EVA/CNTs composite membranes was studied using scanning electron microscopy. The mechanical properties as well as the mechanical–electrical behavior of the EVA/CNTs sensors were investigated, showing a gauge factor up to 477. In addition, two mathematical equations to establish the relationship between the output electrical signal and the input strain signal during the monotonic and cyclic measurements were proposed, respectively. Overall, this study provides a solvent-free one-step approach for the preparation of flexible strain sensors with innovative and broad application prospects, and offers some insight into the mathematical prediction of the strain sensing behavior.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 4
·e53211
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IF 3.057
Wei Wu,Hailan Zeng,Weiran Zhang,Weili Zhang,Haiyun Jiang,Guohua Wu,Ziyu Li,Xiang Wang,Yiyang Huang,Zhiyong Lei
Poly(3,4-ethylene dioxythiophene) (PEDOT) is a promising electrochromic material in many practical application, such as smart windows and displays. However, there are still difficulties in currently realizing green manufacturing, high coloration efficiency, and rapid response. Herein, in-situ electrochemical polymerization of PEDOT:PSS/Reline films was suggested in aqueous solution. Deep eutectic solvents (DES) composed of choline chloride and urea (Reline) were employed as green solvents in reaction system and used as dopants for the PEDOT:PSS. The as-prepared PEDOT:PSS/Reline films exhibited remarkable electrochromic properties, including great ion diffusion coefficient, fast reaction time (coloration response time was 1.4 s), prominent transmittance modulation (38%), high coloration efficiency (223 cm 2 /C) and excellent cyclic stability. Impressively, doping of Reline cannot only provide a green polymerization environment, but also significantly boost the electrochromic properties.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 46
·e53247
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IF 3.057
Weikun Jia,Lan Wang,Yan Xu,Xiaotao Wen,Xueyan Ma,Zhaoyang Cui
To overcome the poor conductivity of electrode film in bio-gel electroactive actuator, graphene was introduced into its structure to prepare a kind of bio-gel electroactive actuator based on chitosan, and its actuation characteristics were analyzed. First of all, the output characteristics of the electroactive actuator prepared with the addition of graphene oxide （GO）were tested to obtain the variation patterns of bending force and displacement. Second, electrochemical and microscopic tests were carried out and the water retention rate was analyzed to explore the internal reasons for the improvement of output characteristics. Third, how the mass fraction of GO influences the polymer electroactive actuator's bending force performance was comprehensively analyzed. The results show that adding GO significantly improved the electroactive actuator's performance. Adding graphene oxide into the polymer actuator was proved to be an effective strategy to improve the actuator's actuation properties.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 48
·e53231
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IF 3.057
Shang Ke Yang,Zhao Xin Zhang,Ai Ping Zhang,Hai Lan Lin,Xun Tao Zhang,Liu Xin Xiao,Jun Bian,Dai Qiang Chen
This work employed polymer active agent polyvinylpyrrolidone (PVP) treated barium titanate (BT) nanoparticles (PVP@BT) as functional nanofillers to fill polyimide (PI) matrix to fabricate PI nanocomposite films. The microstructure, dielectric properties, and heat resistance of PI, PI/BT, and PI/PVP@BT dielectric nanocomposite films were investigated. Fourier transform infrared spectrometer (FTIR) indicated that PVP has been successfully coated on the surface of BT nanoparticles. Due to the enhanced aggregation of monomers on the PVP@BT nanoparticles, higher molecular weight and viscosity of PI/PVP@BT nanocomposite films were achieved. Compared with PI/BT nanocomposite films, the dispersion of PVP@BT nanoparticles in PI/PVP@BT nanocomposite films was better, as verified by field emission scanning electron microscope and high-resolution transmission electron microscopy. Filling a small amount of PVP@BT nanoparticles into the PI matrix improved the dielectric properties of the resultant nanocomposite films. The dielectric constant of the nanocomposite films with 10 wt% filler loading was up to 7.1 at 1000 Hz, which was 2.5 times higher than that of pure PI (2.9). PI nanocomposite film dielectric loss was generally lower than 0.015. Thermogravimetric analysis (TGA) tests verified that both pure PI and PI nanocomposite films showed excellent thermal stability. This work can be expected to provide a new strategy for designing and manufacturing PI dielectric nanocomposite films for energy storage applications.
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高影响因子
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