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Chinese Journal of Chemical Engineering 2022年第6期35卷 231-242页

作者： Tong Qin zhenhao xi Ling Zhao Weikang Yuan State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China College of Chemistry and Chemical Engineering Xinjiang UniversityUrumqi 830046China

The regulation of polyacrylonitrile(PAN)copolymer composition and sequence structure is the precondition for producing high-quality carbon fiber high *** this work,the sequential structure control of acrylonitrile(AN),methyl acrylate(MA)and itaconic acid(IA)aqueous copolymerization was investigated by Monte Carlo(MC)*** parameters used in Monte Carlo were optimized via machine learning(ML)and genetic algorithms(GA)using the experimental data from batch *** results reveal that it is difficult to control the aqueous copolymerization to obtain PAN copolymer with uniform sequence structure by batch polymerization with one-time *** contrary,it is found that the PAN copolymer with uniform composition and sequence structure can be obtained by adjusting IA feeding quantity in each reactor of a train of five ***,the results obtained in this work can provide valuable information for the understanding and optimization of AN copolymerization process to obtain high-quality PAN copolymer precursor.

关键词： Polyacrylonitrile Monte Carlo simulation Machine learning Genetic algorithms Sequence structure Operation method

Experimental and simulation study of nylon 6 solid–liquid extraction process

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Chinese Journal of Chemical Engineering 2018年第5期26卷 1022-1030页

作者： Chunxi Qin Jie Tang Fenglei Bi zhenhao xi Ling Zhao Shanghai Key Laboratory of Multiphase Materials Chemical Engineering East China University of Science and Technology State Key Laboratory of Chemical Engineering East China University of Science and Technology

The solid–liquid extraction process of nylon 6 to eliminate small molecules, i.e., caprolactam(CL), cyclic dimers(CD) and cyclic trimers(CT), is investigated in detail by both batch extraction experiments and numerical simulations. In the batch extraction experiments, due to the small molecules attaching to the polymeric surface, the basic physical mechanism shifts from surface diffusion to internal diffusion as the extraction proceeded. The experimental data are well reproduced by a diffusion model consisting of two distinct steps, characterized as surface diffusion and internal diffusion. Furthermore, based on the established mass transfer mechanism and diffusion model of the two distinct steps, the equilibrium constants and internal diffusion coefficients of CL, CD and CT are acquired. An industrial countercurrent extraction tower is further simulated. It is found that the extraction efficiency of CL can be significantly improved by increasing the temperature at the bottom portion of the tower. The elimination of CD, which can be greatly promoted by a high-concentration CL-water solution, is controlled by mass transfer resistance, whereas the removal of CL is mainly affected by the equilibrium.

关键词： Solid-liquid extraction Equilibrium Diffusion Numerical simulation

Synthesis and characterization of copolymers of poly(m-xylylene adipamide) and poly(ethylene terephthalate) oligomers by melt copolycondensation

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Chinese Journal of Chemical Engineering 2016年第9期24卷 1290-1297页

作者： Fenglei Bi Jianqiang Shao zhenhao xi Ling Zhao Di Liu Shanghai Key Laboratory of Multiphase Materials Chemical Engineering East China University of Science and Technology Beijing Sanlian Hope Shin-Gosen Technical Service Co. Ltd.

Poly（m-xylylene adipamide）/poly（ethylene terephthalate）（MXD6/PET） copolymers are synthesized by melt copolycondensation with 1–5 wt% low molecular weight PET oligomers into the MXD6 oligomers at 260 ℃.FR-IR and1 H NMR analysis results indicate that the interchange reaction has occurred between MXD6 oligomers and PET oligomers. The thermal behavior of copolymers shows that the melting temperature of MXD6/PET copolymers decreases with the increasing of amount of PET oligomers, while the crystallization temperature accordingly increases. And the equilibrium temperature Tm0 is evaluated to be 251.8 ℃ for the copolymers with5 wt% PET oligomer adding, which is very close to that of neat MXD6. The tensile and impact strength of MXD6/PET copolymers are significantly improved than that of pure MXD6 by mechanical properties test, and the microfibril structure in the impact fracture sample＇s surface reveals the feature of ductile fracture.

关键词： Polymerization Poly(m-xylylene adipamide) Poly(ethylene terephthalate) Crystallization Mechanical properties

High-efficiency acetaldehyde removal during solid-state polycondensation of poly(ethylene terephthalate) assisted by supercritical carbon dioxide

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Chinese Journal of Chemical Engineering 2018年第6期26卷 1285-1291页

作者： zhenhao xi Tian Liu Wei Si Fenglei Bi Zhimei Xu Ling Zhao State Key Laboratory of Chemical Engineering East China University of Science and Technology

The concentration of acetaldehyde(AA) is the main quality index of poly(ethylene terephthalate)(PET) used in food and drink packaging.A new method for AA removal has been developed by using supercritical carbon dioxide(sc CO2) during the solid-state polycondensation of *** influence factors of AA removal including the temperature,pressure,reaction time and the size of pre-polymer particles are systematically studied in this *** results indicate that it is a highly efficient way to obtain high molecular weight PET with relative low concentration of ***,the polymerization degree of PET could increase from 27.9 to 85.6 while the concentration of AA reduces from 0.229 × 10^(-6) to 0.055 × 10^(-6) under the optimal operation conditions of 230 °C,8 MPa and size of 0.30–0.45 *** performance tests show the increasing extent of PET crystallinity due to the fact that the plasticization of sc CO_2 is not obvious with extended reaction time,therefore the increasing crystallinity has no significant influence on AA *** observations reveal that the effects of sc CO_(2-) induced plasticization and swelling on PET increase significantly with the decrease of prepolymer size,and the surface of PET becomes more loose and porous in favor of the AA removal.

关键词： Supercritical CO2 Solid-state polycondensation Poly(ethylene terephthalate) Removal of acetaldehyde

Porous Metal-Organic Framework-Polymer Composites Using High Internal Phase Emulsion Templates: A Review

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Chinese Journal of Structural Chemistry 2022年第12期41卷 60-69页

作者： Yue Qiu Jin-Jin Li Ling Zhao zhenhao xi Weikang Yuan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China Shanghai Key Laboratory of Multiphase Materials Chemical Engineering East China University of Science and TechnologyShanghai 200237China

As promising engineering materials for green and sustainable processes, porous metalorganic framework(MOF)-polymer composites show great potential in applications, including adsorption, separation, catalysis, and bioengineering. Owing to the mild and scalable operation, porous polymeric materials derived from high internal phase emulsion templates(polyHIPE) have received great interests in recent decades. In this contribution, research progress of the preparation of porous MOF@polyHIPE composites and their applications are reviewed, highlighting how can MOF particles be shaped by HIPE templates, in particular the polymerizable ones. Four different emulsion templates stabilized by MOFs and the applications of corresponding MOF@polyHIPE are included. Hopefully,both the state-of-art and future directions present herein can give rise to the development of highperformance porous MOF@polyHIPEs.

关键词： high internal phase emulsion(HIPE) metal-organic frameworks(MOFs) adsorption and separation heterogeneous catalysis bioengineering

Phosphotungstic acid immobilized on amino-functionalized TS-1 zeolite as a solid acid catalyst for the synthesis of tributyl citrate

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Chinese Journal of Chemical Engineering 2024年第6期70卷 199-210页

作者： Pei Li Bianfang Shi Junyao Shen Ran Cui Wenze Guo Ling Zhao zhenhao xi State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

The amino-functionalization of TS-1 zeolite followed by immobilization of phosphotungstic acid(HPW)was presented to prepare a strong solid acid catalyst for the synthesis of bio-based tributyl citrate from the esterification of citric acid and n-butanol.γ-Aminopropyltriethoxysilane(APTES)was first grafted on the TS-1 zeolite via the condensation reactions with surface hydroxyl groups,and subsequently the HPW was immobilized via the reaction between the amino groups and the protons from HPW-forming strong ionic *** Keggin structure of HPW and MFI topology of TS-1 zeolite were well maintained after the *** amino-functionalization generated abundant uniformly distributed active sites on TS-1 for HPW immobilization,which promoted the dispersity,abundance,as well as the stability of the acid *** tetrahedrally coordinated framework titanium and non-framework titania behaved as weak Lewis acid sites,and the protons from the immobilized HPW acted as the moderate or strong Brønsted acid *** optimized TBC yield of 96.2%(mol)with a conversion of-COOH of 98.1%(mol)was achieved at 150℃for 6 h over the HPW immobilized on amino-functionalized *** catalyst exhibited good stability after four consecutive reaction runs,where the activity leveled off at still a relatively high level after somewhat deactivation possibly caused by the leaching of a small portion of weakly anchored APTES or HPW.

关键词： Amino-functionalization Phosphotungstic acid TS-1 zeolite Esterification Tributyl citrate

Multiblock poly(ether-b-amide)copolymers comprised of PA1212 and PPO-PEO-PPO with specific moisture-responsive and antistatic properties

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Chinese Journal of Chemical Engineering 2023年第1期53卷 421-430页

作者： Jie Jiang Wei Cheng Qiuyu Tang Xun Pan Jinjin Li Ling Zhao zhenhao xi Weikang Yuan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast ChinaUniversity of Science and TechnologyShanghai 200237China Shanghai Key Laboratory of Multiphase Materials Chemical Engineering East China University of Science and TechnologyShanghai 200237China Flinders Institute for Nanoscale Science and Technology Flinders UniversitySA 5042Australia College of Chemistry and Chemical Engineering Xinjiang UniversityUrumqi 830046China

Functional multiblock poly(ether-b-amide)(PEBA)copolymers,comprised of PA1212(polyamide 1212)as hard segments and Jeffamine ED-2003 as soft segments,were successfully prepared via two-step melt polycondensation without any amidation ***,using diamino-terminated poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide)(PPO-PEO-PPO),Jeffamine ED-2003,enhances the compatibility between polyamide oligomer and polyether,which is better than the traditional route using hydroxyl-terminated *** chemical structure of multiblock PEBAs,as well as the microphase separated structure with crystalline phase of polyamide and polyether,were confirmed by heteronuclear multiple-bond correlation spectrum,heteronuclear multiple quantum correlation spectrum,Fourier transform infrared spectroscopy(FT-IR),differential scanning calorimetry and dynamic mechanical *** hydrophilic PEBA copolymers showed water adsorption ranging from 87.3%to 17.1%depending on the polyether content,and specially showed moisture responsive behavior within seconds when exposed to *** corresponding mechanism was studied using time-resolved attenuated total reflectance FT-IR spectroscopy in the molecular level and the water diffusion coefficient was estimated to be 1.07×10^(–8)cm^(2)∙s^(-1).Two-dimensional correlation FT-IR spectra analysis was performed to confirm that the interaction between water and polyether phase was in preference to that between water and polyamide matrix,and water molecule only forms hydrogen bond with the polyether *** to the incorporation of PEO segments,the PEBAs have the surface resistivity varying from 5.6×10^(9)to 6.5×10^(10)Ω,which makes PEBA potential candidate as permanent antistatic agent.

关键词： Poly(ether-b-amide)s Moisture-responsive Antistatic In situ FT-IR 2D FT-IR analysis

Experiment and simulation of foaming injection molding of polypropylene/nano-calcium carbonate composites by supercritical carbon dioxide

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Chinese Journal of Chemical Engineering 2016年第1期24卷 180-189页

作者： zhenhao xi Jie Chen Tao Liu Ling Zhao Lih-Sheng Turng State Key Laboratory of Chemical Engineering East China University of Science and Technology Department of Mechanical Engineering University of Wisconsin–Madison

Microcellular injection molding of neat isotactic polypropylene(iPP) and isotactic polypropylene/nano-calcium carbonate composites(i PP/nano-CaCO_3) was performed using supercritical carbon dioxide as the physical blowing agent. The influences of filler content and operating conditions on microstructure morphology of i PP and i PP/nano-CaCO_3 microcellular samples were studied systematically. The results showed the bubble size of the microcellular samples could be effectively decreased while the cell density increased for i PP/nano-CaCO_3 composites, especially at high CO_2 concentration and back pressure, low mold temperature and injection speed, and high filler content. Then Moldex 3D was applied to simulate the microcellular injection molding process, with the application of the measured ScCO_2 solubility and diffusion data for i PP and i PP/nano-Ca CO_3 composites respectively. For neat i PP, the simulated bubble size and density distribution in the center section of tensile bars showed a good agreement with the experimental values. However, for i PP/nano-CaCO_3 composites, the correction factor for nucleation activation energy F and the pre-exponential factor of nucleation rate f_0 were obtained by nonlinear regression on the experimental bubble size and density distribution. The parameters F and f_0 can be used to predict the microcellular injection molding process for i PP/nano-CaCO_3 composites by Moldex 3D.

关键词： Microcellular injection molding Isotactic polypropylene/nano-calcium carbonate Cell morphology Nucleation activation energy Numerical simulation

Highly interconnected macroporous MBG/PLGA scaffolds with enhanced mechanical and biological properties via green foaming strategy

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Chinese Journal of Chemical Engineering 2021年第1期34卷 426-436页

作者： Chaobo Song Jiapeng Zhang Shuang Li Shengbin Yang Eryi Lu zhenhao xi Lian Cen Ling Zhao Weikang Yuan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China Department of Stomatology of Renji Hospital School of MedicineShanghai Jiao Tong UniversityShanghai 200127China Shanghai Key Laboratory of Orthopaedic Implant Department of Orthopaedics SurgeryShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineNo.639Zhizaoju RoadShanghai 200011China

In this study,mesoporous bioactive glass particles(MBGs) are incorporated into poly(lactic-co-glycolic acid)(PLGA) to fabricate highly interconnected macroporous composite scaffolds with enhanced mechanical and biological properties via a developed supercritical carbon dioxide(scCO_(2)) foaming method Scaffolds show favorable highly interconnected and macroporous structure through a high foaming pressure and long venting time foaming ***,scaffolds with porosity from 73% to 85%,pore size from 120 μm to 320 μm and interconnectivity of over 95% are controllably fabricated at MBG content from 0 wt% to 20 wt%.In comparison with neat PLGA scaffolds,composite scaffolds perform improved strength(up to 1.5 folds) and Young's modulus(up to 3 folds).The interconnected macroporous structure is beneficial to the ingrowth of *** importantly,composite scaffolds also provide a more promising microenvironment for cellular proliferation and adhesion with the release of bioactive ***,MBG/PLGA scaffolds developed by the green foaming strategy in this work show promising morphological,mechanical and biological features for tissue regeneration.

关键词： Scaffold Mesoporous bioactive glass Supercritical carbon dioxide Foaming Poly(lactic-co-glycolic acid)

Combined static mixers for high viscous fluids mixing

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Frontiers of Chemical Science and Engineering 2009年第1期3卷 93-96页

作者： zhenhao xi Weizhen SUN Ling ZHAO Zhaoyan LIU State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Beijing Innovation Polymerization Technology Company Beijing 100050China

A new static mixer Cross-over-Disc has been invented to strip off the boundary layer and to make strong radial *** pressure drop of Cross-over-Disc is 12–26 times as large as that of empty pipe with equivalent diameter and *** mixing performance of Cross-over-Disc with 14 elements has been investigated in the viscosity range of 190–250 Pa·s by decoloration method,and the gray analysis of images shows that mixing inhomogeneity is about 7.5%and 9.4%for the mixing ratio of 5∶1 and 10∶1,***,mixing inhomogeneity for a combination of static mixing elements(four from Cross-over-Disc and three pairs from Sulzer-type)can be decreased to 2.1%–3.1%within a reasonable range of pressure drop.

关键词： static mixer Cross-over-Disc pressure drop mixing performance high viscousﬂuid