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Design and Properties of Fluoroelastomer Composites via Incorporation of MWCNTs with Varied Modification

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Chinese Journal of Polymer Science 2020年第9期38卷 983-992,I0007页

作者： Guang-Yao Yang Li-Fen Tong xiao-bo liu Research Branch of Advanced Functional Materials School of Materials and EnergyUniversity of Electronic Science and Technology of ChinaChengdu 610054China

Multi-walled carbon nanotubes(MWCNTs)modified with silane coupling agent A-1120(MWCNTs-A1120)were *** with the raw MWCNTs,acidified MWCNTs(MWCNTs-COOH),and MWCNTs grafted with EDA(MWCNTs-NH2),MWCNTs-A1120 have the best dispersion in fluoroelastomer at the same doping ***,fluoroelastomer/MWCNTs-A1120 composite has the best mechanical properties with tensile strength of 13.92 MPa and elongation at break of 111.78%.Then,the effects of doping amount of MWCNTs-A1120 on the electrical properties of the composites were *** dielectric constant of the composite increases with the increase of MWCNTs-A1120,and the dielectric loss does not change much at the low doping amount such as 0.5 wt%.When the doping amount of MWCNTs-A1120 is 5 wt%,the dielectric constant and the dielectric loss value are greatly increased,and the volume resistivity is greatly decreased,which proves that the conductive network is formed in the composite,so the filling amount of 5 wt%is the percolation *** tensile deformation of the sample also affects the electrical properties of the *** the tensile deformation increases,the dielectric constant and dielectric loss of the composite *** the composite with 5 wt%MWCNTs-A1120,excessive tensile deformation will destroy the conductive network structure of the composite,so the composite will change from conductive material to dielectric ***,such composite is a good candidate for flexible conductive material or flexible dielectric material used in harsh environments such as high temperatures and various aggressive solvents.

关键词： Modified-MWCNTs Fluoroelastomer nanocomposite Interface compatibility Dielectric properties Volume resistivity

Polyarylene Ether Nitrile and Titanium Dioxide Hybrids as Thermal Resistant Dielectrics

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Chinese Journal of Polymer Science 2021年第2期39卷 211-218,I0007页

作者： Ren-bo Wei Chen-Hao Zhan Yang Yang Peng-Lin He xiao-bo liu Research Branch of Advanced Functional Materials School of Materials and EnergyUniversity of Electronic Science and Technology of ChinaChengdu 610054China School of Chemical Engineering Northwest UniversityXi’an 710069China

With the expanding application of capacitors,thermal resistant dielectric materials are in high demand due to the increasing harsh environments where the capacitors are needed and the heat generated by the ***,we present polyarylene ether nitrile and titanium dioxide hybrids which can be used as thermal resistant dielectrics for these *** modified titanium dioxide(TiO_(2)-CN)and phthalonitrile end-capped polyarylene ether nitrile(PEN-Ph)are firstly *** being cast into TiO_(2)-CN/PEN nanocomposite films,these composites self-crosslink upon heating at 320℃for 4 h,forming the polyarylene ether nitrile and titanium dioxide hybrids(TiO_(2)-PEN).Improved dielectric constants which are stable from room temperature to 200℃of these hybrids are observed,indicating the potential application of the hybrids as thermal resistant dielectrics.

关键词： Hybrid TiO2 Polyarylene ether nitrile Thermal resistance Dielectric properties

An Improved Car-Following Model for Multiphase Vehicular Traffic Flow and Numerical Tests

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Communications in Theoretical Physics 2006年第2X期46卷 367-373页

作者： LI Zhi-Peng GONG xiao-bo liu Yun-Cai Institute of Image Processing and Pattern Recognition Shanghai Jiaotong University Shanghai 200240 China

This paper attempts to introduce an improved difference model that modifies a car-following model, which takes the next-nearest-neighbor interaction into account. The hnprovement of this model over the previous one lies in that it performs more realistically in the dynamical motion for small delay time. The traffic behavior of the improved model is investigated with analytic and numerical methods with the finding that the new consideration could further stabilize traffic flow. And some simulation tests verify that the proposed model can demonstrate some complex physical features observed recently in real traffic such as the existence of three phases： free flow, coexisting flow, and jam flow; spontaneous formation of density waves; sudden flow drop in flow-density plane; traffic hysteresis in transition between the free and the coexisting flow. Furthermore, th.e improved model also predicts that the stable state to relative density in the coexisting flow is insusceptible to noise.

关键词： car-following models density waves traffic flow

Designing a Phthalonitrile/Benzoxazine Blend for the Advanced GFRP Composite Materials

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Chinese Journal of Polymer Science 2018年第1期36卷 106-112页

作者： Xu-Lin Yang Kui Li Ming-Zhen Xu xiao-bo liu Research Branch of Functional Materials Institute of Microelectronic & Solid State Electronic University of Electronic Science and Technology of China

High performance resin must be used in the high performance glass fiber-reinforced plastic（GFRP） composites, but it is sometimes difficult to balance the processabilities and the final properties in the design of advanced thermoset GFRP composites. In this study, a phthalonitrile/benzoxazine（PPN/BZ） blend with excellent processability has been designed and applied in the GFRP composite materials. PPN/BZ blend with good solubility, low melt viscosity, appropriate gel condition and low-temperature curing behavior could enable their GFRP composite preparation with the prepreg-laminate method under a relatively mild condition. The resulted PPN/BZ GFRP composites exhibit excellent mechanical properties with flexural strength over 700 MPa and flexural modulus more than 19 GPa. Fracture surface morphologies of the PPN/BZ GFRP composites show that the interfacial adhesion between resin and GF is improved. The temperatures at weight loss 5%（T_（5%）） and char residue at 800 °C of all PPN/BZ GFRP composites are over 435 °C and 65% respectively. PPN/BZ GFRP composites with high performance characteristics may find applications under some critical circumstances with requirements of high mechanical properties and high service temperatures.

关键词： Phthalonitrile Benzoxazine High performance composite GFRP composites

Vulnerability of premyelinating oligodendrocytes to white-matter damage in neonatal brain injury

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Neuroscience Bulletin 2013年第2期29卷 229-238页

作者： xiao-bo liu Yan Shen Jennifer M.Plane Wenbin Deng Department of Biochemistry and Molecular Medicine Institute for Pediatric Regenerative MedicineSchool of MedicineUniversity of California at Davis

Premature birth is a significant economic and public health burden, and its incidence is rising. Periventricular leukomalacia （PVL） is the predominant form of brain injury in premature infants and the leading cause of cerebral palsy. PVL is characterized by selective white-matter damage with prominent oligodendroglial injury. The maturation-dependent vulnerability of developing and premyelinating oligodendrocytes to excitotoxic, oxidative, and inflammatory forms of injury is a major factor in the pathogenesis of PVL. Recent studies using mouse models of PVL reveal that synapses between axons and developing oligodendrocytes are quickly and profoundly damaged in immature white matter. Axon-glia synapses are highly vulnerable to white-matter injury in the developing brain, and the loss of synapses between axons and premyelinating oligodendrocytes occurs before any cellular loss in the immature white matter. Microglial activation and astrogliosis play important roles in triggering white-matter injury. Impairment of white-matter development and function in the neonatal period contributes critically to functional and behavioral deficits. Preservation of the integrity of the white matter is likely key in the treatment of PVL and subsequent neurological consequences and disabilities.

关键词： prematurity neonatal brain injury white matter oligodendrocyte myelin periventricular leukomalacia

Study of catalytic effect of ammonium molybdate on the bisphthalonitrile resins curing reaction with aromatic amine

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Chinese Chemical Letters 2009年第3期20卷 348-351页

作者： Wen Ting Li Fang Zuo Kun Jia xiao bo liu Research Branch of Functional Materials State Key Laboratory of Electronic Films & Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China

A kind of catalyst, ammonium molybdate was developed in this paper to promote the curing reaction of bisphthalonitrile resins with aromatic amine as curing agent, and the catalytic effect was studied by differential scanning calorimetry （DSC）, rheometric measurements and thermogravimetric analysis （TGA）. The results indicated that the catalyst could improve the curing rate and increase the curing degree, which could be regulated by the content of the catalyst used in the reaction.

关键词： Bisphthalonitrile Catalyst Curing reaction Thermal stability

PEN/BADCy Interlayer Dielectric Films with Tunable Microstructures via an Assist of Temperature for Enhanced Frequency Stability

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Chinese Journal of Polymer Science 2020年第11期38卷 1258-1266,I0009页

作者： Xi-Ting Lei Li-Fen Tong Ming-Zhen Xu Yong You xiao-bo liu School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China

Low dielectric in terlayer films have become an important element to ensure the development of the microelectr onics industry.A kind of flexible interlayer dielectrics,polyarylene ether nitrile/bisphenol A cyanate ester(PEN/BADCy)film,with good thermal stability and low frequency dependence,has been developed by solution casting ***,materials were designed to incorporate bisphenol A cyanate ester as a part of blend,contributing to the frequency stability and structural *** morphological study combined with electron microscopy revealed the uniform and flexible microstructure information with controllable morphology through self-polymerization of cyanate esters with different prepolymerization time and curing *** dielectric films could present high thermal stability with Tg>180℃.Significant improvement in the dielectric properties was achieved for the dielectric constant and loss was much stabler than neat PEN over the frequency range from 100 Hz to 5 *** the prepolymerization time was 3h and final curing temperature reached 230℃,the dielectric constant and dielectric loss of the films were 3.36 and 0.013 at 100 kHz,*** dimensional stability(CTE=53.67×10^-6 K^-1)was confirmed and con sidered beneficial to use as an in terlayer dielectrics.

关键词： Polyarylene ether nitrile Bisphenol A cyanate ester Interlayer dielectrics Tunable microstructures

Poly(arylene ether nitrile)Dielectric Film Modified by Bi_(2)S_(3)/rGO-CN Fillers for High Temperature Resistant Electronics Fields

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Chinese Journal of Polymer Science 2022年第11期40卷 1441-1450页

作者： Li-Fen Tong Liang He Chen-Hao Zhan Yun-Qing Xia xiao-bo liu School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu610054China Sichuan Province Engineering Technology Research Center of Novel CN Polymeric Materials Chengdu610054China

High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric *** dielectric film is a crucial part of the film capacitor,and its properties have an important impact on the performance and use conditions of the film *** this work,a novel high-temperature-resistant dielectric film was ***,the Bi_(2)S_(3)/rGO-CN fillers were prepared by hydrothermal method combined with cyanation treatment,and then added to the poly(arylene ether nitrile)(PEN)matrix to prepare the dielectric film materials(PEN/Bi_(2)S_(3)/rGO-CN).After high temperature treatment,the fillers Bi_(2)S_(3)/rGO-CN reacted with the PEN matrix,and the composites materials transformed into a thermosetting hybrid film(PEN-Bi_(2)S_(3)/rGO)with gel content of 97.88%.The prepared hybrid dielectric films did not decompose significantly before 400℃,and showed a glass transition temperature(Tg)of up to 252.4℃,which could increase the effective use temperature of the *** with the composite films without heat treatment,they exhibit better mechanical properties,with further improvement in tensile strength and elastic modulus,and a decrease in elongation at *** dielectric constant of the hybrid films can be up to 6.8 while the dielectric loss is only about 0.02 at 1 ***,the hybrid films showed excellent dielectric stability during temperature changes,and remain relatively stable before 250℃,which is suitable as a high-temperature-resistant high-dielectric material and is more advantageous for practical applications.

关键词： Poly(arylene ether nitrile) Bismuth sulfide Graphene oxide High-temperature-resistant Dielectric properties

Effects of different statins application methods on plaques in patients with coronary atherosclerosis

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World Journal of Clinical Cases 2021年第4期9卷 812-821页

作者： Xia Wu xiao-bo liu Ting liu Wen Tian Yu-Jiao Sun Department of Geriatrics First Affiliated Hospital of China Medical UniversityShenyang 110001Liaoning ProvinceChina Department of Radiology First Affiliated Hospital of China Medical UniversityShenyang 110001Liaoning ProvinceChina

BACKGROUND Discontinued application of statins may be related to adverse cardiovascular ***,it is unclear whether different statins administration methods have effects on coronary artery *** To evaluate the effects of different statins application methods on plaques in patients with coronary *** A total of 100 patients diagnosed with atherosclerotic plaque by coronary artery computed tomography were continuously selected and divided into three groups according to different statins administration methods(discontinued application group,n=32;intermittent application group,n=39;sustained application group,n=29).The effects of the different statins application methods on coronary atherosclerotic plaque were *** The volume change and rate of change of the most severe plaques were significantly reduced in the sustained application group(P≤0.001).The volume change of the most severe plaques correlated positively with low-density lipoprotein(LDL-C)levels only in the sustained application group(R=0.362,P=0.013).There were no changes in plaques or LDL-C levels in the intermittent and discontinued application *** Continuous application of statins is effective for controlling plaque progression,whereas discontinued or intermittent administration of statins is not conducive to controlling *** with continuous statins administration can a reduction in LDL-C levels result in plaque volume shrinkage.

关键词： Coronary atherosclerotic plaque Statin Coronary artery computed tomography Low-density lipoprotein Plaque volume