检索结果-南通市图书馆

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

引用

Chinese Journal of polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong Wu Qiang Fu State Key Laboratory of polymer materials engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of polymer materials engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Creep-Resistant Covalent Adaptable Networks with Excellent SelfHealing and Reprocessing Performance via Phase-Locked Dynamic Covalent Benzopyrazole-Urea Bonds

引用

Chinese Journal of polymer Science 2024年第10期42卷 1545-1556页

作者： Miao Xie Xiao-Rong Wang Zhan-Hua Wang He-Sheng Xia State Key Laboratory of polymer materials engineering Polymer Research InstituteSichuan University School of Petrochemical engineering Liaoning Petrochemical University

Covalent adaptive networks (CANs) are capable of undergoing segment rearrangement after being heated, which endows the materials with excellent self-healing and reprocessing performance, providing an efficient solution to the environment pollution caused by the plastic wastes. The main challenge remains in developing CANs with both excellent reprocessing performance and creep-resistance property. In this study, a series of CANs containing dynamic covalent benzopyrazole-urea bonds were developed based on the addition reaction between benzopyrazole and isocyanate groups. DFT calculation confirmed that relatively low dissociation energy is obtained through undergoing a five-member ring transition state, confirming excellent dynamic property of the benzopyrazole-urea bonds. As verified by the FTIR results, this nice dynamic property can be well maintained after incorporating the benzopyrazole-urea bonds into polymer networks. Excellent self-healing and reprocessing performance is observed by the 3-ABP/PDMS elastomers owing to the dynamic benzopyrazole-urea bonds. Phase separation induced by the aggregation of the hard segments locked the benzopyrazole-urea bonds, which also makes the elastomers display excellent creep-resistance performance. This hard phase locking strategy provides an efficient approach to design CANs materials with both excellent reprocessing and creep-resistance performance.

关键词： Covalent adaptive networks Dynamic covalent bond Self-healing polymer

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

3D printing encouraging desired in-situ polypyrrole seed-polymerization for ultra-high energy density supercapacitors

引用

Journal of Energy Chemistry 2024年第8期95卷 117-125,I0004页

作者： Tiantian Zhou Shangwen Ling Shuxian Sun Ruoxin Yuan Ziqin Wu Mengyuan Fu Hanna He Xiaolong Li Chuhong Zhang State Key Laboratory of polymer materials engineering Polymer Research InstituteSichuan UniversityChengdu 610065SichuanChina

The tireless pursuit of supercapacitors with high energy density entails the parallel advancement of wellsuited electrode materials and elaborately engineered ***(PPy)emerges as an exceedingly conductive polymer and a prospective pseudocapacitive materials for supercapacitors,yet the inferior cyclic stability and unpredictable polymerization patterns severely impede its real-world ***,for the first time,an innovative seed-induced in-situ polymerization assisted 3D printing strategy is proposed to fabricate PPy-reduced graphene oxide/poly(vinylidene difluoride-cohexafluoropropylene)(PVDF-HFP)(PPy-rGO/PH)electrodes with controllable polymerization behavior and exceptional areal mass *** preferred active sites uniformly pre-planted on the 3D-printed graphene substrates serve as reliable seeds to induce efficient polypyrrole deposition,achieving an impressive mass loading of 185.6 mg cm^(-2)(particularly 79.2 mg cm^(-2)for polypyrrole)and a superior areal capacitance of 25.2 F cm^(-2)at 2 mA cm^(-2)for a 12-layer *** agreement with theses appealing features,an unprecedented areal energy density of 1.47 mW h cm^(-2)for a symmetrical device is registered,a rarely achieved value for other PPy/rGO-based *** work highlights a promising route to preparing high energy density energy storage modules for real-world applications.

关键词： 3D printing Seed-induced polymerization Supercapacitor Polypyrrole High energy density

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An Effective Approach for the Preparation of High Performance Thermal Conductive polymer Composites Containing Liquid Metal

引用

Chinese Journal of polymer Science 2024年第7期42卷 992-1001,I0010页

作者： Xin Chen Xue-Zhong Zhang Yi-Fei Yuan Chuan-Liang Chen Lian-Hu Xiong Qiang Fu Hua Deng College of polymer Science and engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China Department of materials Science and engineering Sichuan University-Pittsburgh InstituteSichuan UniversityChengdu610065China

The preparation of high-performance thermal conductive composites containing liquid metals(LM)has attracted significant ***,the stable dispersion of LM within polymer solution and effective property contribution of liquid metals remains significant challenges that need to be *** by the properties of the dendritic structure of the tree root system in grasping the soil,“shear-induced precipitation-interfacial reset-reprotonation”processing strategy is proposed to prepare nanocomposites based on aramid micron fibers(AMFs)with hierarchical dendritic *** to the combination of van der Waals force provided by hierarchical dendritic structure,electrostatic interaction between AMFs and LM,coordinative bonding of―NH to LM,together with interfacial re-setting and multi-step protonation,several features can be achieved through such strategy:conducive to the local filler network construction,improvement of interfacial interaction,improvement of the stability of filler dispersion in the solvent,and enhancement of mechanical and thermal properties of the *** resulting AMFsp H=4/LM films demonstrate a thermal conductivity of 10.98 W·m^(-1)·K^(-1)at 70%filler content,improvement of 126.8%compared to ANFs/LM film;while maintaining a strength of~85.88 MPa,improvement of 77%compared to AMFs/LM *** also possess insulation properties,enable heat dissipation for high power *** work provides an effective strategy for the preparation of high performance polymer composites containing liquid metal.

关键词： Shear-induced Reprotonation AMFs LM Filler dispersion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In situ protonation in a locally flexible porous coordination polymer for enhancing proton-carrier loading and proton conductivity

引用

Science China Chemistry 2024年第10期67卷 3432-3437页

作者： Xianzhe Wei Jincheng Liu Yan Su Weitao Wang Guixiang Wang Gen Zhang Ping Wang Cheng Gu State Key Laboratory of Luminescent materials and Devices Institute of Polymer Optoelectronic Materials and DevicesSouth China University of Technology College of polymer Science and engineering State Key Laboratory of Polymer Materials EngineeringSichuan University Key Laboratory for Soft Chemistry and Functional materials of Ministry of Education School of Chemistry and Chemical EngineeringNanjing University of Science and Technology

Designing efficient proton-conductive materials is crucial in fuel cells. Yet, it remains a substantial challenge because of the issues in proton mobility, proton-carrier amount, and orientation of proton host materials. Herein, we report an in-situ protonation strategy to produce a locally flexible porous coordination polymer(PCP) to enhance the proton-carrier loading and proton conductivity. The local dipole flipping of the ligand allows effective proton exchange with low activation energy, promoting interpore proton transport through the pore apertures and pore walls. The protonation induces substantial charges to the frameworks and enhances the interaction with proton carriers, thereby increasing the loading of the proton carriers. By this design strategy, the resulting PCP exhibits enhanced phosphoric acid loading and extraordinary proton conductivities under both aqueous and anhydrous conditions compared to its isoreticular analog that features rigidity without proton-exchange *** work provides a new avenue for designing proton-conductive materials that combine structural dynamics with performance merits.

关键词： porous coordination polymers in-situ protonation local flexibility proton-exchange mechanism proton conduction

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Highly Stretchable and Tunable Thermo-fluorochromic polymer Elastomer through Eu3+ Dynamic Coordination Cross-linking

引用

Chinese Journal of polymer Science 2024年第10期42卷 1449-1458页

作者： Qiu-Li Tan Kai Gou Jing-Zhi Tang Ming-Hui Wei Chong Wang Yi-Jing Nie Geng-Sheng Weng School of materials Science and Chemical engineering State Key Laboratory Base of Novel Functional Materials and Preparation Science Ningbo University institute of polymer materials School of Materials Science and Engineering Jiangsu University

Thermochromic polymers with tunable thermochromism, high stretchability and mechanical strength are of interests for optical information storage and encryption. In this work, we demonstrate a new design of thermo-fluorochromic carboxylated nitrile butadiene rubber(XNBR) elastomer cross-linked by Eu3+-COOH dynamic coordination with deprotonated imidazole (DPIm) as the ancillary ligand. The presence of DPIm not only improves the mechanical strength and stretchability, but also dramatically intensifies the fluorescence emission and lifetime of the Eu-containing elastomer. The elastomer behaves reversible thermo-fluorochromism with easily tunable transition temperature and emission intensity by the simple change of the deprotonation degree of imidazole. The facile tunable thermo-fluorochromism, exceptional mechanical strength, and high stretchability (up to about 5000%) enable the Eu-containing XNBR elastomer with potential applications in soft electronics where optical information storage and encryption are required.

关键词： Dynamic coordination Elastomer Europium Highly stretchable Thermochromism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Celebrating the 70th anniversary of the establishment of the polymer science discipline at Sichuan University

引用

SusMat 2024年第1期4卷 2-3页

作者： Qi Wang Chuhong Zhang State Key Laboratory of polymer materials engineering Polymer Research Institute of Sichuan UniversityChengduChina

The polymer science discipline at Sichuan University(SCU)was founded in 1953 by *** Xu,one of the pioneers in polymer materials science and engineering in China and honored as the“Father of Chinese Plastics,”who was also an academician of the Chinese Academy of *** a glorious 70-year journey,polymer science at SCU has evolved into a top-notch,globally recognized,and the largest research and teaching center in the realm of polymer science and engineering in *** the occasion of the 70th anniversary of the establishment of the polymer science discipline at SCU,we extend our deepest gratitude to the visionary founders and every indi-vidual who has contributed to the development of this discipline.

关键词： polymer globally 70t

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tunable Phase Structure of Side-chain Liquid Crystalline polymers Enabled by Molecular engineering of Dual Mesogenic Cores

引用

Chinese Journal of polymer Science 2024年第10期42卷 1459-1469页

作者： Wen-Huan Yao Lan-Sheng Liu Jie Zhao Yan-Xia Wang An-Zhi Ma Zheng-Rui Ma Lan-Ying Zhang Ruo-Chen Lan College of Chemistry and Chemical engineering Hunan University Key Laboratory of Eco-Functional polymer materials of the Ministry of Education Key Laboratory of Eco-Environmental Polymer Materials of Gansu ProvinceCollege of Chemistry and Chemical Engineering Northwest Normal University Department of materials Science and engineering College of Engineering Peking University institute of Advanced materials & Key Lab of Fluorine and Silicon for Energy materials and Chemistry of Ministry of Education College of Chemistry and Chemical Engineering Jiangxi Normal University

A series of novel side-chain liquid crystalline (SCLC) copolymers were synthesized by attaching two distinct mesogenic units, namely a chiral cholesteryl-based monomer (M1) and an achiral biphenyl-based monomer (M2), to a poly(3-mercaptopropylmethylsiloxane)(PMMS) backbone via thiol-ene click chemistry. The influence of side chain composition on the self-assembly behavior and phase structures of these SCLC copolymers was systematically investigated using different instrument. Results indicate that three distinct liquid crystalline phases and four unique molecular configurations were identified within the polymer series, with the emergence of the liquid crystalline phase being a synergistic outcome of the two distinct side chains. This study underscores the critical influence of side chain dimensions, rigidity, and spatial volume on the self-assembly structures and phase characteristics of liquid crystalline polymers, providing valuable insights for the rational design and development of advanced functional materials with tailored properties.

关键词： Chiral molar ratio Liquid crystalline copolymers Phase structure Self-assembly

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Regulating photothermal properties of near-infrared croconaine dyes by supramolecular assembly

引用

Nano Research 2024年第9期17卷 8560-8570页

作者： Yangge Ren Yue Lu Juanjuan Gao Yi Ding Bo Zhu Xinyu Hou Lin Jia Department of polymer materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Department of Electronic Information materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The photochemical and photophysical properties of near-infrared(NIR)dyes are significantly influenced by their aggregation state and mesoscopic ***,beyond chemical synthesis,the regulation mechanisms for the properties of NIR dyes,particularly with respect to photothermal properties of the aggregates,are not yet fully ***,we investigate the photothermal behaviors of croconaine-based(CroA)NIR dyes containing dipeptide or amino acids *** introduction of hydrogen bonding promotesπ-πstacking of croconaine center,which can efficiently regulate aggregation states and assembly structures in *** laser irradiation,CroA aggregates undergo aggregation-dissociation transition,the in-situ monomer generation process regulates two parameters of photothermal performance:heating rates and plateau photothermal *** study reveals the regulation effect of non-covalent bonding interactions on CroA aggregates,highlighting supramolecular assembly strategy not only facilitates to construct of photothermal nanomaterials with well-defined structures,but also provides an alternative and effective method for regulating photothermal performance of NIR dyes.

关键词： croconaine dye hydrogen bonding photothermal performance supramolecular assembly chirality

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Understanding the Thermal Impedance of Silicone Rubber/Hexagonal Boron Nitride Composites as Thermal Interface materials

引用

Chinese Journal of polymer Science 2024年第3期42卷 352-363,I0008页

作者： Yuan Ji Shi-Da Han Hong Wu Shao-Yun Guo Feng-Shun Zhang Jian-Hui Qiu The State Key Laboratory of polymer materials engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China institute of Chemical materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials Hexagonal boron nitride Thermal impedance Surfaces

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：