COMPOSITES COMMUNICATIONS
·
2022
·
IF 7.685
Yongdong Wu,Chenxu Zhang,Wendian Tu,Guoping Du,Xiaoliang Zeng,Rong Sun,Yonglun Xu,Linlin Ren
The thermal conductivity and compliance of polymer-based thermal interface materials are typically associated and mutually exclusive: improving thermal conductivity usually requires high fillers content , but this sacrifices compliance. In this work, we propose a decoupling strategy via introducing pendent chains into polymer networks for the fabrication of thermal interface material with high thermal conductivity (4.50 W/m∙k) and excellent compliance (high stretchability of 104% and low Young's modulus of 0.24 MPa). The compliance of thermal interface material is improved with the pendent chain content increasing. The potential application of the resulting sample in chip cooling is demonstrated and the temperature is reduced by almost 24 °C in comparison to commercial TIMs. Our work presents a promising way for thermal interface materials design with high thermal conductivity and excellent compliance.
研究领域:
材料科学
·
热管理技术
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 32
·期 5
·2185-2196
·
IF 3.665
Jiang Xiaolin,Qin Rui,Wang Minhui,Xu Min,Sheng Yeming,Lu Xun
Aiming at the common problems of weak controllability of damping temperature range and poor mechanical properties in damping elastomer materials. Herein, we design a polyurethane-containing dynamic disulfide bonds and dangling chains to address this dilemma. The as-prepared polyurethane exhibits an unprecedented damping range of 182°C (−62 to 120°C), and the tensile strength reaches 6.8 MPa, which is at the forefront of the same type of research. We innovatively introduce aromatic disulfides to the system, in which disulfide bonds can be spontaneously exchanged dynamically at room temperature, making the damping performance of the elastomer above room temperature improved, and a small amount of hydroxyl-terminated polydimethylsiloxane (OH-PDMS) is used as a dangling chain to promote the damping property of the elastomer between the glass transition temperature and room temperature. The synergistic effect of disulfide bonds and dangling chains makes the controllability of polyurethane damping temperature range realized. Furthermore, polyurethane elastomer is equipped with good thermal stability duo to the introduction of OH-PDMS. And, the high-performance polyurethane elastomer has great potential in practical application.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2024
·
IF 4.8
Junhong Li,Yunsong Pang,Jun Wang,Min Yang,Xiaoliang Zeng,Linlin Ren,Rong Sun
The multifunctional composite elastomers serve as thermal interface materials for heat dissipation in electronic devices when their thermal transport performance is enhanced. The common method for enhancement, continuously raising the thermal conductive filler loading only can improve thermal conductivity of composite elastomers but reduces compliance, resulting in elevated contact thermal resistance with solid surfaces, compromising thermal transport. To address this, we propose grafting short dangling chains onto the composite elastomer matrix to further promote compliance under a certain filler loading. Characterization results demonstrate that the grafted chains effectively reduce relaxation time, enabling faster deformation for the material under pressure. This approach enhances interfacial compatibility, widening the thermal transport path at contact interfaces to contact thermal resistance by 94% (from 17.8 to 1.07 mm 2 W/K), significantly improving overall thermal transport. Additionally, we discussed the feasibility of employing composite elastomers as thermal interface materials for efficient chip heat dissipation. Highlight The grafted dangling chains can promote the composite elastomers softness. The softness promotion can help reduce thermal contact resistance. A series of theories are employed to learn the mechanisms of the promotion. The resulting composite elastomers can be used as thermal interface materials.
研究领域:
材料科学
·
热管理技术
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2023
·Vol. 61
·期 9
·748-760
·
IF 3.4
Li Wang,Haihang Luo,Qiang Gao,Le Jiang,Zhenya Wang,Haojun Fan,Yi Chen,Jun Yan,Jun Xiang
Bio-based polyols derived from vegetable oils generally contain the dangling chains, which have recently attracted significant attention due to their influence on the preparation and performance of the waterborne polyurethane. Herein, a novel undecylenic-based primary glycol (UPG) without dangling chains synthesized and the oleic-based primary glycol (OPG) with dangling chains reported by our previous work were used to prepare straight-chain and dangling-chain bio-based waterborne polyurethane (BWPU), respectively, to study the difference between the two diols and the effects of dangling chains on the synthesis and performance of BWPU. First, the UPG without dangling chains displayed higher activation energy ( E a / E o = 77.72/80.56 kJ mol −1 ) and longer reaction end point of prepolymer (240 min), indicating relatively lower reactivity to isocyanate. In addition, the dangling chains were found to influence the dispersion stability of BWPU, and the minimum dosage of DMPA for maintaining dispersion stability was 6.5 wt% for OPG but 5.5 wt% for UPG. The average particle size of BWPU is greater for OPG than for UPG with the same DMPA content. Finally, performance studies revealed that dangling-chain BWPU showed higher hydrophobicity, extensibility, and low temperature resistance, but lower thermal stability ( T d 5% ) and tensile strength. This work comprehensively clarified the effects of linear and branched bio-based polyols on the synthesis and properties of BWPU, and provided guidance for the development and application of bio-based polyols and BWPU coatings. Graphical
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Chenhao Xu,Li Li
Common microstructural features inspired by bones, including the moduli-mismatching interface and the intramolecular dangling chains, are employed in designing and fabricating our bio-inspired nanocomposite in order to defeat the conflict of stiffness versus damping. The epoxy vitrimer is itself chosen to construct the intramolecular dangling chains, and then mixed with multi-walled carbon nanotubes (MWCNTs) to form the moduli-mismatching interface. Experimental and theoretical research is performed to elucidate the role of the common microstructural features on the damping of our bio-inspired nanocomposite. Dangling chains improve damping, although they are negative for moduli. The high modulus of MWCNTs not only enlarges the modulus of composites but also causes a stress jump phenomenon at the interfacial zone, which induces the irreversible production process of inelastic strain at the interface to dissipate mechanical energy. The loss modulus of MWCNTs-reinforced epoxy nanocomposites is found to reach as much as 738 MPa, which exceeds the limit of 600 MPa for traditional materials (including bones), although the common microstructural features are inspired by bones. The synergistic enhancement mechanism caused by the intramolecular dangling chains and the moduli-mismatching interface is responsible for the surpassingly stiff yet lossy performances.
研究领域:
材料科学
·
仿生学
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2024
·
IF 4.5
Zheng Qiaoyang,Jiang Xiaolin,Lu Xun
Polyurethane elastomer has become a current focal point in the field of damping materials due to superior comprehensive properties. However, its effective damping temperature range is limited, and existing methods often lead to a reduction in mechanical performance. Moreover, polyurethane exhibits poor water resistance and flame resistance, constraining its applications. In this study, we introduce a small amount of dangling chain and aromatic dynamic disulfide bond into polyurethane to achieve a balance between damping and mechanical performance. Notably, the fluorinated dangling chain improves water resistance of the material synchronously and effectively. Additionally, ammonium polyphosphate modified by melamine and diethyl bis(2-hydroxyethyl)aminomethylphosphonate are introduced into polyurethane to improve flame resistance. The prepared polyurethane elastomer exhibits excellent comprehensive performance, featuring an effective damping (tanδ≥0.3) temperature range of 153.2 °C (−53.2 °C ∼ 100 °C), V-0 level flame resistance and excellent water resistance. Meanwhile, the heat stability of the polyurethane elastomer has been significantly enhanced, while maintaining a certain level of mechanical performance (9.72 ± 0.25 MPa, 602.4 ± 30.1%). These improvements extend the service life of polyurethane and expand its range of potential applications.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）