New ways to improve the damping properties in high‐performance thermoplastic vulcanizates

The incorporation of viscoelastic materials represents an effective strategy to reduce the vibratory level of structural components. Thermoplastic vulcanizates (TPVs) are a special type of viscoelastic material that combines the elastomeric properties of rubbers with the easy processing of thermoplastics. In the present work, we propose innovative ways to improve the damping properties of high‐performance TPVs by using rubbers with carboxylic functionalities. For that, TPVs from physical blends of carboxylated hydrogenated acrylonitrile butadiene rubber (XHNBR) and polyamide 6 (PA6) were prepared. The chain dynamics of different mixed crosslink systems containing peroxide, metal oxides and hindered phenolic antioxidants were investigated in order to find the most suitable strategy to design a high‐performance TPV system with upgraded damping properties. The results indicate that the damping performance of the TPV system can be tailored by controlling the type and magnitude of the bonding interactions between the mixed crosslink system and the XHNBR rubber phase. Therefore, this study demonstrates the potential of TPV systems containing carboxylic rubbers as high‐performance damping materials. © 2020 Society of Chemical Industry     

Effectiveness analysis and optimum design of the rotary regenerator for thermophotovoltaic (TPV) system

The influence of the period of rotation on the effectiveness of the thermophotovoltaic (TPV) rotary regenerator was theoretically and experimentally investigated.It was found that the deviations of the...     

热光伏系统性能匹配性研究

针对热光伏(TPV)系统建立了数值分析模型,研究了系统各模块的匹配特性,讨论了辐射器温度、散热器流速等性能参数对电池温度及输出功率的影响,并进行了优化组合分析,以获得系统最佳运行工况。结果表明:在每一特定辐射器温度下,都存在一最优散热器入口流速以使得系统效率达到最大。随着辐射器温度的升高,TPV系统效率及输出净功率均随之增大,但由于电池温度的升高,系统效率增长梯度逐渐减缓。当辐射温度达到1 800K时,系统效率最高可达到18.22%。     

Morphology Development in Novel Composition of Thermoplastic Vulcanizates Based on PA12/PDMS Reactive Blends

The main objective of the present work was to tailor a new thermoplastic vulcanisate (TPV) composed of PA 12 as the thermoplastic phase and PDMS as the rubber phase. The PDMS was crosslinked by dicumyl peroxide (DCP). Interestingly, addition of 2,2,6,6‐tetramethylpiperidinyloxyl (TEMPO) to the TPV provided the compatibilization of the PA12/PDMS blend in the dynamic process and gave a new material with control structure and morphology. The electron microscopy (SEM and TEM) studies revealed that adding silica nanoparticles and Lotader in PA12 and PDMS phases, respectively, led to a drastic reduction in R_v of the PDMS particles from 16.5 µm (virgin blend) to nearly 0.6 µm for the PA12/PDMS reactive blend. Therefore, a stable co‐continuous morphology was obtained for the new TPV based on 60–40 wt.‐% of PDMS‐PA12 blend.

     

热塑性弹性体的新进展

对近年来最热门的动态交联型热塑性弹性体（TPV），已在市场上见到的5类材料作了简要概述。对其中的聚苯乙烯类（TPS）的生产厂家和生产能力列表给出详细资料。我国是世界最大的TPE消费国，在生产和应用最有发展潜力的TPO（烯烃类）和TPV方面只是刚刚开始。     

EPDM/PP热塑性弹性体反应控制的研究

对EPDM／PPTPV的反应控制及反应控制与性能的关系进行了研究。结果表明，过氧化物(VD)，酚醛树脂(VP)，硫黄(Vs)体系均适宜作EPDM—E／PPTPV的硫化体系，而VD硫化体系在交联EPDM—D／PPTPV时有较快的硫化速度。TPV的反应速度随ENB含量、乙烯含量、DCP用量的增加而加快，也随反应温度和转速的提高而加快。在研究范围内，由反应温度引起的速度对力学性能的贡献最大，其次为转速引起的速度，再次为交联剂引起的速度，且3因素引起的速度与拉伸强度和拉断伸长率之间有最佳值。     

分子束外延生长的GaSb热光伏电池器件特性研究

利用分子束外延的方法在GaSb衬底上生长GaSb热光伏电池单元,制作了两种不同的1 cm×1 cm面积尺寸的热光伏电池单元,它们有着不同的电极形状。通过不断优化分子束外延的生长条件,以期得到高质量的GaSb外延层。AFM图中显示的表面形貌表明器件有着高质量的外延层,其表面形貌的RMS只有1.5 ? （1 ?=0.1 nm）。测量和比较了两种热光伏电池的器件特性,包括开路电压、短路电流密度、光电转换效率、填充因子以及暗电流密度。在一个模拟太阳光照射下,热光伏电池单元有着0.303 V的开路电压和27.1 mA/cm2的短路电流密度。和只有简单电极形状的热光伏电池单元进行对比,有栅形电极形状的热光伏电池单元在短路电流密度和填充因子上具有更优异的表现。在红外光的照射下,有栅形电极形状的热光伏电池达到了一个最优的填充因子56.8%。     

低硬度动态硫化EPDM/PP TPV的开发

研究了橡胶/塑料/填充油比例（R/P/O）、树脂硫化体系对低硬度动态硫化三元乙丙橡胶（EPDM）/聚丙烯（PP）热塑性硫化橡胶（TPV）的硬度和力学性能的影响.获得配方（质量份,橡胶为100份）为：PP为30份;油为80份;酚醛树脂用量为6份;SnCl2为1份.其力学性能为邵尔硬度55 A;拉伸强度6.12 MPa、断裂伸长率553%;达到国外同类产品水平.     

Effect of spatial confinement on the development of β phase of polypropylene

The focus of this study was the effect of spatial confinement on the development of nucleating agent-induced β phase polypropylene (PP) in the dynamically vulcanized thermoplastic elastomers (TPVs) based on dynamically vulcanized PP/ethylene-propylene-diene rubber (EPDM) blend. The melting behaviors, crystalline structures and the morphologies of the blends were studied by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The results indicate that the EPDM phase undergoes a series of changes from the dispersed phase to a continuous one, and again to the dispersed phase with increased content of curing agent, and the PP component always shows itself in a continuous phase. In this process, with the content of the nucleating agent unchanged, the content of β phase PP in the blends initially increases a little and then decreases with increasing PF (Phenolic resin) content. We believe spatial confinement provides a good explanation for the development of β phase PP.     

国内外汽车用热塑性弹性体材料的发展现状

综述了国内外汽车用热塑性弹性体材料的发展现状。包括TPO在保险杠、仪表盘等的应用;TPV在门窗密封条、窗玻璃槽角件等的应用;TPEE在等速万向节护套、各种护罩等的应用;TPU在减震垫、各种轴套等的应用;TPS材料在胶管、密封垫等的应用。为了响应汽车环保、轻量化的发展趋势,我国应创造条件,使汽车用热塑性弹性体材料向高性能化、专用化和本土化方向发展。