Research Progress of Thermal Conductive Plastics on High Thermal Conductivity

In this paper, the research progress of thermal conductive plastics at present is summarized from the categories of thermal conductive plastics, the advantages of thermal conductive plastics over other thermal conductive materials, several common preparation methods of thermal conductive plastics and the key problems in future research.The problems found in the process of summarizing are discussed and prospected.

CHARACTERISTICS OF CATION—CONDUCTIVE BLENDS PLASTICIZED WITH PROPYLENE CARBONATE

The cation—conductive blends plasticized with propylene carbonate were prepared. The blends exhibited good mechanical strength and single—cation conduction over a wide range of plasticizer composition. The plasticizer not only increases the conductivity of the blends but also decreases the electrochemical interface resistance between the blend and lithium electrode. The carrier in the blends obviously grows in number.

Effects of Metal Absorber Thermal Conductivity on Clear Plastic Laser Transmission Welding

In our previous study, metals have been used as absorbers in the clear plastic laser transmission welding. The effects of metal thermal conductivity on the welding quality are investigated in the present work. Four metals with distinctly different thermal conductivities, i.e., titanium, nickel, molybdenum, and copper, are selected as light absorbers. The lap welding is conducted with an 808 nm diode laser and simulation experiments are also conducted. Nickel electroplating test is carried out to minimize the side-effects from different light absorptivities of different metals. The results show that the welding with an absorber of higher thermal conductivity can accommodate higher laser input power before smoking, which produces a wider and stronger welding seam.The positive role of the higher thermal conductivity can be attributed to the fact that a desirable thermal field distribution for the molecular diffusion and entanglement is produced from the case with a high thermal conductivity.

STUDY ON THE CONDUCTING FIBER REINFORCED PLASTIC

The conductive fiber reinforced plastic was prepared by dispersing electrical conducting filler particles such as aluminum powder, graphite and carbon black to glass fiber reinforced resin. The effects that each or double kinds of fillers, also the conductive fiber cloth had done on the electrical and mechanical properties of plastic composites were studied. This paper also provided discussion on the conductive mechanism of fiber reinforced plastic. (Author abstract) 8 Refs.

Study on improvement of conductivity of Cu-Cr-Zr alloys

The influence of alloying, heat treatment, and plastic working on the performance of Cu-Cr-Zr alloys was investigated. The precipitated phases were characterized as Cr, Cu51Zr14 and Cu5Zr. Cu-Cr-Zr alloys demonstrate combination properties of high strength and high conductivity after solution treatment, aging treatment, and plastic deformation. Precipitation course of Cr is the main factor that influences the conductivity of Cu-Cr-Zr alloys, while adding Zr in the alloys adjusts the orientation relationship between Cr and matrix, and tends to increase the conductivity of aged Cu-Cr-Zr alloys after deformation.

Quasi-solid-state polymer plastic crystal electrolyte for subzero lithium-ion batteries

Succinonitrile(SN)-based polymer plastic crystal electrolytes(PPCEs)have attracted considerable attention as solid-state electrolytes owing to their high ionic conductivities similar to those of liquid electrolytes,excellent contacts with the electrodes,and good mechanic properties.As a crucial property of a solid-state electrolyte,the ionic conductivity of the PPCE directly depends on the interactions between the constituent parts including the polymer,lithium salt,and SN.A few studies have focused on the effects of polymer–lithium–salt and polymer–SN interactions on the PPCE ionic conductivity.Nevertheless,the impact of the lithium–salt–SN combination on the PPCE ionic conductivity has not been analyzed.In particular,tuning of the lithium-salt–SN interaction to fabricate a subzero PPCE with a high low-temperature ionic conductivity has not been reported.In this study,we design and fabricate five PPCE membranes with different weight ratios of Li N(SO2 CF3)2(Li TFSI)and SN to investigate the effect of the Li TFSI–SN interaction on the PPCE ionic conductivity.The ionic conductivities of the five PPCEs are investigated in the temperature range of–20 to 60°C by electro-chemical impedance spectroscopy.The interaction is analyzed by Fourier-transform infrared spectroscopy,Raman spectroscopy,and differential scanning calorimetry.The Li TFSI–SN interaction significantly influences the melting point of the PPCE,dissociation of the Li TFSI salt,and thus the PPCE ionic conductivity.By tuning the Li TFSI–SN interaction,a subzero workable PPCE membrane having an excellent low-temperature ionic conductivity(6×10-4 S cm–1 at 0°C)is obtained.The electro-chemical performance of the optimal PPCE is evaluated by using a Li Co O2/PPCE/Li4 Ti5 O12 cell,which confirms the application feasibility of the proposed quasisolid-state electrolyte in subzero workable lithium-ion batteries.

Discrete Model of Plasticity and Failure of Crystalline Materials

Within the framework of a discrete model of the nuclei of linear and planar defects, the variational principles of sliding in translational and rotational plasticity, fracture by separation (cleavage) and shear (shearing) in crystalline materials are considered. The analysis of mass transfer fluxes near structural kinetic transitions of slip bands into cells, cells into fragments of deformation origin, destruction by separation and shear for fractal spaces using fractional Riemann-Liouville derivatives, local and global criteria of destruction is carried out. One of the possible schemes of the crack initiation and growth mechanism in metals is disclosed. It is shown that the discrete model of plasticity and fracture does not contradict the known dislocation models of fracture and makes it possible to abandon the kinetic concept of thermofluctuation rupture of interatomic bonds at low temperatures.

Effect of Polyethylene Terephthalate Plastic Waste on the Physico-Mechanical and Thermal Characteristics of Stabilized Laterite Bricks

The present work investigated the effect of polyethylene terephthalate (PET) plastic waste on the physico-mechanical and thermal properties of cement-stabilized laterite bricks to see the durability of the modified bricks (CSLB). Samples were formulated by mixing laterite, cement, and different percentages of PET (0%, 3%, 5%, and 7%) by volume. The bricks were produced using the M7MI Hydraform standard interlocking block and kept in the shade for a curing period of 28 days. The addition of 3% to 5% PET to the laterite stabilized with 10% cement results in a decrease in both dry and wet compressive strength, which is determined using the Controlab compression machine. However, the obtained results are in concordance with the standards. The thermal conductivity of CSLB, determined using the box method with the EI700 measurement cell, decreases as the PET content of the mixture increases. A decrease in bulk density from 1.67 to 1.58 g/cm3 was observed.

黏结性富油煤热解油气析出规律及物性演变特征

黏结性富油煤受热产生的软化、熔融现象可能导致井筒堵塞和地层扰动,这是原位热解需考虑的重要因素。在300~700℃下对黏结性富油煤热解,考察油气析出规律和组成性质,分析半焦的物性演变特征及其对原位热解的指示意义。结果表明,焦油产率在500℃取得最大值7.75%,此时<300℃轻质组分含量最高(32.2%),且焦油成分在400~500℃变化显著,酚类和芳烃含量分别呈现增大和降低趋势。煤样的软化温度和固化温度分别为389和455℃,使半焦的宏观孔率度在≥400℃时由不足10%增至约50%,而微观孔隙结构仅在600~700℃高温脱气阶段更发达;半焦导热系数随温度先减小后增大,并在400℃达到最小值0.06 W/(m·℃)。黏结性富油煤原位热解面临通道堵塞、挥发分析出受阻和煤层导热速率偏慢等潜在问题,可尝试采用具有破黏效应的压裂支撑剂或近临界水原位转化技术加以解决。

三重热管理塑木复合板的制备及性能

塑木复合材料因其显著的性能优势,已被广泛应用于各领域。但户外用塑木复合板在夏季的表面温度过高,存在热舒适性差的问题。本文通过熔融共混/模压成型的工艺制备了一种可被动降温的辐射/反射/导热三重热管理功能的塑木复合板,以高密度聚乙烯(HDPE)为基体,分别在面层和底层加入二氧化锆(ZrO2)和六方氮化硼(h-BN)以实现热量的三重调控。面层薄膜在太阳波段(0.3~2.3μm)和中红外大气窗口波段(8~13μm)的平均反射率和平均发射率分别达到82.6%和90.6%,加颜料后达到了48.7%的平均反射率和90.6%的平均发射率;底层塑木复合板的面内和垂直导热系数分别为1.89 W/(m·K)和1.71 W/(m·K)。双层复合后的三重热管理功能塑木复合板在户外和室内氙灯模拟测试中可分别达到7.2℃和15℃的温降效果,具有显著的散热优势,可广泛应用于户外塑木复合板的被动降温。

双螺杆挤出机塑化系统电磁加热过程的数值模拟与实验研究及应用

探究电磁加热相比于铸铜加热对双螺杆挤出机塑化系统的影响,首先针对现有双螺杆机筒和线圈分布建立几何模型,使用comsol有限元软件研究了电磁加热过程机筒磁通量变化以及温度均匀性;另外,在数值模拟的指导下开展具体试验验证,对比了电磁加热和铸铜加热的机筒内壁及法兰温度均匀性、用电量及电磁辐射安全性。结果表明,电磁加热具有更高的控温精度,保证温度均匀性在±1℃以内,与模拟结果相吻合;在相同的加热时间内,电磁加热可以实现机筒和法兰同步加热,预热时间节约40%,生产过程节能50%;另外电磁辐射符合国家安全标准(GB 8702—2014),保证车间工人的人身安全。

PP&PE杂化材料用水性抗静电涂料的研制

以自制烯烃改性磺酸盐型水性聚氨酯为主体树脂,引入高Tg值水性氯化聚丙烯树脂作为改性树脂,通过添加复合导电颜填料和单壁碳纳米管,制备了PP&PE杂化材料用功能型水性抗静电涂料。该产品以水分为散介质,施工工艺简单,常温即可固化,是节能环保型产品;固化后形成的涂层在PP&PE杂化材料上附着力突出,机械强度高,具有持久、稳定的低电阻(≤105Ω)特性,可有效增加基材表面硬度和抗划伤能力,增强其耐候性,能够及时有效地消除材料表面的静电积累,防止静电火灾和静电爆炸的发生,保障生产经营安全。

电渗真空预压联合加固施工工法应用分析

为解决我国沿海及内陆湖泊流域等地分布的吹填地基和软黏土地基存在的问题,文章以电渗真空预压联合加固技术为基础,通过改进排水方式,提高软土地基固结速度和土体强度,形成了一种有效的施工工法。该工法是由导电塑料排水板、导电线路、直流电源、电渗控制电柜和真空泵组成的系统,兼顾了电渗法和真空预压法的优势。经实际工程应用验证,该技术能显著改善土体物理力学指标,提高软土地基承载力和排水性能,加快地基固结速率,同时具有良好的经济效益和环保效益。

绝缘导热高分子复合材料研究

介绍了导热绝缘高分子复合材料的导热性能、导热机理,综述了各类导热绝缘高分子如复合型导热塑料、橡胶、胶粘剂、涂层等的研究,并展望了其应用前景及未来发展方向。

导热高分子复合材料的研究与应用

概述了导热高分子材料的应用开发背景 ,描述了近几年来导热塑料、胶粘剂和橡胶领域内的研究开发进展。

回收烟气余热的特种耐腐蚀塑料换热器的性能分析

运用特种塑料材料的换热器可以解决烟气余热回收中的低温腐蚀问题,扩大热回收的温度范围。结合1000MW机组烟气余热回收工况,分析了氟塑料管束式换热器和导热塑料翅片管换热器的性能,比较了两者在传热系数、换热面积、换热器体积、流动阻力等方面的差异。尽管氟塑料换热器在传热系数和材料消耗方面具有优势,但翅片管换热器整体体积更小,且管件数量远小于氟塑料换热器。在此基础分析了污垢热阻和材料热导率对翅片管换热器的影响,发现污垢热阻会造成换热器性能20%~30%的变化,材料热导率则需要达到15~20W/（m？K）的阈值,才能实现较好的换热性能。

导热高分子材料的研究开发现状

综述了近几年来导热高分子材料主要是导热塑料、导热橡胶领域内的研究开发进展。简单阐述了导热高分子材料的导热机理及导热理论模型,在此基础上探讨了优化导热高分子材料综合性能的途径。

复合型导电塑料中导电填料的开发现状与发展

综述了复合型导电塑料中导电填料的种类及其特性,介绍了导电填料的选择原则,并探讨了导电填料的发展方向。

导热塑料研究进展

介绍导热绝缘及导热非绝缘塑料的导热性能、导热机理及导热填料粒子表面处理研究概况 ,并介绍了导热塑料的成型工艺条件选择及优化。综述了各类导热塑料的研究进展 ,讨论了提高塑料导热性能的途径 ,并展望了其应用前景。