發(fā)布時間：2018-04-20 06:21

  本文選題：直流電纜 + 等規(guī)聚丙烯�。� 參考：《高電壓技術(shù)》2017年11期

【摘要】：聚丙烯(PP)不僅具有良好的電氣性能和耐熱性能,而且在壽命終止后可循環(huán)利用,有可能替代交聯(lián)聚乙烯(XLPE)作為電纜絕緣材料。因而通過研究乙烯 丙烯嵌段共聚聚丙烯(EPC)和等規(guī)均聚聚丙烯(iPP)的微觀結(jié)構(gòu)、力學(xué)沖擊強度和電學(xué)性能,探討了EPC作為高壓直流電纜絕緣材料的潛力。結(jié)果表明:iPP和EPC中只有α球晶,EPC中的α球晶較iPP中的小而密集,球晶之間沒有明顯的界面,球晶生長速度慢,但總結(jié)晶速度快。在不同溫度下的非等溫結(jié)晶過程中,EPC的結(jié)晶度低,熔點高。同時EPC中嵌段共聚的乙烯分子鏈片段形成橡膠態(tài)結(jié)構(gòu),顯著提高了其抗沖擊強度,低溫脆化溫度可達(dá) 57.3℃,遠(yuǎn)低于iPP的 5℃。EPC的常溫體積電阻率和直流擊穿場強低于iPP,但隨溫度升高其體積電阻率和擊穿場強的穩(wěn)定性高于iPP。在90℃,iPP和EPC的直流擊穿場強分別下降了27%和21%,體積電阻率分別下降了128.8×10~(15)?·cm和52.5×10~(15)?·cm。在40 kV/mm下,iPP積聚的空間電荷密度約為EPC的3倍,因而EPC更適用于擠出型高壓直流電纜絕緣料。EPC性能的改善均與其相態(tài)結(jié)構(gòu)和微觀晶體結(jié)構(gòu)有關(guān)。
[Abstract]:Polypropylene (PP) not only has good electrical properties and heat resistance, but also can be recycled after the end of life. It may be used as a cable insulation material instead of XLPE. Therefore, the potential of EPC as insulation material for HVDC cables is discussed by studying the microstructure, mechanical impact strength and electrical properties of ethylene / propylene block copolymerized polypropylene (EPC) and isotactic polypropylene (IPP). The results show that only 偽 -spherulites in EPC and EPC are smaller and denser than those in iPP. There is no obvious interface between spherulites, and the growth rate of spherulites is slow, but the total crystallization rate is fast. In the process of non isothermal crystallization at different temperatures, the crystallinity of EPC is low and the melting point is high. At the same time, the block copolymerized segments of ethylene molecules in EPC formed rubber structure, which significantly improved its impact strength, and the embrittlement temperature reached 57.3 鈩，

本文編號：1776624