退火速率对环保型聚乳酸材料直流击穿和电导电流特性的影响  

Effect of Annealing Rate on DC Breakdown and Conduction Current Characteristics of Environmentally Friendly Poly-Lactic Acid Material

作　　者：李科 张云霄[2] 周远翔 张灵[2] 滕陈源[2,3] Li Ke;Zhang Yunxiao;Zhou Yuanxiang;Zhang Ling;Teng Chenyuan(The Wind Solar Storage Division of State Key Lab of Control and Simulation of Power System and Generation Equipment School of Electrical Engineering Xinjiang University,Urumqi 830047 China;State Key Lab of Control and Simulation of Power System and Generation Equipment Department of Electrical Engineering Tsinghua University,Beijing 100084 China;School of Electrical Engineering Wuhan University,Wuhan 430072 China)

机构地区：[1]电力系统及大型发电设备安全控制和仿真国家重点实验室风光储分室(新疆大学电气工程学院),乌鲁木齐830047 [2]电力系统及大型发电设备安全控制和仿真国家重点实验室(清华大学电机系),北京100084 [3]武汉大学电气与自动化学院,武汉430072

出　　处：《电工技术学报》2020年第24期5041-5049,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51907101,51977186);中国科协青年人才托举工程(2018QNRC001);中国博士后科学基金面上(2019M650029);新能源电力系统国家重点实验室开放课题(LAPS19004)资助项目。

摘　　要：聚乳酸(PLA)是一种绝缘性能良好、可生物降解的环保型聚合物材料。为研究退火速率对PLA直流击穿和电导电流特性的影响,该文制备三种退火速率的PLA试样,即冰水冷却(PLA-W)、空气冷却(PLA-A)和缓慢冷却(PLA-S),并针对温度场下PLA的直流击穿及电导电流特性展开研究。结果表明:PLA-S直流击穿场强最高,温度从30℃升至70℃,三种试样的直流击穿场强下降,PLA-S降幅最小,仅为16.7%。PLA-S的电导率随温升而单调上升,PLA-A和PLA-W的电导率呈现上升-下降-上升的趋势。结合差示扫描量热和偏光显微观测发现,缓慢退火促进PLA结晶,晶胞尺寸大且均匀性好,PLA-S的结晶度达50%,玻璃化转变温度较PLA-W提升23.7%;PLA-W和PLA-A结晶不完善,温升过程出现晶胞生长或成核结晶,结晶度提高以致电导率呈上升-下降-上升趋势。Poly-lactic acid(PLA)is a biodegradable environmentally friendly polymer material with good insulation properties.In order to study the effect of the annealing rate on the DC breakdown and conduction current characteristics of PLA,PLA samples with three annealing rates were prepared,namely slow-cooled(PLA-S),air-cooled(PLA-A)and ice-water cooled(PLA-W).DC breakdown and conduction current characteristics of PLA were tested at temperature fields.The results show that DC breakdown strength of PLA-S is highest,DC breakdown strength of the three samples decreases when the temperature rises from 30℃to70℃,and PLA-S decreases slightly,only 16.7%.The conduction current of PLA-S increases with the increase of temperature,and the conductivity of PLA-W and PLA-A shows a rising-decreasing-rising trend.Combined with differential scanning calorimetry and polarized light microscopy,it is found that slow annealing is benefit to the crystallization of PLA,and the crystal cell size is large and the uniformity is good.The crystallinity of PLA-S is up to 50%,and the glass transition temperature is 23.7%higher than PLA-W.PLA-W and PLA-A samples are not completely crystalized,and unit cell growth or nucleation crystallization occur during the rise process of temperature.The increase in crystallinity leads to a rising-decreasing-rising trend in conduction current.

关 键 词：聚乳酸 环保材料 退火速率 直流击穿 电导电流 

分 类 号：TM215[一般工业技术—材料科学与工程]