【摘要】：聚酰亞胺薄膜因其優(yōu)良的電氣、機(jī)械及熱性能已在各種絕緣線纜中得到廣泛應(yīng)用。然而,環(huán)境應(yīng)力可能會(huì)造成聚酰亞胺降解,從而降低其絕緣性能。以聚酰亞胺普通薄膜和聚酰亞胺納米薄膜為測(cè)試對(duì)象,研究了單層膜、雙層膜及三層膜在不同溫度下的擊穿特性,分析了水分對(duì)聚酰亞胺薄膜擊穿場(chǎng)強(qiáng)的影響機(jī)制。結(jié)果表明:普通膜和納米膜的擊穿強(qiáng)度均隨試驗(yàn)溫度的升高而降低,尤其是當(dāng)試驗(yàn)溫度大于350℃時(shí),下降速率明顯增加,其主要原因是由于聚酰亞胺分子在高溫下移動(dòng)并發(fā)生熱降解。由于單層膜具有更好的散熱能力及結(jié)構(gòu)均勻性,因此單層膜具有比雙層膜和三層膜更高的擊穿場(chǎng)強(qiáng),納米膜較高的熱導(dǎo)率導(dǎo)致其具有更好的高溫穩(wěn)定性。潮濕環(huán)境中的水分子首先通過氫鍵作用與聚酰亞胺分子上的羧基(C=O)鍵結(jié)合,并進(jìn)一步與之發(fā)生水解反應(yīng),使聚酰亞胺薄膜的擊穿場(chǎng)強(qiáng)降低。
[Abstract]:Polyimide film has been widely used in all kinds of insulated cables because of its excellent electrical, mechanical and thermal properties. However, environmental stress may lead to degradation of polyimide, which reduces its insulation performance. The breakdown characteristics of polyimide thin films and polyimide nanocrystalline films at different temperatures were studied. The mechanism of the influence of water on the breakdown field strength of polyimide films was analyzed. The results show that the breakdown strength of the ordinary film and the nano-film decrease with the increase of the test temperature, especially when the test temperature is more than 350 鈩，

本文編號(hào)：2404278