空气氛围中SMC热解气态产物释放规律研究

Study on the Release of Gaseous Products from SMC Pyrolysis in Air Atmosphere

为更好的实现气体组分分析法在中高压开关柜局部放电检测这一领域的应用,文章对SMC热解气态产物释放规律进行研究。得出以下结论:随着热解温度的升高SMC失重率呈先增大后趋于稳定再增大的趋势,热解温度为200℃~500℃时,失重率呈增大的趋势由1.29%增加至32.38%。500℃~700℃,失重率趋于稳定由32.38%变化至32.05%。700℃~800℃后样品失重率由32.05%增加至52.07%;SMC在200℃~800℃热解温度下,生成的气态产物主要包含有机和无机小分子物质、杂环类物质、酮、脂、醛、卤代烃、苯系物、烷烃和烯烃、链状及环状硅氧化合物;在200℃~800℃ SMC热解过程整体上分为三个阶段,分别为200℃~500℃的快速解离阶段、500℃~700℃的相互转化阶段以及700℃~800℃的稳定解离阶段,快速解离阶段键能较低的化学键发生断裂重组生成小分子气态物质和高碳中间体物质,相互转化阶段生成物之间发生复杂的氧化还原反应而发生相互转化,稳定解离阶段高碳中间体物质继续分解为稳定态小分子物质。

In order to realize the application of gas component analysis method in partial discharge detec-tion of medium and high voltage switchgear, the gas product release law of SMC pyrolysis was studied in this paper. The following conclusions are drawn: With the increase of pyrolysis temperature, the SMC weight loss rate firstly increases, then tends to be stable and then increases. When the pyrolysis temperature is between 200˚C and 500˚C, the SMC weight loss rate increases from 1.29% to 32.38%. At 500˚C~700˚C, the weight loss rate tends to be stable from 32.38% to 32.05%. The weight loss rate increased from 32.05% to 52.07% at 700˚C to 800˚C. At the pyrolysis temperature of 200˚C to 800˚C, the gaseous products of SMC mainly contain organic and inorganic small molecules, heterocyclic substances, ketones, lipids, aldehydes, halogenated hydrocarbons, benzene series, alkanes and alkenes, chain and cyclic silico compounds. The pyrolysis process of SMC at 200˚C~800˚C can be divided into three stages as a whole, namely the rapid dissociation stage at 200˚C~500˚C, the mutual transformation stage at 500˚C~700˚C and the stable dissociation stage at 700˚C~800˚C. In the rapid dissociation stage, the chemical bonds with lower bond energy break and recombine to form small gaseous substances and high carbon intermediates. In the mutual transformation stage, complex redox reactions occur between the products and mutual transformation occurs. In the stable dissociation stage, the high carbon intermediates continue to decompose into stable small molecular substances.