异戊二烯热聚合过程及阻聚剂阻聚效果的研究

Thermal Polymerization Process of Isoprene and the Effects of Inhibitors

以微型高压反应釜为反应器,采用气相色谱内标法和重量法相结合的方法,考察了反应时间、反应温度、气相氧含量、阻聚剂种类及用量对异戊二烯(IP)热聚合的影响。实验结果表明,IP聚合产物包括二聚物和高聚物两种。反应时间对聚合产物中二聚物的比例无明显影响;升高反应温度,聚合产物中二聚物的比例显著增加;增大气相氧的含量,高聚物的生成量增加;添加适量阻聚可完全抑制高聚物的生成,对二聚物的生成无影响。3种阻聚剂阻聚效果由高到低的顺序为:2,2,6,6-四甲基哌啶氧化物(TEMPO)>二乙基羟胺>对叔丁基邻苯二酚。通过实验数据拟合得到在无氧且添加800×10-6(w,基于IP质量)的TEMPO条件下,IP自二聚反应速率常数(k1)的表达式为:k1=3.89×106exp(-95.6×103/RT)。

The thermal polymerization of isoprene（IP） was carried out in a high pressure microreactor. The effects of reaction time,reaction temperature,oxygen content in gas phase and inhibitors on the polymerization were investigated by means of gas chromatographic analysis and gravimetric method. The results showed that the products consisted of dimer and high polymers mainly. Reaction time had no influence on the dimer content in the products. High reaction temperature was significantly beneficial to increasing the dimer content. The polymerization was enhanced by increasing the oxygen content in gas phase. Proper inhibitors could completely restrain the formation of the high polymers without influence on the IP dimerization. The order of the inhibition effect under the same reaction conditions was 2,2,6,6-tetramethyl-1-piperidyloxy（TEMPO）diethyl hydroxylaminep-tertbutylcatechol. The rate constant equation（k1） of the IP dimerization was obtained through experiments without oxygen in gas phase and with TEMPO dosage of 800×10-6（w,based on the IP mass）：k1=3.89×106exp（-95.6×103/RT）.