离子液体与水的混合体系中尼龙6的解聚反应

在150℃～230℃条件下,以氯化1-丁基-3-甲基咪唑离子液体与水组成的二元混合体系为介质进行尼龙6的解聚研究。固相残余物利用红外光谱和差示扫描量热仪进行分析。液相产物通过液相色谱-质谱联用仪和液相色谱进行定性与定量分析。建立了反应温度(A)、混合体系中离子液体的物质的量分数(B)以及反应时间(C)与ε-己内酰胺回收率(Y)之间的数学模型:Y(%)=43.76+6.69A+6.06B+3.60C+3.15AB+3.48AC-17.06A2-16.56B2-14.18C2,并利用响应曲面法(RSM)确定了解聚的优化工艺条件,即反应温度175℃、离子液体的物质的量分数14.2%及反应时间7.3h,此时ε-己内酰胺的回收率为44.4%、尼龙6的降解率为88.4%。

Depolymerization of Nylon 6 in Mixtures of the Ionic Liquid and Water

Depolymerization of nylon6 to ε-caprolactam was carried out in the ionic liquids and water binary mixtures from 150 to 230 ℃.The products of depolymerization were analyzed by means of infrared spectroscopy,differential scanning calorimeter,liquid chromategraphy-mass spectrometry and high performance liquid chromatography.Response surface methodology(RSM),based on three-variable-three-level Box-Behnken design(BBD),was used to determine the effects of the main parameters on nylon 6 depolymerization.A express of Y(%)=43.76+6.69A+6.06B+3.60C+3.15AB+3.48AC-17.06A2-16.56B2-14.18C2 was established to determine the yield of caprolactam at different reaction temperature(A),the ILs’ molar ratio(B),and reaction time(C).The optimal conditions for depolymerization was as follows: reaction temperature of 175 ℃,the molar ratio of IL 14.2%,and reaction time of 7.3 h.Under the condition,the yield of ε-caprolactam is 44.4% and the degradation rate of nylon 6 is 88.4%.