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采用间歇式高压反应装置研究聚碳酸酯(PC)在亚临界水中的解聚.在温度260～340℃、压力4.8～14.8 MPa、反应时间5～60 min的反应条件下,考察了反应温度及反应时间对PC解聚率及主产物双酚A(BPA)和苯酚(PhOH)回收率的影响.产物分别采用傅里叶红外光谱(FTIR)、扫描电子显微镜(SEM)、气质联谱(GC-MS)和气相色谱(GC)进行分析.实验结果表明,亚临界水能有效地降解PC,反应温度和反应时间是影响PC降解的主要因素.在反应温度300℃,反应压力8.7 MPa,反应时间45 min条件下,PC完全解聚,目标产物BPA收率36.88%,苯酚收率31.16%.在实验基础上,提出PC水解反应机理.通过实验数据关联,得出解聚反应级数为准一级,解聚反应活化能为125.7 kJ.mol-1.
The depolymerization of polycarbonate (PC) in subcritical water was studied by means of a batch high pressure reactor under the reaction conditions of temperature 260 ~ 340 ℃, pressure 4.8 ~ 14.8 MPa and reaction time 5 ~ 60 min.The effects of reaction temperature and Reaction time on the depolymerization rate of PC and the recovery rate of BPA and PhOH.The products were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), gas chromatography-tandem mass spectrometry -MS) and gas chromatography (GC) .Experimental results show that the subcritical water can effectively degrade PC, the reaction temperature and the reaction time are the main factors that affect the degradation of PC. At the reaction temperature of 300 ℃, the reaction pressure of 8.7 MPa, the reaction The reaction time was 45 min, the PC was completely depolymerized, the yield of BPA was 36.88% and the yield of phenol was 31.16% .According to the experimental data, the mechanism of PC hydrolysis was proposed.According to the experimental data, At the first stage, the deactivation activation energy is 125.7 kJ · mol-1.