响应面法优化Fe_3O_4/NiO催化聚对苯二甲酸乙二醇酯醇解

Optimization of Fe_3O_4/NiO Catalyzed Alcoholysis of Polyethylene Terephthalate by Response Surface Methodology

以Fe_3O_4为磁性基质,采用液相共沉淀法制备磁性固体碱催化剂Fe_3O_4/Ni O,并用于聚对苯二甲酸乙二醇酯(PET)的醇解反应。以催化醇解反应得到的对苯二甲酸二乙二醇酯(BHET)回收率为指标,通过响应面法优化得到催化剂合成的最佳条件,即前驱体n(Fe_3O_4)∶n[Ni(AC)_2]=1∶3.94,反应时间1.67 h,催化剂煅烧时间2.01 h,煅烧温度600℃。以最优条件制备的催化剂在乙二醇介质,反应温度195℃,降解反应时间4 h,催化剂用量为PET质量的2.0%的条件下进行醇解反应,BHET回收率达到81.47%。采用XRD、BET和SEM对催化剂进行表征,结果表明:催化剂具有片状结构,比表面积较大,降解产物是BHET。

Fe3O4/Ni O catalyst was prepared by a liquid phase co-precipitation method and used for alcoholysis of polyethylene terephthalate（PET）.The preparation conditions of Fe3O4/Ni O were optimized by response surface methodology（RSM）using the recovery rate of bis（2-hydroxyethyl）terephthalate（BHET）as the response values.The optimum preparation conditions obtained by RSM analysis were as follows：molar ratio of Fe3O4to Ni（AC）21∶3.94,reaction time 1.67 h,calcination time 2.01 h,calcination temperature 600℃.The optimized conditions for alcoholysis of PET by Fe3O4/Ni O catalyst were obtained.When the reaction temperature was 195℃,the reaction time was4 h,the catalyst dosage was 2.0%,the recovery rate of BHET reached 81.47%.The as-prepared catalysts were characterized by means of XRD,BET and SEM.The results showed that the flake-like Fe3O4/Ni O catalyst had a large surface area.Moreover,FTIR and^1HNMR results confirmed that the degradation product was BHET.