合成聚对苯二甲酸丙二醇酯负载型催化剂钛酸四丁酯/纳米二氧化硅的制备

以钛酸酯偶联剂(TMC-201)为改性剂,采用超声波分散方法对亲水性纳米二氧化硅(nano-SiO2)进行了表面改性。采用浸渍法将钛酯四丁酯(Ti(OC4H9)4)负载于表面改性的nano-SiO2上,制备了纳米级Ti(OC4H9)4/nano-SiO2负载型催化剂。考察了偶联剂用量、温度、时间对纳米SiO2表面改性的影响,研究了负载时间、负载温度和Ti(OC4H9)4用量对表面改性后纳米SiO2负载Ti(OC4H9)4的影响。结果表明,当TMC-201质量分数为35%、反应温度为90℃、反应时间为3.5 h时,纳米SiO2粒子表面接枝的偶联剂量最大;在室温下,负载48 h,Ti(OC4H9)4用量为表面改性纳米SiO2量的1/2时得到的Ti(OC4H9)4/nano-SiO2负载型催化剂负载Ti(OC4H9)4量最大;运用ICP-AES、FESEM等测试技术对修饰后的纳米SiO2及Ti(OC4H9)4/nano-SiO2负载型催化剂进行了表征;将Ti(OC4H9)4/nano-SiO2负载型催化剂用于聚对苯二甲酸丙二醇酯(PTT)聚酯合成的结果表明,与均相Ti(OC4H9)4催化剂相比,Ti(OC4H9)4/nano-SiO2负载型催化剂催化合成PTT聚酯过程中酯化时间177 min,与均相催化剂催化酯化时间相近,在缩聚2 h后得到PTT的特性粘度高达1.05,证明该负载型催化剂具有高的催化活性,既可催化酯化反应又可催化缩聚反应。

Preparation of n-Butyl Titantate/Nano Silicon Oxide Catalyst for Synthesis of Poly (trimethylene terephthalate)

Nano-SiO2 was modified with titanate coupling agent（TMC-201） under ultrasonic dispersion. n-Butyl titanate[Ti(OC4H9)4]/nano-SiO2 catalysts were successfully prepared by loading Ti(OC4H9)4 on the surface of modified nano-SiO2 particles via impregnation method. The impacts of titanate coupling agent， temperature and time on the surface modification of hydrophilic nano-SiO2 were studied. The impacts of Ti(OC4H9)4 content, supported temperature and supported time loading on modified nano-SiO2 particles were investigated. The results indicated that the titanate coupling agent was fully grafted on nano-SiO2 when TMC-201 content was 35% of nano-SiO2, modification temperature was 90 ℃, modification time was 3.5 h. The Ti(OC4H9)4/nano-SiO2 catalysts were the best when the using of Ti(OC4H9)4 was 50% of modified nano-SiO2, supported time was 48 h at room temperature. The modified nano-SiO2 and Ti(OC4H9)4/nano-SiO2 catalysts were characterized by ICP-AES and FESEM. Compared with the Ti(OC4H9)4 catalysts, the Ti(OC4H9)4/nano-SiO2 catalysts exhibited excellent catalytic activity. The esterification time in the synthesis of the poly(trimethylene terephthalate)(PTT) with Ti(OC4H9)4/nano-SiO2 catalysts was 177 min. The viscosity was improved to 1.05 after 2 h polycondensation.