氧化铝固载杂多酸催化合成聚四氢呋喃

SYNTHESIS OF POLYTETRAHYDROFURAN OVER ALUMINA SUPPORTED HETEROPOLY ACIDS

以氧化铝固载杂多酸(HPA/Al2O3)为催化剂、环氧氯丙烷(ECH)为促进剂催化四氢呋喃(THF)开环聚合,合成了含有ECH结构单元的端羟基聚四氢呋喃(PTHF)。考察了催化剂制备条件、促进剂用量和反应温度对产物收率和数均相对分子质量的影响。结果表明,催化剂的酸强度(H0)在+0.8^+3.3范围内的酸量会影响反应收率,酸量越多,收率越高,得到的聚合产物有合适的数均相对分子质量(700~3000)和较窄的相对分子质量分布(Mw/Mn<2.0)。最佳聚合条件为反应时间4 h,杂多酸负载量35%(质量分数),n(ECH)/n(THF)=0.12,反应温度50℃。

The alumina supported heteropoly-aeid catalysts were prepared and used in the polymerization of THF in the presence of epichlorohydrin （ECH） to obtained the poly-tetrahydrofuran（PTHF） containing ECH moieties. The effects of the preparation conditions, the dosage of ECH and reaction temperature on the yield and number-average molecular mass of PTHF were investigated as well. The reaction results indicated that the acid amount corresponding to -4-0.8 〈 H0≤＋3.3 on catalysts related to the yield of PTHF with the number-average molecular mass in the range of 7003000 with narrow distribution Mw/Mn〈 2.0, that is, the more the acid amount of ＋0.8〈H0≤＋3.3, the higher the yield of PTHF. The optimal reaction conditions were n （ECH）/n （THF） = 0. 12, the reaction temperature of 50℃, the reaction time of 4 h and the catalyst with a 35% （mass fraction） loading of heteropoly-acids.