聚丁二酸丁二醇酯的合成及性能研究

Synthesis and properties of polybutylene succinate

选取钛酸四正丁酯(TBT)和二(乙酰丙酮)钛酸二异丙酯(DIPEAT)单独或复配作为催化剂,采用直接酯化-缩聚法,合成聚丁二酸丁二醇酯(PBS),研究了TBT,DIPEAT,TBT-DIPEAT(摩尔比1∶1)3种催化剂对缩聚反应速度及合成产物的物理性能、热稳定性和流变性能的影响。结果表明:3种催化剂的催化活性由高到低依次为TBT,TBT-DIPEAT,DIPEAT;DIPEAT催化合成的PBS的相对分子质量分布较窄,物理性能较好;相比TBT催化剂,DIPEAT催化合成的PBS的热稳定性较好,PBS失重5%时热分解温度提高约12℃;以TBT,DIPEAT或TBT-DIPEAT作为催化剂,得到的PBS的流动曲线相似,熔体的表观黏度随着剪切速率的增大而减小,随着温度升高而降低,都是切力变稀型非牛顿流体。

Poly （ butylenes succinate） （PBS） was synthesized by direct esterification-polycondensation method using tetrabutyl titanate （TBT） and titanium diisopropoxide bis （acetylacetonate） （DIPEAT） alone or complex as catalyst. The effects of TBT, DIPEAT and TBT-DIPEAT（ molar ratio 1 ： 1 ） on the polycondensation reaction rate and the physical properties, thermal stability and rheological properties of the obtained polymer were studied. The results showed that the activity of the three kinds of catalysts from high to low was TBT, TBT-DIPEAT, DIPEAT ; PBS prepared by using DIPEAT as the catalyst had narrower relative molecu- lar mass distribution and better physical properties; as compared with TBT, DIPEAT contributed better thermal stability to PBS and led to an increase of 12 ℃ or so in the thermal decomposition temperature at 5% weight loss of PBS; PBS obtained by using TBT, DIPEAT or TBT-DIPEAT as the catalyst had similar flow curves ; PBS melt was shear-thinning non-Newtonian fluid, whose apparent viscosity was decreased as the shear rate increased or the temperature rose.