五价有机铋的合成及其在聚氨酯中的应用

Synthesis and application of pentavalent organic bismuth for polyurethane

合成了7种无毒的新型有机铋催化剂,采用核磁共振仪、质谱仪(MS)和红外光谱仪(FTIR)等对其进行表征,确认了其化学组成,并将其应用于聚氨酯涂膜材料制备,研究催化剂结构和添加量等对涂膜的固化时间、抗腐蚀性能和拉伸性能等的影响。结果表明,五价有机铋催化剂性能明显好于三价铋,0.3%(质量分数,下同)的铋金属催化剂即可将聚氨酯涂膜的固化时间缩短至其四分之一,耐溶剂性能提高30%,拉伸强度增加33%,断裂伸长率降低35%;铋分子中芳基的平面性对其活性影响很大,含有氧桥二苯结构配体的催化剂由于平面性好,显示出了较好的催化性能。

Seven novel types of nontoxic organic bismuth catalysts were synthesized,and their chemical compositions were confirmed by nuclear magnetic resonance spectroscopy,mass spectroscopy,and infrared spectroscopy.Then,these catalysts were used to prepare polyurethane coating materials,and the effects of catalyst structure and dosage on the curing time,corrosion resistance and tensile properties of the polyurethane coating films were investigated.The re-sults indicated that the pentavalent organic bismuth catalyst exhibited better catalytic performance than the bismuth triva-lent one.The bismuth metal catalyst with a total mass fraction of 0.3 wt%shortened the curing time of polyurethane coating films one quarter,significantly improving their solvent resistance by 30%and tensile strength by 33%,but re-ducing their elongation at break by 35%.The bismuth catalyst promoted not only the polymerization reaction but also the chain crosslinking and aggregation to some extent,thus improving the performance of the films.The planarity of the aryl group in the bismuth molecules had a great influence on its activity,and the catalyst containing the oxygen-bridged di-phenyl ligand showed good catalytic performance due to its good planarity.