Synthesis of Low-monol Polyether Polyols by Using Highly Active Catalysts and Their Applications to High-performance Polyurethanes

摘要

Polymerizations of propylene oxide have been carried out by using double metal cyanide (DMC) catalysts based on Zn_3[Co(CN)_6]_2. By controlling the type and the amount of complexing agent during preparation of catalyst the catalytic activity, initiation time, and the unsaturation level in polyether polyols could be tuned. By using polytetramethylene ether glycol (PTMEG) as a co-complexing agent together with tertiarybutyl alcohol, conventional complexing agent, the catalytic activity was sharply improved, the initiation time became short, and the unsaturation level was greatly lowered. The selection of the type of PTMEG was also important to maximize the effect of co-complexing agent. Various catalysts prepared by changing the complexing agent were characterized by x-ray photoelectron spectroscopy, infrared spectroscopy, and x-ray powder diffraction. ~(13)C NMR analysis showed that the polyols have a random distribution of the configurational sequences and head-to-tail regiosequence, even if the amount of [rr] triad of polyol produced by DMC catalyst was larger than that of polyol by conventional KOH catalyst. The distortionless enhancement by polarization transfer analysis showed that there exist regioirregular sequences as well. The stress-strain curves of methylene diisocyanate/ 1,4-butanediol cured polyurethanes showed that the monol content contained in polyol showed a dramatic effect on the mechanical properties of resulting polyurethane.