Takami Hikita

Synthesis and Characterization of Ordered Polyurethanes from Tolylene 2,4-Diisocyanate and Ethylene Glycol

An ordered polyurethane with a head-to-head or tail-to-tail (H–H or T–T) content of 90% was prepared by polyaddition reaction of a nonsymmetric monomer, tolylene 2,4-diisocyanate (1) with a symmetric monomer, ethylene glycol (2). The polymerization was conducted in toluene in the presence of dibutyltin dilaurate (DBTL) at 0°C by slow addition of a half amount of 2 to 1, followed by removing toluene and then adding the rest of 2 in DMF at once at room temperature in the presence of DBTL. Furthermore, the authentic ordered and random polymers were prepared to verify the structure of the ordered polymer and it was found that the polymer had the expected structural regularity. The constitutional regularity of polymers influenced on their thermal properties.