Synthesis and properties of monodisperse hydroxy-terminated oligomers of 1,4-butanediol and 2,4-toluene diisocyanate

The synthesis of monodisperse hard segments containg 2,4-TDI and 1,4-butanediol by a simple technique is described. High purity material is obtained in good yield. The structures of these hard segments are confirmed by proton n.m.r., 13Cn.m.r., and i.r. Glass transition temperatures and melting temperatures are reported. The T g′s of the hard segments are inversely proportional to the reciprocal of their molecular weights. The T m′s show an odd-even effect relative to the number of 2,4-TDI units in the hard segment.