A non-isocyanate route to synthesize high molecular weight aliphatic thermoplastic polyurethanes through transurethane polymerization from a diurethanediol was provided.A homopolymer of 1

6-bis(hydroxyethyloxy carbonyl amino)hexane (BHCH)

i.e.PBHCH

was synthesized via melt polycondensation of BHCH.The PBHCH had Mn of 29200

Mw of 39700

tensile strength of 28.41 MPa and elongation at break of 3.91%.Meanwhile

a nylon-6 oligomer having H2N and HO terminal groups (H2N-PA-OH) was prepared via ring-opening polymerization from caprolactam with ethanolamine

and was transformed into HO terminated nylon-6 oligomer (HO-PA-OH) through reaction with excessive caprolactone.Co-polycondensation of BHCH with HO-PA-OH was carried out at 170 ℃ under normal pressure for 4 h and at 180 ℃ under reduced pressure of 399 Pa for 6.5 h.Several aliphatic thermoplastic poly(amide-urethane)s having short nylon-6 segments (s-PAUs) were prepared.They were characterized by viscometry

gel permeation chromatography

FTIR

1H-NMR

differential scanning calorimetry

thermogravimetric analysis

wide angle X-ray scattering and tensile test.The s-PAUs had Mn above 26000

Mw above 33900

Tm between 123.85 and 170.89 ℃

and initial decomposition temperature over 267.86 ℃.Their tensile strength reached 28.53 MPa with elongation at break up to 299.0%.These s-PAUs were constituted with short nylon-6 segments and PBHCH sequences or merely dicarbamate units.The s-PAUs were crystallizable thermoplastic polyurethanes.Introducing about 10 mol% short nylon-6 segments having polymerization degree of 2.55 increased the crystallinity of the PBHCH sequences

and improved the toughness of the s-PAUs obviously.