Study On The Synthesis And Properties Of Non-Isocyanate Thermoplastic Poly (Ester Amide Urethane) S And Polyureas

In this paper, a series of non-isocyanate thermoplastic poly(esteramide urethane)s (NI-TPEAUs) and polyureas (NI-TPUA) were prepared from a green starting material, i.e. ethylene carbonate (EC), a substitute of diisocyanates, through melt transurethane poly condensation. These non-isocyanate routes avoided the use of toxic diisocyanates, the major synthesis precursor of which is the extremely toxic phosgene. Green synthesis route is established. The major researches and the main achievements in this paper are described as follows:1.. NI-TPEAUs were prepared by a feasible route introducing L-alanine oligomers to improve their biodegradable and biocompatible properties. This route includes following steps:(a) prepare L-alanine oligomers(o-PAs) terminated with HOOC-groups, (b) synthesize poly(ester amide) prepolymers terminated with HO-groups (PrePEAs or HO-PrePEA-OHs) from o-PAs and excessive 1,4-butanediol, (c) prepare poly(ester amide urethane)s containing L-alanine oligomers via melt polycondensation of the HO-PrePEA-OH with homopolymers of 1,6-bis(hydroxyethyloxy carbonyl amino)hexane (PBHCHs). The obtained NI-TPEAUs were characterized by gel permeation chromatography (GPC), FT-IR and’HNMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile testing. The s-PEAUs exhibited an Mn up to 18600, an Mw up to 42900, Tg between 16.03 ℃ and 27.48 ℃, initial decomposition temperature at over 259.0 ℃ and tensile strength up to 21.9 MPa with elongation at break of between 74.24%. Some urea linkages were formed during transurethane polycondensation.2、 Researchers HDA synthetized thermoplastic [n,m]-polyureas from the reaction of diurethanediols with diamines. However, in this synthesis route, diurethanediols must be prepared previously, and purification is also needed. In this paper, a simple one-pot non-isocyanate route for synthesizing [n]-polyureas is presented. This route overcomes the problems above mentioned. A series of thermoplastic polyureas (NI-TPUA) was prepared. The obtained NI-TPUA were characterized by gel permeation chromatography, FTIR,’H-NMR, wide angle X-ray scattering, differential scanning calorimetry, thermogravimetric analysis (TGA), Atomic Force Microscope (AFM) and tensile test. NI-TPUA-Ds, which were constructed mainly with D230, exhibited an Mn up to 11200, an Mw up to 19800, Tg between 15.0 ℃ and 41.9 ℃, initial decomposition temperature at over 289.9℃ and the tensile strength up to 32.34 MPa with elongation at break from 9.30% to 1330.12%. NI-TPUA-Bs, which were constructed mainly with B220, exhibited an Mn up to 16728, an Mw up to 65311, Tg between -27.87 ℃ and -17.05 ℃, two Tm between 76 ℃ and 103.5 ℃, initial decomposition temperature at over 312.6℃, and a tensile strength up to 19.75 with elongation at break from 13.02% to 332.97%. NI-TPUAs with good tensile strength were prepared through a green and simple one-pot non-isocyanate route.