Studies On Synthesis And Properties Of Non-Isocyanate Thermoplastic Polyurethanes

The main purpose of this paper is to study how to synthesis polyurethane via transurethane polycondensation non-isocyanate, and to improve the performance. Some diamide- and diester-containing monomers were synthesized at first, and then were polymerized with 1,6-bis(hydroxyethyloxy carbonyl amino) hexane (BHBC) via melt transurethane polycondensation in the presence or absence of polyether glycols. A series of thermoplastic polyurethanes were synthesized. The main contribution is showed as below:1. Melt transurethane polycondensation of BHBC with 3 EG or 4EG and HEHA, which was prepared from the condensation of diethyl adipate with ethanolamine, was carried out at 170? under a reduced pressure of 399 Pa. A series of aliphatic thermoplastic poly(amide-ether-urethane)s (TPAEUs) containing amide and ether linkages were synthesized. The TPAEUs were characterized by gel permeation chromatography, FT-IR,1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray scattering, and tensile test. And The TPAEUs had a Tm at up to 144.9 ?, and tensile strength up to 18 MPa with elongation at break up to 79%.The TPAEUs exhibit high Tm and good mechanical properties.2. N,N-bis(2-hydroxyethyl)isophthalamide (HYIP) was first synthesized from the reaction of dimethyl isophthalate with aminoethyl alcohol. Melt transurethane polycondensation of BHBC and HYIP with o-PEG was carried out at 170? under a reduced pressure of 399 Pa, and a series of partial aromatic NI-TPAEUs with amide and ether linkages were synthesized. Their tensile strength reached 32 MPa with elongation at break from 26% to 210%. NI-TPAEUs with high Tm (up to 143.20?) and excellent mechanical properties were prepared.3. Bis(4-hydroxybutyl) terephthalate (BHBT) was first synthesized from the condensation of dimethyl terephthalate with excessive 1,4-butanediol. Then melt transurethane polycondensation of BHBC and BHBT was carried out at 170? under a reduced pressure of 399 Pa. A series of NI-TPUs containing dibutylene terephthalate units were prepared. Their tensile strength reached 38 MPa with elongation at break up to 475%. Tm ranges from 123.8 ? to 141.1?. These NI-TPAEUs owned excellent mechanical property and thermal stability.4. Transurethane polycondensation of BHCH with BHBT and different polytetrahydrofuran (PTMG) was carried out at 170? under a reduced pressure of 3 mmHg. A series of non-isocyanate thermoplastic polyurethane elastomers (NI-TPUs) containing dibutylene terephthalate units were prepared. Their tensile strength reached 38 MPa with elongation at break from 720% to 1201%. Tm ranges from 99.94? to 109.51?. These NI-TPUs owned excellent mechanical and thermal properties.