Study On The Synthesis And Properties Of Urea Monomers And Polyesteramides By NON-ISO-cyanate Method

Polyester-amides have the properties both of polyester and polyamide,so it is biodegradable. it also has good mechanical properties.Polyester-amides are widely used in biomedicine. We must improve thethermal and mechanical properties of biodegradable material to meet theneed of new technology. The paper has discuss the synthesis of ureamonomer. We choose N-hydroxyethyl-N’-octanediamine-urea to make acondensation polymerzation, and then make chain extension with it.Finally we get high molecular and fine mechanical polyester-amideswhich has urea key.The main works as follows:Firstly, We prepared bis(2-hydroxyethyl)urea with urea or dimethyl-carbonate and ethanolamine. Then synthesis pre(polyester-urea)(PrePEU)with bis(2-hydroxyethyl)urea and adipic acid.Secondly, short chains of polyurea were prepared with urea and1,8-octanediamine or1,6-hexanediamine at the ratio2:1and2:3. But theshort chains are not solute very well and their melting points are very high.We can not continue make reaction with them; We tried dimethylcarbonate reaction with1,6-hexanediamine at the ratio2:1, ethanolaminewas added into with equal ratio of dimethyl carbonate;2-oxazolidinonewas prepared with urea and ethanolamine in DMF. Reactive functionalgroup terminated urea monomer was prepared by2-oxazolidinone andhexanediamine/octanediamine. The urea monomer was characterized by FT-IR and1HNMR. The influence of solvent on the experiment was alsostudied.Thirdly, a series of low molecular weight pre(polyester-amide) withurea key(PrePEAU) were synthesized through melt condensationpolymerization from1,4-butanediol, sebacic acid andN-hydroxyethyl-N’-octanediamine-urea. The chain extension of them wereperformed using PBOX and ABC as combined chain-extenders. Highmolecular weight ExtPEAUs with intrinsic viscosity of0.38-0.72dL/gwere obtained. The structure of ExtPEAUs were characterized by FT-IRand1HNMR spectra. The result showed that H-bounds of the urea key wasformed. The investigate of WAXS showed that the crystallizationbehaviour of ExtPEAUs is exactly similar with PA610. The ExtPEAUshad tensile strength up to23.96MPa. The ExtPEAUs can be use asthermoplastic plastic.