Preparation and properties of bio-based poly(urea-amide)s
A series of bio-based poly(urea-amide)s(PUAs)with high strength and high toughness were synthesized through a one-pot method using urea,1,10-decanediamine,and diacids as raw materials without any catalyst or any sol-vent.Di(aminodecyl)urea was first synthesized via urea ammonolysis with 1,10-decanediamine and then polymerized with different diacids such as 1,10-decanedioic acid(DA10),1,12-dodecanedioic acid,and dimer acid(DmA).The chemical structures of the as-synthesized PUAs were confirmed by 1H-NMR and FTIR spectroscopy,and their Mn's are about 12~13 kg/mol.The PUAs are processible with tensile strength of 25~45 MPa and elongation at break of 400%~700%.The strain at break value of PUA-DA10 is approximately twice as much as PA1010,whereas these two materi-als exhibit similar tensile strength.The strain at break of PUA-DmA is higher than that of PA-DmA,but they show simi-lar tensile strength.The introduction of urea groups into the backbones of polyamides can improve their performance.This simple synthetic method is quite suitable for enhancing the performance of bio-based polyamide as well as for their diverse design and applications.