Synthesis and characterization of novel poly(urethane-urea) elastomers based on 1,3-propanediol bis(4-aminobenzoate) as chain extender

Abstract This paper presents the study of new polymer materials based on polycaprolactone diol and hexamethylene diisocyanate, containing urethane and urea groups which are bound both through flexible ether chains as well as through rigid benzene rings belonging to the chain extender structure (1,3-propanediol bis(4-aminobenzoate)). The structure of the chain extender determines the ability of the polymer matrix to perform physical interconnections. A range of cross-linkers with different flexible to rigid structures cross-linkers (propane-1,2,3-triol, castor oil, 1,2,3-benzentriol, 4,5-bis(hydroxymethyl)-2-methylpyridin-3-ol) were used in order to obtain chemical bonds between the polymer chains. The structure and properties of the prepared poly(urethane-urea) were characterized by Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetry (TG). FTIR measurements showed a decrease in mobility within the hard segment with the increase in chain extender content. DMA analysis revealed a secondary relaxation towards the rubbery transition. Poly (urethane-urea) elastomers obtained on the basis of 1,3-propanediol bis (4-aminobenzoate) showed good heat resistance at up to 300 °C and excellent mechanical properties with breaking strength of 65 MPa.