Preparation and Mechanical Properties of Polyurethane Elastomer with Two Soft Segments of HTPB/PTMG

In this paper, a series of polyurethane elastomers (PUE) were prepared employing casting method using toluene diisocyanate (TDI), hydroxy-terminated butadiene-acrylonitrile copolymer(HTBN) and polytetrahydrofuran glycol (PTMG) as the main raw materials, and using 2,4- and 2,6- dimethylthioaromatic diamine (DMTDA) as a chain extender. The effects of the content of NCO in PUE (NCO%), mass ratio of HTBN/PTMG, molecular weight of PTMG, dosage of chain extender and heat treatment on the mechanical properties of PUE were studied. The results showed that the lower molecular weight of PTMG and the higher heat treatment temperature were both favorable for increasing the mechanical properties of PUE. When the mass ratio of HTBN/PTMG was 35:65, NCO% was 6.0%, molar ratio of NCO/NH(2) was 1.20 and heat treatment time was 2h at 115 degrees C, the mechanical properties of PUE were best.