Effect of liquid butadiene rubber on mechanical properties of polyamide 11/polyamide 12 blends

Polyamide 11 (PA 11)/polyamide 12 (PA 12) blends with and without liquid polybutadiene (LB) containing isocyanate end groups (LBD) were prepared in the Brabender plastograph. The rubber was added in order to increase the impact strength of the polyamides. Tensile strength and elongation at the upper yield point and hardness were also measured. Thermal properties were determined by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Fourier transform infrared (FTIR) spectroscopy was used to determine functional groups of polyamides and to reveal possible reactions between the polyamides and LBD. Intrinsic viscosity, measured by an Ubbelohde viscometer, was used to calculate molar mass. The LB has been found as a useful modifier of impact strength.