Blends of biorenewable polyamide-11 and polyamide-6,10

Biorenewable polyamide-11 (PA11) is blended with partially biorenewable polyamide-6,10 (PA610) to produce thermoplastics of varying renewable carbon content. DSC thermograms show melting point depression for the PA610 crystals with increasing PA11 composition thus indicating that the two polyamides are fully miscible in the melt; the blends exhibit crystallization induced phase separation. Wide angle x-ray scattering measurements show that crystals of pure PA11 and pure PA610 form in all blends upon cooling. Small angle X-ray scattering shows an increase in lamellar long spacing with increasing PA11 content. Mechanical and thermal properties of these blends are characterized by differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical thermal analysis, tensile testing, and impact testing. Mechanical properties of the blends show intermediate values compared to the homopolymers but with a positive deviation from a simple law of mixtures; significant improvements in the properties of PA11 with the incorporation of 25wt% PA610 are observed. The present study provides extensive data on the physicochemical properties of a promising biorenewable blend system which exhibits the novel feature of thermodynamic miscibility.