Rigid particle toughening of aliphatic polyketone

The thermal properties of the matrix remained unchanged upon addition of CaCO3. With increasing particle content the modulus increased and the yield strength decreased. This decrease in yield strength is due to the debonding of the particles and was similar as with rubber particles. With increasing particle content the notched impact resistance increased strongly. The notched impact energy at room temperature was increased from 10 to 80 kJ/m2 and the brittle-to-ductile transition temperature was lowered to 80 °C. At calcium carbonate contents higher that 16 vol% no further impact improvement was observed. The calcium carbonate particles seemed to debond quite well despite the expected thermal contraction of the matrix polymer. The temperature development in the deformation zone was strong, as strong as with rubber particles. The toughening mechanism with these rigid particles is discussed.