MICROMECHANICAL TESTING OF TOUGHNESS IN NYLON 6 PDMS BLOCK-COPOLYMERSAND BLENDS/

Small specimens of nylon 6/PDMS compositions were screened for relativ e levels of toughness using a micromechanical testing device. Measurem ents were made of the total crack length emanating from pre-cut notche s in a specially designed specimen. At room temperature, cracks propag ated readily in nylon 6 homopolymer and somewhat more slowly in a comp osition containing 4 wt% PDMS; at 10 and 28 wt% PDMS the cracks were b lunted in a diffuse whitened zone and did not propagate through the sp ecimens. At -40 degrees C, the 10 wt% blend appeared to be as tough as the 4 wt% blend at room temperature.