STRUCTURE AND MECHANICAL-PROPERTIES OF NYLON-6.12 PREPARED BY TEMPERATURE SLOPE CRYSTALLIZATION .2. ROLLING DEFORMATION AND MICROHARDNESS OF THE ORIENTED NEGATIVE SPHERULITE

Oriented negative spherulites of nylon 6.12 were crystallized by the t emperature slope method. Rolling deformation of the negative texture w as performed in three directions. The deformation mechanism of the neg ative spherulites was investigated by x-ray diffraction and microhardn ess measurements. Slip deformation between crystalline lamellae (inter lamellar slip) was observed in the first stage of deformation. The res ults are compared with the rolling deformation of other polymer textur es such as the positive spherulites of nylon 6.12 and beta-phase isota ctic polypropylene. In the rolling deformation of nylon 6.12, hydrogen -bonded (010) planes play an important role. For large deformations (l ambda > 1.5), preferential slip between (010) planes appears, resultin g in a lamellar inclination of 60 degrees and a decrease of the lamell ar thickness. Microhardness measurements after rolling deformation of the oriented negative texture show good agreement with the structural analysis. The rapid decrease in the microhardness with increasing defo rmation can be explained by the lamellar thickness decrease brought ab out by the preferential slip between the (010) planes.