Rc. Cieslinski et al., REAL-TIME CRYO-DEFORMATION OF POLYPROPYLENE AND IMPACT-MODIFIED POLYPROPYLENE IN THE TRANSMISSION ELECTRON-MICROSCOPE, Polymer, 36(9), 1995, pp. 1827-1833
Dynamic plane-stress failure has been observed directly in the transmi
ssion electron microscope as a function of temperature using a commerc
ially available cooling/straining holder in conjunction with a copper
deformation cartridge. The low-temperature cooling stage permits studi
es of the ductile-brittle transition when the transition is between +2
3 and -170 degrees C. A change in deformation mode was observed on the
submicrometre level for polypropylene and impact-modified polypropyle
ne. At room temperature, polypropylene and impact-modified polypropyle
ne deform by shear yielding. Below the ductile-brittle transition the
polymer chain mobility is curtailed and crazing dominates. The stage a
llows observation of the deformation at varying temperature, and event
s occurring during the deformation can be recorded in real time using
a CCD camera.