PREPARATION OF RIGID-ROD POLY(P-PHENYLENE BENZOBISTHIAZOLE) FILMS OF SINGLE-CRYSTALLINE TEXTURE

Thin films of rigid-rod poly(p-phenylene benzobisthiazole) having sing le crystalline texture were prepared. An above critical concentration polymer solution of 6wt% in methane sulfonic acid was sheared to orien t the chains (c-axis) along the shear axis in the solution state. The sheared solution was then solidified into thin films via coagulation i n the water. Self-assembling phenomenon, previously found in rigid-rod PBZT polymer molecules during the coagulation process, was utilized a s the driving mechanism for the alignment of crystallographic a and b- axes in the process. WAXS and FTi.r. spectroscopy with the polarized r adiation confirmed the presence of single crystal-like orientation in the film specimen with the crystallographic c-axis preferentially orie nted parallel to the shear direction, b-axis to the transverse directi on, and a-axis normal to the film surface. (C) 1997 Elsevier Science L td.