Abstract
From the previous studies performed on the Polyacrylonitrile(PAN)/HNO₃(soIvent)/H₂0(nonsolvent) spinning system based on the critical coagulation bath composition(CCBC),it has been found that the bath composition(CBC) has markedly affected the structure and properties of the resulting fibers, and furthermore that fibers obtained from the higher CBC's than the CCBC had better structure and properties compared to the case of the lower CBC's as a result nf retarded phase transitions at higher CBC's Hence, in this paper, the effects of the CBC around the CCBC on structure and mechanical properties of drawn PAN fibers formed have been investigated by varying the draw ratio. Namely, such physical properties as density, dyeing absorption, birefringence, dynamic viscoelas tic behavior, wide angle X-ray diffraction, degree of orientation, and specific stress have been measured on drawn fibers spun at two different coagulation conditions, i.e. CBC = 35 and 41.8% corresponding to before and after the CCBC, respectively.
