Laser‐Heated Drawing of Syndiotactic Polystyrene Fiber

The laser drawing phenomena of syndiotactic polystyrene fiber was analyzed through a numerical simulation of fiber temperature profiles, and the structure and properties of laser‐drawn fibers were compared with the results of contact heater‐drawn fibers. The low oriented and amorphous as‐spun fibers could be drawn steadily up to 5.0 times by laser‐drawing with increasing laser power with the increase of draw ratio, while it could not be drawn over 4.4 times by heater‐drawing. The fiber drawn over 4.4 times by laser‐drawing showed saturating phenomena in birefringence, initial modulus, and elongation at break, while fiber strength solely continues to increase with draw ratio. As the results, higher maximum strength 400 MPa of laser‐drawn fiber than 374 MPa of heater‐drawn fiber, as well as higher toughness were obtained. In addition, laser‐drawn fiber showed larger d‐spacing along the lateral directions, larger crystallite size along the (002) direction, and higher melting temperature.