Effects of stretching ratio and temperature on phase transition of melt-spun poly(vinylidene fluoride) fibers

The effects of stretching ratio and stretching temperature on phase transition of melt-spun poly vinylidene fluoride) fibers were investigated and analyzed by using scanning electron microscopy, wide angle Xray diffraction, differential scanning calorimetry and Fourier transfer infrared spectroscopy. The beta phase exists in, the as-spun fiber. The beta phase content increases as the stretching ratio increases. When the stretching temperature is lower than 100 degrees C, enhancing temperature is good for the transition of phase alpha to beta. By contrast, when the stretching temperature is higher than 100 degrees C, enhancing temperature is unfavourable for the transition of phase a to beta. Increasing the draw temperature increases the alpha-phase content..