The purpose of this work was to show in a conclusive way the c!b phase transformation induced by uniaxial stretching in poly(vinylidene fluoride). Poly(vinylidene fluoride) films were melted and crystallized at 163 C for 36 h. Under these conditions, a mixture of a and c phases was formed, with a predominance of the latter. These films were uniaxially stretched at 130 C at a draw ratio of 4. Fourier transform infrared and differential scanning calorimetry analyses showed a c!b phase transition in the solid state, whereas orientation of the a phase without any transition was observed. Optical microscopy analysis permitted the observation of the transformation of spherulitic structures into oriented lamellae during stretching.

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