Fourier transform infrared spectroscopy (FTIR) has been used to study the effect of tacticity of PMMA on β-phase formation of poly (vinylidene fluoride) (PVF2) during quenching process. For pure PVF2

quenching at lower temperature results in formation of β-phase crystallites. The critical quenching temperature for 3-phase formation is about 30℃. Adding a given amount of PMMA (30%)

especially syndiotactic PMMA (s-PMMA)

into PVF2 results in increase of the critical quenching temperature upto 70℃. This is due to the interac-tion of hydrogen bonding between the molecules of PVF2 and PMMA

which stablizes the TTT conformation of PVF2 and forms the nuchleation sites of the β-phase at higher temperature.