聚甲基丙烯酸甲酯的分子构型对淬火过程中聚偏氟乙烯(PVF_2)β相生成的影响

EFFECT OF TACTICITY OF PMMA ON β PHASE FORMATION OF PVF_2 DURING QUENCHING PROCESS

聚偏氟乙烯(PVF_2)是一种半结晶聚合物,它至少存在α、β、γ和δ四种晶相结构。其中β相由于其与PVF_2的压电性和热电性直接相关而引起人们的广泛关注。在以前的工作中,我们研究了超速淬火对PVP_2晶相结构的影响。本工作用傅里叶变换红外光谱(FTIR)技术研究了聚甲基丙烯酸甲酯(PMMA)分子构型对淬火过程中PVF_2β相生成温度的影响.

Fourier transform infrared spectroscopy (FTIR) has been used to study the effect of tacticity of PMMA on β-phase formation of poly (vinylidene fluoride) (PVFi) 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 interaction of hydrogen bonding between the molecules of PVF2 and PMMA, which stablizes the TTT conformation of PVF2 and forms the nucleation sites of the β-phase at higher temperature.