| 초록 |
Poly(vinylidene difluoride) (PVDF) is a semi-crystalline polymer, whose molecular structure has the repeated monomer unit (-CH2-CF2-)n. The most common polymorph of PVDF is an α-phase, which has a monoclinic unit cell with TGTĞ(T=Trans, G=Gauche+, Ğ = Gauche-) conformation. β-phase polymorph is less stable than α-phase, while showing highly polarized dipole moments and piezoelectric property with its all trans(TTTT) conformation. There can be other conformational polymorphs in PVDF, γ, δ and ε polymorphs, but they are minor to α and β. Non-isothermal crystallization analysis about homo PVDF and PVDF-MWCNTs nanocomposites provides some important information about the crystalline structure development of these materials. From a non-isothermal crystallization exotherm, we developed the Avrami equation in Seo's method to get the Avramic exponent, n. And the polarized optical microscopy showed the recrystallization behavior at consistent cooling rate. |
