Beta phase enhancement in PVDF-based copolymer by nanocomposites with modified clays

• Main Author: Yao, Xiaofeng.
• Other Authors: Lu Xuehong
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Materials::Defence materials
• Online Access: http://hdl.handle.net/10356/38801
• Institution: Nanyang Technological University

Poly (vinylidene fluoride) (PVDF) has drawn much attention due to the attractive properties such as piezo-, pyro-, and ferroelectricity, which are rarely exhibited in other polymers. The β phase has the largest spontaneous polarization (p) per unit cell of all polar phases and thus exhibits the highest piezo-, pyro and ferroelectric activities. This project aims to enhance β phase of PVDF based copolymer PVDF-HFP through the corporation of nanoclays. Three types of clays were used in this project namely clay1, clay2 and clay3. Clay1 is the pristine montmorillonite clay, clay2 is the pristine clay modified by organic surfactant and clay3 is POSS-modified clay of which the method of synthesis is explained in experiment procedure session. Clays were added into the polymer during the solution making step and thin films were made on glass slides by evaporating out all the solvents. The dry thin films were characterized by using polarizing microscope (POM), Wide Angle X-ray Diffraction (WAXD), Attenuated Fourier Transform Infrared Spectroscopy (AT-FTIR), Differential Scanning Calorimetry (DSC), and Contact Angle measuring equipment. The results showed that by incorporated with nanoclays, the β phase in the PVDF-HFP samples was enhanced. Among the three types of clays, clay3 shows the most significant effect on enhancing β phase, followed by clay2 and clay1 has the least effect.