Biodegradable nanocomposite derived from PLA/PBAT blends with transition metal cation-doped porous clay heterostructures for flexible capacitor applications

Abstract

Polypropylene (PP) is the most widely used polymer film capacitor material, followed by polyester, due to its low dielectric loss and flexibility. The main disadvantage of polymer film capacitors is their low dielectric constant, which results in low capacitance. However, nonbiodegradable polymers have recently become a major electronic waste problem. This study aims to develop flexible nanocomposite films by combining a biodegradable poly(lactic acid) (PLA) with poly(butylene adipate-co-terephthalate) (PBAT). Epoxidized castor oil (ECO) was also used as a compatibilizer to improve compatibility between the PLA matrix and the PBAT dispersion phase. The compatible PLA/PBAT blend’s elongation at break increased by up to 33%. To enhance the dielectric constant, transition metal cations, such as manganese, cobalt, copper, and nickel cations, were doped in a porous clay heterostructure (PCH). The biodegradable nanocomposite film’s dielectric constant increased by almost four times (at 1 kHz) because of our efforts. Based on these findings, PLA/PBAT blends with transition metal cation-doped PCH can be employed as biodegradable polymer film capacitor alternatives.

KEYWORDS:

• Polymer blends
• compatibilization
• porous clay heterostructures
• dielectric properties

Acknowledgments

The authors gratefully acknowledge the financial supports by the 100th Anniversary Chulalongkorn University Fund for Doctoral Scholarship and the 90th Anniversary of Chulalongkorn University Fund (Ratchadaphiseksomphot Endowment Fund) as well as supported by Graduate School of Chulalongkorn University. The materials were supported by Thai Nippon Chemical Industry Co., Ltd. The instruments were supported by The Petroleum and Petrochemical College, Chulalongkorn University.