Enhanced thermal and electrical properties of poly (D,L-lactide)/multi-walled carbon nanotubes composites by in-situ polymerization
(1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;2. College of Medicine, Jiaxing University, Jiaxing 314001, China;3. College of Material and Textile Engineering, Jiaxing University, Jiaxing 314001, China)
Abstract: Biodegradable poly (D,L-lactide) (PLA)/carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs) composites were achieved via in-situ polymerization. These as-prepared composite materials were characterized with FT-IR, XRD, TG, DSC, SEM, and high insulation resistance meter. The results demonstrate that the multi-walled carbon nanotube was carboxyl functionalized, which improved the collection between c-MWCNTs and PLA, and further realized the graft copolymerization of c-MWCNTs and PLA. There is a higher glass transition temperature and a lower pyrolysis temperature of PLA/c-MWCNTs composites than pure PLA. The c-MWCNTs gave a better dispersion than unmodified MWCNTs in the PLA matrix, and an even coating of PLA on the surface of c-MWCNTs was obtained, which increased the interfacial interaction. High insulation resistance analysis showed that the addition of c-MWCNTs increased the electric conductivity, and c-MWCNTs performed against the large dielectric coefficient and electrostatic state of PLA. These results demonstrated that c-MWCNTs modified PLA composites were beneficial for potential application in the development of heat-resisting and conductivity plastic engineering.
Key words: in-situ polymerization; multi-walled carbon nanotubes; polylactide; thermal properties; electrical conductivity