Study on biodegradable nanocomposites of poly(3-hydroxylbutyrate-co-3-hydroxylvalerate) grafting functionalized carbon nanotubes

The ability to render carbon nanotubes (CNTs) with biocompatibility opens up an entire new and exciting research direction in the field of biological and biomedical engineering including sensing, imaging and scaffolding for cell growth. This work is concerned with chemical modification of the CNTs surface with biological components. We have prepared a biocompatible composite through the covalent link between carboxylic groups of functionalized multi-walled carbon nanotubes (MWCNTs) and hydroxyl groups of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). FT-IR results demonstrated chemical modification was achieved through the esterification reaction. TEM showed that the MWCNTs were coated with a uniform PHBV layer, and the MWCNTs existed as a hard backbone. Thermal analysis indicated that the crystallization behavior of composite was markedly hindered due to the presence of carbon nanotubes. With the incorporation of MWCNTs and PHBV, a significant increase in the thermal stability of PHBV was caused. The curves of TGA showed that temperature determined at 5% weight loss (T-5%), initial decomposition temperature (T-0), maximum decomposition temperature(T-max) and complete decomposition temperature (T-f) increased by the amplitude of 18 degrees C, 19.3 degrees C, 20.5 degrees C and 36.1 degrees C, respectively, compared to those of original PHBV.