Isothermal Melt Crystallization Kinetics Study of Biodegradable Poly(3-hydroxybutyrate)/Multiwalled Carbon Nanotubes Nanocomposites

Abstract

Poly(3-hydroxybutyrate) (PHB) is a truly biodegradable and highly biocompatible polymer; [1][2][3][4][5][6] however, wider application range of PHB has been limited because of its stiffness and brittleness problems. Moreover, its melting temperature is so close to the thermal decomposition temperature that PHB becomes thermally unstable during processing. Therefore, many attempts have been made to improve its mechanical and thermal properties, among which polymer blending is an easy and convenient way of achieving desirable combination of properties. Ha et al. and Di Lorenzo et al. have recently reviewed miscibility, properties and biodegradability of polymer blends containing PHB. 7,8Addition of nano-particles such as carbon nanotubes (CNTs) to form nanocomposites has provided another means to improve materials performances.9,10 CNTs possess unique mechanical, electrical and thermal properties that make it ideal candidates to substitute conventional nano-fillers in the fabrication of polymer nanocomposites. [11][12][13][14][15][16] It is noted that the strong interfacial adhesion between polymer chains and nanotubes is critically important to effectively maximize load transfer from the matrix to CNTs. Recently, PHB/single walled carbon nanotubes (SWCNTs) nanocomposites have been prepared by solution casting method using chloroform as cosolvent. 17 The experimental results showed that the crystalline size substantially decreased for the PHB/SWCNTs nanocomposite with a 1% weight fraction of SWCNTs as compared to that of neat PHB; moreover, the polymer nanocomposite films showed an increase in hardness and Young's modulus with increasing SWCNTs contents. 17To the best of our knowledge, biodegradable PHB/multiwalled carbon nanotubes (MWNTs) nanocomposites have not been reported so far in the literature. We have recently prepared PHB/MWNTs nanocomposites at different MWNTs loadings by solution casting method and studied the effects of the presence of MWNTs and their loadings on the subsequent multiple melting behavior of PHB in the nanocomposites crystallized non-isothermally from the melt. 18 In this note, we further studied the isothermal melt crystallization kinetics of neat PHB and the PHB/MWNTs nanocomposites for a better understanding of the influence of the presence of MWNTs and the loadings on the crystallization behavior of PHB in the PHB/MWNTs nanocomposites.

A study on the melting and crystallization of polyoxymethylene‐copolymer/hydroxyapatite nanocomposites

“…The depression of T m 0 for POM in the POM/HAp nanocomposites indicates that there is some miscibility between POM and HAp because of interactions between ether oxygens of POM and functional –OH groups of HAp. Similar effect was observed in poly(3‐hydroxybutyrate)/MWCNT nanocomposites by Xu and Qiu . Moreover, a decrease of the value of T m 0 with the addition of HAp suggests that the crystalline phase in POM/HAp composites is less perfect than that of pure POM.…”

“…Similar effect was observed in poly(3-hydroxybutyrate)/MWCNT nanocomposites by Xu and Qiu. [44] Moreover, a decrease of the value of T m 0 with the addition of HAp suggests that the crystalline phase in POM/HAp composites is less perfect than that of pure POM. This phenomenon is probably due to the presence of more intensive heterogeneous nucleation, which reduces the perfection of POM crystallites in the nanocomposites.…”

Application of Poly(hydroxyalkanoate) In Food Packaging: Improvements by Nanotechnology

“…Additionally, some nanocomposites for food packaging (especially for beverage) applications are in the marketplace or being developed with the extraordinary benefits to improve food packaging 5 . PHAs nanocomposites filled with layered silicates such as MMT, layered double hydroxides (LDHs), multi-walled carbon nanotubes (MWCNTs), and cellulose nanowhiskers (CNWs) are reported 106 . The property improvement is in direct correlation with increased nanofiller dispersion.…”

Polyhydroxyalkanoates (PHAs) for food packaging

“…Studies have been dedicated to examining nanocomposites based on PHAs filled with layered silicates such as montmorillonite (MMT), layered double hydroxides (LDHs), cellulose nanowhiskers (CNWs), and multi-walled carbon nanotubes (MWCNTs) (Xu and Qiu, 2009). The rationale is that introduction of nanofillers into a polymer matrix can significantly modify morphology, crystallisation behaviour, thermal stability, mechanical and barrier properties, and biodegradation rate, all of which are relevant from the food packaging perspective.…”