(409h) Biodegradable Poly(3-hydroxybutyrate) Nanocomposites: The Role of Organo-Modified Nanoclays On the Thermomechanical Characteristics Via a Design of Experiments Study

Poly(3-hydroxybutyrate) (PHB) is a biodegradable, biocompatible polyester in the family of poly(hydroxyalkanoates) (PHAs),  produced by microorganisms from renewable resources. Its mechanical properties are similar to those of polypropylene (PP), an oil-derived engineering polymer, and that’s why, PHB is considered a very promising green alternative to PP. However, PHB is prone to thermal degradation and this is one serious obstacle for its widespread use.

In the present work, we report the preparation and the thermomechanical characterization of a series of hybrid materials based on poly(3-hydroxybutyrate)  and organo-modified montmorillonite clay according to an experimental design. The hybrid materials were prepared by the melt mixing method in a micro-exruder/-compounder under constant nitrogen flow to prevent the thermal decomposition of PHB. Various organo-modified clays with (1) different numbers of carbon atoms in the alkylammonium cation chain and (2) different concentrations of the alkylammonium salt equivalent to 0.5×, 1.5× and 2.5× the cation exchange capacity (CEC) of the clay were used.  Following the experimental design, various loadings (1%, 3% and 5%) of the organo-modified clay were also employed. The structure of the as-prepared materials was examined with the aid of X-Ray diffraction (XRD) technique and the thermo-mechanical properties were tested by using Differential Scanning Calorimetry (DSC), Thermogravimetry (TGA) and Dynamic Mechanical Thermal Analysis (DMTA). The test results are analyzed according to the Design of Experiments (DoE) statistical methodology and the conclusions of this analysis will be presented.