Improving the Tensile and Tear Properties of Thermoplastic Starch/Dolomite Biocomposite Film through Sonication Process

Abstract

In this work, dolomite filler was introduced into thermoplastic starch (TPS) matrix to form TPS-dolomite (TPS-DOL) biocomposites. TPS-DOL biocomposites were prepared at different dolomite loadings (1 wt%, 2 wt%, 3 wt%, 4 wt% and 5 wt%) and by using two different forms of dolomite (pristine (DOL(P) and sonicated dolomite (DOL(U)) via the solvent casting technique. The effects of dolomite loading and sonication process on the mechanical properties of the TPS-DOL biocomposites were analyzed using tensile and tear tests. The chemistry aspect of the TPS-DOL biocomposites was analyzed using Fourier transform infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD) analysis. According to the mechanical data, biocomposites with a high loading of dolomite (4 and 5 wt%) possess greater tensile and tear properties as compared to the biocomposites with a low loading of dolomite (1 and 2 wt%). Furthermore, it is also proved that the TPS-DOL(U) biocomposites have better mechanical properties when compared to the TPS-DOL(P) biocomposites. Reduction in the dolomite particle size upon the sonication process assisted in its dispersion and distribution throughout the TPS matrix. Thus, this led to the improvement of the tensile and tear properties of the biocomposite. Based on the findings, it is proven that the sonication process is a simple yet beneficial technique in the production of the TPS-dolomite biocomposites with improved tensile and tear properties for use as packaging film.

The Mechanical and Thermal Properties of Poly(ethylene-co-vinyl acetate) (PECoVA) Composites with Pristine Dolomite and Organophilic Microcrystalline Dolomite (OMCD)

“…The reduction in particle size of dolomite has increased its surface area. As a result, signals from XRD that went through the crystalline lattices of dolomite particles became stronger [9]. Figure 5 shows the results of XRD pattern of the virgin PECoVA, PECoVA/DOL3, and PECoVA/OMCD3 composite in the range of 10 • to 90 • .…”

“…In the production of the polymer/dolomite composite, the good mixing between the polymer matrix and dolomite filler will determine the properties of the produced composites [ 8 , 9 ]. Therefore, reduction of particle size of dolomite is crucial to increase its surface area and facilitate its dispersion and distribution inside the polymer and copolymer matrices.…”

“…The potential of dolomite to improve the properties of polymer matrices have been proven in various studies [ 9 , 11 , 12 , 13 , 14 ]. Ankabi et al employed a grafting method to improve the mechanical properties of the polypropylene/dolomite composite.…”

“…Thus, the polymer composite with the treated dolomite may exhibit greater thermal stability than one the composite with the untreated dolomite. Lastly, in the most recent publication, dolomite filler has been proven to significantly improve the tensile and tear strength of the thermoplastic starch film, showing that this mineral filler is also capable to enhance the mechanical properties of the natural or bio-based polymers [ 9 ].…”

Biopolymers from Natural Resources

“…Osman et al [ 20 ] studied thermoplastic starch (TPS)-based biocomposites using dolomite (DOL) as a filler in its pristine form (DOL(P)), as well as dolomites, after a simple and scalable sonication process (DOL(U)). TPS-DOL biocomposites intended for packaging applications were prepared at different loadings (i.e., 1, 2, 3, 4 and 5 wt.%).…”