Blends of TPS with modified MWCNT: Characterization and Application.

Abstract

In the present work, thermoplastic starch-based composites with functionalized multi-walled carbon nanotubes as a filler were prepared, characterized and their potential use as conductive materials were evaluated. The multi-walled carbon nanotubes (MWCNT) were synthesized by the CVD method using CaCO3 8% Fe 2% Co as catalyst, and the MWCNT functionalization was performed by refluxing them with HNO3 concentrated. Thermoplastic starch (TPS) composites were synthesized using glycerol as a plasticizer and adding functionalized MWCNT (f-MWCNT) in the starch matrix in four different concentrations: 0.5% (0.5TPS), 1% (1TPS), 2% (2TPS), and 4% (4TPS). The presence of carboxylic functionalization in MWCNT was confirmed by FTIR, Raman spectroscopy, and XPS spectroscopies analysis, while the TGA allows to quantify the presence of oxygen groups in f-MWCNT. FTIR and Raman spectroscopy analysis of the TPS/f-MWCNT composites confirmed the presence of the filler in the starch matrix, and UV-vis analysis studied the chemical interaction of f-MWCNT in the starch matrix. The composites showed a decrease in the degree of crystallinity as well as in the maximum decomposition temperature as the f-MWCNT were added. The electrical conductivity test reveals an increase in conductivity, except for 1TPS composite, with respect to composite without f-MWCNT. Moreover, the composite degradation tests shows a slightly higher 1TPS composite degradation rate than the other composites, including composite without f-MWCNT.