Dynamic mechanical behavior and thermal properties of microcrystalline cellulose (MCC)-filled nylon 6 composites

The dynamic mechanical behavior and thermal properties of nylon 6 composites containing from 2.5 wt.% to 30 wt.% MCC were investigated using differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The DSC results indicated that there was no consistent or significant change in the glass transition (Tg), melting temperature (Tm) and crystallization temperature (Tc) of the composites with the addition of MCC. The DSC results also indicated that the crystallinity (Xc) decreased with high MCC loading level (more than 20 wt.%) because of the inability of polymers chains to be fully incorporated into growing crystallinity lamella. With increasing MCC content, storage modulus from DMTA improved because of the reinforcing effect of the MCC. The tan δ peak values from DMTA were not significantly changed as the MCC content increased. DMTA also indicates that the magnitude of the tan δ maximum peak of MCC filled composites was significantly decreased around the glass transition temperature. Thermogravimetric analysis also indicated that the MCC did not show significant initial degradation under 300 °C, which implies thermal stability so that MCC-filled composites could be used for high temperature circumstances, like in “under the hood” applications in the automobile industry.

DMTA storage modulus and tan(δ) of nylon 6 and MCC-filled nylon 6 composites from −50 to 150 °C as a function of temp.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Microcrystalline cellulose (MCC) used as reinforcing filler for engineering thermoplastic composites. ► MCC-filled composites could be used for high temperature circumstances, like in “under the hoo” applications in the automobile industry. ► Additional processing advantages arising from the use of MCC reinforcements instead of inorganic reinforcements are price, renewable nature, abundance, and low density, relatively reactive surface and high specific modulus. ► MCC-filled composites showed comparable or better mechanical properties compared to control samples without compatibilizers.