Thermal Analysis of Polyamide 6 Composites Filled by Natural Fiber Blend

Abstract

aThis study describes changes in the viscoelastic and thermal properties of composites made with various percentages (up to 20 wt.%) of a natural fiber blend (a mixture of flax, kenaf, and hemp fibers) and polyamide 6 (PA 6). According to the differential scanning calorimetry (DSC) analyses, the incorporation of natural fibers produced minor changes in the glass transition (Tg), melting (Tm), and crystallization temperature (Tc) of the PA 6 composites. Because of the reinforcing effect of natural fibers, the storage modulus (E') from dynamic mechanical thermal analysis (DMTA) increased as the natural fiber content increased. The E' values at room temperature and Tg were 3960 MPa and 1800 MPa, respectively, with the incorporation 20 wt.% fiber, which were 68% and 193% higher than the E' value of neat PA 6. As the natural fiber content increased, the thermal stability of the composites decreased, and thermogravimetric analysis (TGA) showed that the onset temperature of rapid thermal degradation decreased from around 440 (neat PA 6) to 420 °C (20 wt.% natural fiber blend). The addition of 20 wt.% single type fibers showed comparable DSC and TG results to the incorporation of 20 wt.% natural fiber blends.

Structure and properties of compatibilized recycled polypropylene/recycled polyamide 12 blends with cellulose fibers addition

“…While at intermediate shear rates, the network breaks down and cellulose aligns in the direction of shear [20]. The rheological properties of the composites in this research are in good agreement with the behavior reported by other authors for cellulose-based composites [31][32][33][34][35][36].…”

“…Natural fibers are very promising candidates for achieving this target due to their several advantages, such as renewability, biodegradability, low density, low cost, non‐abrasive characteristics during processing, as well as high mechanical performance and strength compared to synthetic fibers . Furthermore, it has been more popular to add natural fibers into polyamide composites in order to promote better compatibility for higher thermal and mechanical performance compared with those of polyolefin‐based composites with natural fibers . Among natural fibers, cellulose is the most abundant natural resource and has gained substantial interest during the last decade.…”

Cellulose NANOFIBER‐polyethylene nanocomposites modified by polyvinyl alcohol

“…Generally, a reduction of tensile strength was expected after the mixing cellulose fillers into hydrophobic matrices caused by incompatibility between hydrophilic cellulose and hydrophobic matrices, but the CNF‐reinforced composites with PVA as a carrier system displayed enhanced tensile properties compared with the neat PE in this study . Due to better compatibility as well as better stress‐ transfer properties, tensile strength of the composites was greater (increasing by 25% to 17.4 MPa with the addition of 5% CNF) …”

Preparation and characterization of wood‐fiber‐reinforced polyamide 6–polypropylene blend composites

“…There is a problem with mixing the low thermal stability of natural fibers and the high melting temperature ( T m ) of PA6 (220 °C). Researchers previously reported that when PA6 and natural fibers were directly blended to prepare composites via injection molding, hot pressing, and extrusion at temperatures of 230 and 250 °C, severe thermal degradation occurred. To improve the thermal stabilization of natural fibers, some modification methods, such as NaOH solution treatment, plasma treatment, and heat treatment, were imposed .…”