Mechanical, thermal, and viscoelastic properties of polypropylene/glass hybrid composites reinforced with multiwalled carbon nanotubes

This experimental study is conducted to investigate the mechanical, thermal, and viscoelastic properties of isotactic polypropylene reinforced with short glass fibers and multiwalled carbon nanotubes. The study of morphological properties shows that multiwalled carbon nanotubes were completely mixed with neat polypropylene at low contents of multiwalled carbon nanotube, whereas some part of agglomeration was observed for 1.5 wt.%. Optimum tensile and flexural properties were achieved by adding 1 wt.% multiwalled carbon nanotube and 20 wt.% short glass fibers to polypropylene matrix. Dynamic mechanical thermal analysis results demonstrated improvements in the storage and loss modulus by increasing multiwalled carbon nanotube content up to an optimum value due to higher degrees of stress transfer from the matrix to the filler. Also, a reduction in loss factor was observed because of the interfacial bonding improvement between the constituents. Differential scanning calorimetry results revealed increasing of the crystallization peak temperature and the degree of crystallinity in the presence of multiwalled carbon nanotubes.