Effects of Different Contents of Carbon Fiber on Properties of Polypropylene Composites

Polypropylene (PP) is a widely used plastic but is limited in some applications due to insufficient mechanical properties. Fiber's reinforcement can effectively improve the mechanical properties of PP.
In this paper, using PP as the matrix, chopped recycled carbon fiber (CF) as the reinforcing fiber, and adding 3%wt maleic anhydride grafted polypropylene (MA-g-PP) as the compatibilizer, the reinforcement effect of different contents of carbon fiber on polypropylene composites was studied.

Figure 1 is the cryogenically fractured cross-sectional SEM image of composites with different contents of CF. It can be seen from the figure that the CF is well embedded in the matrix, and the surface of the extracted CF is covered by a large amount of polymer. This shows that the adhesion between PP and CF is very strong, and the interface is not easily destroyed. It can be seen from the arrows at Figure 1(c) that the polymer is in the form of slender strips, which will help prevent the CF from debonding and prevent the interface from being damaged, thereby improving the mechanical properties of the material.

Figure 2 is the impact strength of the composite. It can be seen that the notched impact strength of the composites increases with increasing CF content. And when the addition amount is 20%, the notched impact strength is the highest, which is 5.2KJ/m2, which is 390% higher than that of the unreinforced matrix.

DOI No.：10.1007/s10965-021-02506-0