The Effect of Polylactic Acid-g-Maleic Anhydride on the Surface Compatibility of Polylactic Acid and Carbon Fiber

Polylactic acid is an emerging industrial material. Due to its high tensile strength and rigidity, it has received more and more attention, especially the compounding of polylactic acid with carbon materials can greatly improve the comprehensive performance of polylactic acid. But when polylactic acid and carbon fiber are combined, the gap between them hinders load transfer, so the compatibility of polylactic acid and carbon fiber becomes a key factor affecting the mechanical properties of composite materials. The compatibility between fibers and polymers can be improved by using surface modification, matrix modification, or compatibility with surface additives.

In this study, a reactive extrusion method was used to graft maleic anhydride onto polylactic acid to form polylactic acid grafted maleic anhydride, which was used as a compatibilizer between polylactic acid and carbon fiber. The effects of the different ratios of free radical initiator to maleic anhydride and the amount of polylactic acid grafting on the mechanical properties of polylactic acid/carbon fiber composites (Figure 1) and interface compatibility (Figure 2) are discussed. The test results show that the use of polylactic acid grafted maleic anhydride as a compatibilizer improves the interface compatibility of polylactic acid/carbon fiber composites. In addition, when the amount of polylactic acid grafted with maleic anhydride reaches 6wt%, it has a positive effect on its tensile properties, flexural strength and impact str

Figure 1. (a) Tensile strength, (b) tensile modulus, (c) elongation at break, and (d) stress–strain curves of PLA/CF composites.

Figure 2. SEM images (1000 × ) of the fractured PLA/CF composites that contain (a) 0, (b) 2, (c) 4, (d) 6, and (e) 8 wt% PLA-g-MA.