Fully Aminated Rigid Rods Enhance and Toughen Epoxy‐Based Carbon Fiber Composites Through Molecular Combination and Novel Electrostatic Spraying Technology

ABSTRACT Carbon fiber reinforced polymers (CFRPs) have been extensively studied; they are primarily damaged at the resin matrix and resin–fiber interface. To solve these problems, in our previous studies, the strengthening and toughening effects of fully aminated p ‐polyaramid with rigid‐rod main chains and amino side groups on CFRPs have been verified. However, this method of molecular combination increased the resin viscosity and enhanced the processing difficulty. Now we introduce a novel electrostatic spraying technology, which can uniformly disperse fully aminated p ‐polyaramid onto the surface of carbon fibers. We also compared and studied the effects of both molecular combination and electrostatic spraying on the flexural properties of the CFRPs. The results showed that by using electrostatic spraying to enhance the interface strength, it is possible to maintain excellent performance while avoiding these processing problems: when only 0.75 wt% fully aminated p ‐polyaramid was added, the flexural strength, flexural modulus, total energy, and interlaminar shear strength of the CFRPs increased by 47%, 55%, 56%, and 54%, respectively. Electrostatic spraying offers simpler operation and more prominent strengthening/toughening effects than molecular combination. Electrostatic spraying of fully aminated p ‐polyaramid offers an inexpensive and highly efficient method to increase the flexural properties and interlaminar shear strength of CFRPs.