Scalable preparation of multiscale carbon nanotube/glass fiber reinforcements and their application in polymer composites

The introduction of carbon nanotubes (CNTs) into conventional fiber to construct a hierarchical structure in polymer composites has attracted great interest owing to their merits of performance improvement and multiple functionalities. However, there is a challenge for realizing the scalable preparation of the multi-scale CNT-glass fiber (CNTGF) reinforcements in practical application. In this work, we present a simple and continuous method of the mass production of multiscale CNT-glass fiber (CNT-GF) reinforcements. Scanning electron microscopy and thermo gravimetric analysis indicated ~1.0 wt% CNTs were highly dispersed on the whole fiber surface through a facile surfactant-assisted process. Such hybrid CNT-GF fillers were found to effectively enhance the stiffness, strength and impact resistance of polypropylene polymer. Increased storage modulus, glass transition temperature and crystallization temperature of the composites filled with the CNT-GF fillers were also observed in the differential scanning calorimetry and dynamic mechanical analysis compared with the composites containing the pristine GF fillers. Fracture surface analysis revealed enhanced interfacial quality between CNT-GF and matrix, which is likely responsible for improved performance of the hierarchical polymer composites.