EFFECT OF HALLOYSITE NANOTUBES ON MATRIX MICROCRACKING IN CARBON FIBER/EPOXY COMPOSITES

CHURRUCA MARÍA JOSÉ; J. MORÁN; E. RODRIGUEZ

MECHANICS OF COMPOSITE MATERIALS

SPRINGER

Lugar: Berlin; Año: 2022 vol. 58 p. 293 - 304

0191-5665

Matrix microcracking is considered the main responsible for gas permeation in linerless pressure vessels and storage tanks. The addition of halloysite nanotubes (HNTs) at different concentrations was studied in order to enhance microcrack resistance. An increase of 50% on the cracking onset stress was found for a 5% addition of HNTs into the epoxy matrix. Moreover, an increase of 60% was observed for a similar level of microcrack density compared with neat epoxy. Reactive diluent was used as an alternative to keep viscosity suitable for filament winding process and to offset the rise in viscosity due to HNTs incorporation. Despite the fact that matrix fracture toughness increased even up to 10% of HNTs, no benefit in microcrack resistance was found for more than 5% of HNTs. As a result, it is expected that the microcracking phenomenon will be affected not only by matrix fracture toughness but also by residual thermal stress