Influence of elastomer distribution on the cryogenic microcracking of carbon fiber/epoxy composites

Abstract

Carbon fiber/epoxy laminates containing three different types of rubber modifiers, separately and in combination, were developed for testing in a cryogenic environment. Preformed rubber particles, core shell rubber, and solid carboxyl-functionalized rubber were chosen as additives to a model prepreg matrix to control the placement of the rubber within the resulting laminates. Cryogenic microcracking and mode I and II fracture toughness and interlaminar shear strength experiments were performed. Scanning electron microscopy was used to observe fracture surfaces of the rubber-modified laminates. Fracture toughness properties were improved while the ILSS decreased because of the presence of these rubber modifiers. It was observed that the presence of these modifiers significantly reduced the microcrack density of the laminates exposed to cryogenic cycling, and in the case of one, even eliminated microcracking entirely.

A Review of the Polymer for Cryogenic Application: Methods, Mechanisms and Perspectives

“…Preformed rubber particles, core-shell rubber (DP5031, Zeon Chemicals Inc., Shanghai, China), and solid carboxyl functional rubber (Nipol1472, Zeon Chemicals Inc.) were used to modify the resin by Nobelen [99]. Their study focused on the influence of the toughener types on the microcracking response to cryogenic cycling of the fiber-reinforced laminates.…”

Life extension of self-healing polymers with rapidly growing fatigue cracks

“…One method of improving the fatigue performance of brittle polymeric materials is to increase the inherent fracture toughness of the polymer. Methods of increasing the fracture toughness of the polymer include incorporating a rubbery second phase (Bascom et al 1981;Kinloch et al 1983;Becu et al 1997;Rey et al 1999;Hayes & Seferis 2001;Nobelen et al 2003), incorporating solid particles (Azimi et al 1995;Sautereau et al 1995;McMurray & Amagi 1999) or the addition of microcapsules (Azimi et al 1996;Brown et al 2006) to the polymer matrix. Additional methods of reducing the fatigue crack propagation rate include crack-tip shielding mechanisms such as crack closure (Elber 1970(Elber , 1971Ur-Rehman & Thomason 1993;Sharp et al 1997;Shin et al 1998;Song et al 1998), which introduces a wedge in the crack plane and reduces the effective stress intensity at the crack tip, and hydrodynamic pressure crack-tip shielding (experiments and theory developed mainly for metals), which reduces fatigue crack growth due to the viscous flow between the crack faces (Galvin & Naylor 1965;Endo et al 1972;Polk et al 1975;Plumbridge 1977;Plumbridge et al 1985;Tzou et al 1985a,b;Davis & Ellison 1989;Yi et al 1999;Brown et al 2005a).…”

Drawdown prepreg coating method using epoxy terminated butadiene nitrile rubber to improve fracture toughness of glass epoxy composites

“…This is a simple, and rapid alternative method as discussed earlier to incorporate rubber in carbon fibre-reinforced epoxy prepreg system as discussed in our previous work, 5 but our study was limited to mode-I and mode-II fracture toughness. This method is more efficient than the use of costly and time-consuming dispersion techniques [20][21][22][23][24][25] making it potentially scalable for large-scale manufacturing. This investigation aims to study the experimental assessment of fracture behaviour and ETBN dispersion and its prepreg coating process through scanning electron microscope (SEM), dynamic mechanical analysis (DMA) and Fourier transform infrared spectroscopy (FT-IR) spectra.…”