Functionally graded polymer composites: Simulation of fiber distribution

Abstract

Centrifugation is a method to create functionally graded materials (FGM) with a thermosetting matrix. In this study the movement of short carbon fibers in an epoxy resin during the centrifugation process was modeled to determine the fiber distribution in the final product. For this purpose a form factor K was introduced to modify a set of equations that was previously shown to be valid for the motion of spheres. It was shown that the results of the simulation were in good agreement with the experimental data, when an empirical K factor of four was chosen.

Effects of various fillers on the sliding wear of polymer composites

“…In the meantime it was also possible to create a software tool for predicting the filler distribution after centrifugation [67].…”

Autocatalytic phase separation and graded co-continuous morphology generated by photocuring

“…7 Ultracentrifuge has been also used to produce a concentration gradient of metallic compounds in polymer matrices such as epoxy resins. 8,9 The methods of producing these FGMs have so far relied heavily on polymerization of a guest monomer or on the spatial distribution of a guest polymer in the bulk state of a host polymer by using certain techniques such as sorption or diffusion etc. In general, the concentration gradient generated in this way may be influenced not only by the sizes of the guest monomer and polymer via diffusion, but is also limited by the thermodynamic interactions between monomer of the guest and the host polymer segments.…”

Development of functionally graded vapor-grown carbon-fiber/polymer materials

“…Also, sudden property jumps, for example, in hard coatings, are undesirable, since these can cause stress singularities at interfaces, associated with local coating failure as a result of spalling‐off effects. For these purposes, the creation of a filler distribution gradient is an effective way of preparing wear resistant materials .…”

“…Many achievements have been made in recent years. SiC particles and carbon fibers have been used as reinforcing agents in polymer matrices; based on these experiments, simulations of polymer‐based FGMs have been developed . However, in order to develop advanced FGMs with excellent properties and multifunctions, the introduction of grading agents is necessary.…”