Effect of particle morphology on the mechanical and thermo-mechanical behavior of polymer composites

Abstract

Fiber reinforced polymer composites have been used in many applications, such as in automobile, aerospace and naval industries, due basically to their high strength-to-weight and modulus-to-weight, among other properties. Even though particles are usually not able to lead to the level of reinforcement of fibers, particle reinforced polymer composites have been proposed for many new applications due to their low cost, easy fabrication and isotropic properties. In this work, polymer composites were prepared by incorporating glass particles of different morphologies on poly(aryl sulfones) matrices. Particles with aspect ratios equal to 1, 2.5 and 10 were used. The prepared composites were characterized using electron microscopy and thermal analysis. Mechanical properties of the composites were evaluated using a four-point bending test. The thermo-mechanical behavior of the obtained composites was also investigated. The results showed that the morphology of the particles alter significantly the mechanical properties of composites. Particles with larger values of aspect ratio led to large elastic modulus but low levels of strain at failure. This result was explained by modeling the thermo-mechanical behavior of the composites using a viscoelastic model. Parameters of the model, obtained from a Cole-Cole type of plot, demonstrated that interactions at the polymer-reinforcing agent interface were higher for composites with large aspect ratio particles. Higher levels of interactions at interfaces can lead to higher degrees of stress transfer and, consequently, to composites with large elastic modulus, as experimentally observed

Synthesis and in vitro bioactivity assessment of injectable bioglass−organic pastes for bone tissue repair

“…2b and 2d). Earlier it was demonstrated that higher aspect ratio of reinforcing agents affected more pronouncedly the viscoelastic behaviour of the systems, by imposing constraints to the mobility of the polymer chains [33]. The relatively isometric glass particles used in the present study are expected do not disturb much the flow behaviour.…”

Obtenção de compósitos de resíduos de ardósia e polipropileno

“…Fibras são notoriamente capazes de reforçar matrizes poliméricas, enquanto partículas podem não contribuir substancialmente como reforço [5,6] . No entanto, partículas são mais abundantes e menos onerosas do que fibras, o que tem motivado a busca por sistemas de reforço de plásticos à base de material particulado [7,8] .…”

Relaxation behavior and activation energy of relaxation for polyimide and polyimide–graphene nanocomposite

“…Relaxation occurs whenever polymer chains rearrange themselves to adopt either a lower energy conformation or to fill free volume. The shape of the Cole–Cole plot is affected by factors such as differences in the structure of segmental units within a polymer chain, heterogeneities due to inherent processing characteristic features including (1) molecular weight distribution, (2) free volume distribution, (3) filler concentration, (4) degree of crystallinity and thermomechanical history . Nonsymmetrical semi‐circle curve of the Cole–Cole plot for the polymer and polymer composites is indicative of the system's heterogeneity…”