The Strengthening and Toughening of Biodegradable Poly (Lactic Acid) Using the SiO2-PBA Core–Shell Nanoparticle

Abstract

The balance of strengthening and toughening of poly (lactic acid) (PLA) has been an intractable challenge of PLA nanocomposite development for many years. In this paper, core–shell nanoparticles consisting of a silica rigid core and poly (butyl acrylate) (PBA) flexible shell were incorporated to achieve the simultaneous enhancement of the strength and toughness of PLA. The effect of core–shell nanoparticles on the tensile, flexural and Charpy impact properties of PLA nanocomposite were experimentally investigated. Scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS) measurements were performed to investigate the toughening mechanisms of nanocomposites. The experimental results showed that the addition of core–shell nanoparticles can improve the stiffness and strength of PLA. Meanwhile, its elongation at break, tensile toughness and impact resistance were enhanced simultaneously. These observations can be attributed to the cavitation of the flexible shell in core–shell nanoparticles and the resultant shear yielding of the matrix. In addition, a three-dimensional finite element model was also proposed to illustrate the damage processes of core–shell nanoparticle-reinforced polymer composites. It was found that, compared with the experimental performance, the proposed micromechanical model is favorable to illustrate the mechanical behavior of nanocomposites.

A Review on Synthesis, Properties, and Applications of Polylactic Acid/Silica Composites

“…Several research teams have aimed to improve the mechanical properties of PLA with the addition of silica to the polymer matrix. For example, He et al [ 76 ] reported that the inclusion of silica nanoparticles is a good strategy to improve the mechanical properties of PLA. Indeed, the tensile strength (TS), Young’s modulus (YM), and impact strength of the PLA/silica composites made by the melt-mixing method were greatly increased with the addition of silica nanoparticles, which was linked to the good dispersibility of the particles in the polymer matrix, as well as PLA-silica interactions [ 77 ].…”

Numerical Simulation and Comparison of the Mechanical Behavior of Toughened Epoxy Resin by Different Nanoparticles

“…The numerical simulation of the microscale generally takes the representative volume element as the research object, and the reasonable selection is beneficial to reduce the calculation cost and present the failure mechanism more clearly. For the research object of this topic, there are two choices of representative volume element available: regular distribution representative volume element and random distribution representative volume element . In practice, even if the particle agglomeration phenomenon is not considered, the particle distribution in the matrix cannot be completely uniform but closer to the random distribution.…”

A Strategy to Develop Homo-polypropylene Composites with High Impact and High Rigidity

“…Up to now, core–shell rubber particles (CSRPs) have been widely used to toughen PP. − Using different core–shell structures to toughen PP has been studied extensively. For example, the core–shell structure of toughened PP can use PE as the core and EPR as the shell, , silicon dioxide-EPDM core–shell particles, and so on. − The addition of core–shell particles and the formation of a ternary blend system, according to the theoretical model proposed by Wu, can simultaneously improve the toughness and reduce the modulus loss in composite materials.…”