PLA/SiO₂ composites: Influence of the filler modifications on the morphology, crystallization behavior, and mechanical properties

Abstract

Films of an architecturally modified poly(lactic acid) (PLA REx ) with three different types of fumed silica nanofillers (SiO 2 ) were processed through reactive extrusion-calendering in a pilot plant. The effects of the SiO 2 type on both the dispersion and the crystallization behavior under dynamic and isothermal conditions are investigated using transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The mechanical properties are assessed by tensile testing. TEM micrographs showed that the improved chemical affinity of both surface-treated SiO 2 toward PLA REx end groups did not improve particle dispersion. DSC results revealed that untreated SiO 2 nucleated PLA REx more efficiently than both surface-modified silicas. The activation energy for the isothermal crystallization process, as determined by an Arrhenius method, suggests that addition of untreated SiO 2 enhances the crystallization rate of PLA REx . However, it seems that the tensile behavior remained unchanged whether silicas were added or not. V C 2017Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45367.

Optimization of mechanical properties of glass‐spheres‐filled polypropylene composites for extrusion‐based additive manufacturing

“…a) and prefer to phase‐separate. Therefore, the spheres' contact to PP as well as their specific surface is reduced and, thus, their nucleating ability is diminished . The significantly increased T Cryst of PP/MA/A‐C/am.PO compared to PP/MA/A‐C could be related to the weak interface between the A‐glass and the coating.…”

Simultaneously reinforcing and toughening poly(lactic acid) by incorporating reactive melt‐functionalized silica nanoparticles

“…Improving the crystallinity of PLA has been confirmed to be conducive to the improvement of its mechanical properties . As heterogeneous nucleating points, SiO 2 nanoparticles have also been proved to help the crystallization of polymers . Therefore, to confirm the effect of crystallization behavior on the mechanical properties, the DSC tests were carried out, and the first heating scans of DSC for neat PLA, PLA/p‐SiO 2 , and PLA/f‐SiO 2 are shown in Figure .…”

Hybrid Cellulose–Silica Materials from Renewable Secondary Raw Resources: An Eco‐friendly Method

“…The method applied in this work is very convenient in the energy and resources aspect as a consequence of using secondary raw materials, avoiding deep cleaning of them and also avoiding chemical modification of the inorganic filler in contrast to several working groups that have tried to disperse the filler into the matrix with no big success applying very energy‐demanding methods. Like a recent report where fumed silica nanofillers, like we used in our present method, were processed with modified poly(lactic acid) observed by transmission electron microscopy (TEM) that particle dispersion into the matrix was not improved …”