Investigation for surface morphology and mechanical property variations of single polymer particles

Abstract

Monodisperse polymer particles were prepared via one-step seeded polymerization using polystyrene, poly(methyl methacrylate), or styrene/methyl methacrylate copolymer [poly(ST-co-MMA)] as seed particles and 1,6-hexanedioldiacrylate or divinylbenzene as crosslinking monomer. For the study, the effects of the combination of seed polymer and crosslinking monomer, the ratio of the absorbed monomer to the seed polymer particles (swelling ratio: S/R), and the seeded polymerization rate on the variation of surface morphology and mechanical properties of polymer particles, such as recovery rate, K-values, breaking strength, and breaking displacement were investigated by using microcompression test. It was observed that the surface morphology could be controlled by changing polymerization rate or combination of seed polymer and crosslinking monomer, and it had a great influence on mechanical properties, especially the breaking strength.

Crosslinking effect on the deformation and fracture of monodisperse polystyrene-co-divinylbenzene particles

“…When compressed to the peak load 20 mN, the particle PSA deforms continuously although a significant displacement burst occurs on the loading segment of PSE. The displacement burst, also called 'pop-in', implies destructive failure of the particles [20]. Whereas the displacement increases a relatively large extent at the pop-in, the contact force drops because infinitesimal counterforce arises from the crushed particle.…”

“…Due to the small volume, spherical geometry and large deformation of polymer particles involved in ACA application, the mechanical characterization of individual micron-sized particles challenges the conventional experimental techniques in aspect of testing scale and resolution [18]. To cope with this, a nanoindentation-based flat punch method has been developed to successfully measure mechanical response of individual particles under compression [19,20]. The deformation behaviour and failure properties of individual metal coated and uncoated polymer particles have been systematically investigated [21][22][23].…”