The Influence of Graft Length and Density on Dispersion, Crystallisation and Rheology of Poly(ε-caprolactone)/Silica Nanocomposites.

Different techniques of grafting polymer chains to filler surfaces are often employed to compatibilise filler and polymer matrices. In this paper the influence of graft length and graft density on the state of dispersion, crystallisation and rheological properties of poly(ε-caprolactone) (PCL)/silica (SiO) nanocomposites are reported. Grafted silica nanoparticles were prepared through polymerisation of PCL from the nanoparticle surface.

Deformation mechanisms of sub-micrometer thermoplastic vulcanizates obtained by reaction-induced phase separation of miscible poly(ε-caprolactone)/dimethacrylate systems.

The micromechanical deformation mechanisms of sub-μm thermoplastic vulcanizates (TPVs) based on poly(ε-caprolactone) (PCL) and cross-linked methacrylate rubbers were studied by time-resolved small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) measurements in order to better understand the underlying deformation mechanisms responsible for the high elongation at break and good elastic recovery of sub-μm TPVs. It is demonstrated that, in contrast to neat PCL, the interlamellar void formation in the PCL matrix and subsequent coalescence of voids is suppressed by the presence of the rubber (nano)particles in these TPVs. The deformation of the TPVs under tensile conditions is dominated by yielding of the PCL matrix, which is initially localized at the equatorial regions of the rubber particles and progresses towards the polar regions at higher strains.