Morphology evolution and location of ethylene-propylene copolymer in annealed polyethylene/polypropylene blends

Nanoscale chemical characterization of a post-consumer recycled polyolefin blend using tapping mode AFM-IR

“…Previous studies have found that the addition of EPR to a PE/PP blend leads to a finer phase dispersion and improves blend properties such as notched impact strength and ductility. 20 This is attributed to changes in the sub-micron scale, where the EPR forms a layer at the interface between the PE and PP with a core–shell-like morphology, 13,20,23 which is in agreement with our findings.…”

Surface‐directed morphology evolution in ternary blends of polyethylene, polypropylene, and ethylene–propylene copolymer: A study by laser scanning confocal fluorescence microscopy

“…The labeled EPR is designated HY‐EPR. These blends are similar to those studied previously in our group,11, 25 although the compatibilizer falls between the two earlier EPR compositions (60/40 and 80/20 E/P); three‐dimensional (3D) image analysis is used to determine the structure of the EPR interphase, and we compare this with previous results. The most surprising aspect of this work is the evolution of the phase morphology as a function of the annealing time, which bears certain similarities to surface‐directed spinodal decomposition in thin films, including a laminar structure parallel to the film surface and evidence of hydrodynamic flow.…”

“…Other studies have reported that the interpenetrating structure can be converted into the shell morphology by prolonged heating, indicating a kinetic contribution to the nature of the interphase 10. In our research group, we have found that for similar blend compositions and processing conditions, the structure of the interphase is dependent on the composition of the EPR copolymer, which determines its solubility in the PE phase 11, 25. In a blend of 81/14/5 PP/PE/EPR prepared by solution blending and annealed at 175 °C for 310 min, a copolymer with an E/P ratio of 60/40 formed patches on the surfaces of the PE droplets, and this indicated incomplete wetting of the PE phase 11.…”

Role of dissimilar interfaces in thin films of cylinder-forming block copolymers

“…In addition, several types of di-and triblock copolymers are employed as compatibilizers in binary and ternary blends to enhance the macroscopic material properties. [21][22][23] As these copolymers usually migrate to the blends interfaces, this gives rise to a confined situation, and the observed triblock structures at the blend interfaces might be compared to our findings. One problem is that this situation is much more complex than the case of supported films: Apart from the asymmetry in the ͑unknown͒ interface interactions, both interfaces themselves are deformable.…”