Comparison of olefin copolymers as compatibilizers for polypropylene and high‐density polyethylene

Abstract

Some polyolefin elastomers were compared as compatibilizers for blends of polypropylene (PP) with 30 wt % high-density polyethylene (HDPE). The compatibilizers included a multiblock ethylene-octene copolymer (OBC), two statistical ethylene-octene copolymers (EO), two propylene-ethylene copolymers (P/E), and a styrenic block copolymer (SBC). Examination of the blend morphology by AFM showed that the compatibilizer was preferentially located at the interface between the PP matrix and the dispersed HDPE particles. The brittle-to-ductile (BD) transition was determined from the temperature dependence of the blend toughness, which was taken as the area under the stress-strain curve. All the compatibilized blends had lower BD temperature than PP. However, the blend compatibilized with OBC had the best combination of low BD temperature and high toughness. Examination of the deformed blends by scanning electron microscopy revealed that in the best blends, the compatibilizer provided sufficient interfacial adhesion so that the HDPE domains were able to yield and draw along with the PP matrix.

Droplet‐in‐Droplet Polymer Blend Microstructures: a Potential Route Toward the Recycling of Co‐mingled Plastics

“…The compatibilized HDPE/PP/PS/PMMA/PC system was compared with the uncompatibilized one and also to the neat materials. In agreement with the literature, compatibilizing the HDPE/PP system results in a higher elongation at break with a reduced tensile modulus, stress at yield and stress at break 63. The uncompatibilized HDPE/PP/PS/PMMA/PC shows a much higher modulus, stress at yield and stress at break than any of the other ternary, binary, or neat systems.…”

Effect of compatibilizing agents on the physical properties of iPP/HDPE organoclay blends

“…Their mixtures exhibit very moderate and unpredictable mechanical properties, due to their influence on many parameters, such as morphology and crystallinity. To improve theses properties, physical or chemical compatibilizers, such as block (or graft) copolymers, or in-situ reactive compatibilizers, have been added to the blend [1][2][3][4][5][6][7]. These compatibilizers contribute to the reduction of interfacial tension, and facilitate the dispersion, stabilize the generated morphology against modification during the processing steps and, in addition, enhance the adhesion between the polymers phases.…”

Understanding the Formation of Linear Olefin Block Copolymers with Dynamic Monte Carlo Simulation

“…[1][2][3][4][5][6][7] OBCs have higher heat and abrasion resistances, and better processability than conventional polyolefin elastomers. [8][9][10][11] Because OBC may have many blocks, mathematical models are needed to quantify how polymerization conditions affect their microstructures. A detailed mathematical model describes how the complex OBC microstructure evolves during polymerization, providing useful insights on how to control these microstructures.…”