Heterophasic copolymers of polypropylene: Development, design principles, and future challenges

Abstract

Initially developed to overcome the limited low-temperature impact resistance of polypropylene (PP) and allow its application in subzero temperatures, the PP/elastomer blends became a very important and industrially relevant material class. Within the last 40 years, a whole range of PP impact copolymers from multireactor processes have been developed that are capable of covering wide application areas. This review summarizes their developmental history and presents options for the in-reactor design of these polymers and their modification by compounding with elastomers and fillers or reinforcements after the polymerization. An overview of the application range is also presented together with a glimpse into the future of this material class.

Joint effects of rotational extrusion and TiO2 on performance and antimicrobial properties of extruded polypropylene copolymer pipes

“…Obviously, there existed a two‐phase structure in the PPR pipes, among which the holes represented the amorphous rubber phase removed easily by the etchant. The similar result was also investigated by other researcher . And due to different lamellar stacking patterns between α‐form crystal and β‐form crystal, after selective etching, the exposed structure of dense α‐form crystal is feint while the loose structure of β‐form crystal can be etched deeply .…”

Improvement of the impact strength of ethylene‐propylene random copolymers by nucleation

“…6 the latter quantity is plotted against crystallization temperature proportional to lamella thickness. A very clear correlation exists between the two quantities for all polymers and if we shift the lines vertically according to overall crystallinity, we could obtain a single correlation, just as it was done before for modulus 14 . Since crystallinity practically does not change with nucleation (see Fig.…”

“…As mentioned above, modulus is determined by crystallinity and lamella thickness 14 and the same applies to yield stress. In Fig.…”

“…The practical importance of fracture resistance is clearly shown also by the number of papers related to it, where single-phase materials like homopolymers 10,11 and random copolymers 12,13 are normally discussed separately from multi-phase impact copolymers 14 . In the former case, the crystalline PP phase can be modified to improve its toughness, while the incorporation of elastomer particles is decisive in the latter.…”

Exploring the Compositional Heterogeneity of Vis‐Broken Impact Poly(propylene) Copolymers by Advanced Fractionation Methods

“…Impact poly(propylene) copolymers (IPCs) have been used extensively for many applications in the automotive, packaging, and electrical appliances industries since these materials have superior properties over traditional poly(propylene) (PP) materials due to their multiphase morphology where ethylene–propylene rubber particles are incorporated in an isotactic poly(propylene) ( it ‐PP) matrix . As such, IPC materials have increased impact strengths and tensile‐fracture properties as compared to it ‐PP.…”