Realizing simultaneous high‐temperature strength and low‐temperature elongation in polyolefin elastomer toughened polypropylene via controlling the dispersed phase size

Abstract

The properties of modified polypropylene (PP) materials are closely related to their phase structure. In this work, polyolefin elastomer (POE)-toughened PP materials with different phase structures were designed by using various types of POEs (ethylene-butene 710, 110, ethylene-propylene 6202, ethylene-octene 8200). Then, the effects of phase separation in PP/POE blends on both thermal and tensile properties as well as ultraviolet (UV) resistance were investigated. The results revealed that the POE type hardly affected the melt flow rate, melting or crystallization behavior of the modified PP samples. Moreover, scanning electron microscopy results showed that POE6202 had a smaller dispersed phase size in PP (0.1-0.5 μm), which improved the low-temperature elongation at break. PP/POE110 blends with a larger microdomain (1-5 μm) had better high-temperature tensile strength. Further, when toughened with POE110 and POE6202 simultaneously, modified PP had excellent low-temperature elongation (272%@ À40 C) without sacrificing as much of its high-temperature tensile strength (10.4 MPa@70 C). Finally, Electron Paramagnetic Resonance tests showed that the addition of amorphous POE decreased the intensity of free radicals generated in PP during irradiation and promoted their attenuation during decay. This indicated that the introduction of POE improved the UV resistance of PP.phase structure, polyolefin elastomer, polypropylene, tensile properties, UV resistance | INTRODUCTIONPolypropylene (PP) is an inexpensive versatile commercial thermoplastic with high rigidity and excellent chemical resistance. 1 However, its poor impact performance and low-temperature brittleness 2 limit its industrial application. Polyolefin elastomers (POE), copolymerized with ethylene and an α-olefin, are one of the most commonly used toughening materials due to their excellent toughness and stiffness. 3 The toughening effect is related to the type 4-6 and dosage [7][8][9][10][11] of POE, the molecular weight and its distribution of PP, 12,13 as well as the crystalline structure of PP. [14][15][16] For example, Wang et al. 4 evaluated the effect of the POE type (ethylene/1-octene random copolymer POE8200 and ethylene/propylene copolymer POE6202) on the impact strength of toughened PP, and found that

Optimizing Processing Parameters for NR/EBC Thermoplastic Vulcanizates: A Comprehensive Full Factorial Design of Experiments (DOE) Strategy

“…Polyolefin elastomers (POEs), including ethylene-octene and ethylene-butene copolymers, are gaining recognition as vital additives for enhancing polypropylene (PP) toughness [15,16], offering benefits including high plasticity, aging resistance and chemical stability at low cost. Ethylene-octene copolymers (EOCs), developed through constrained geometry catalyst technology, are distinguished by their precise molecular weight and comonomer distribution, reducing crystallinity and making them excellent impact modifiers for PP [17,18].…”

Tailoring polyamide 6 to exhibit super‐tough behavior and high thermomechanical stability: The role of AES and EPDM‐MA hybridization

“…8 Interest in developing polymer blends that tailor the impact strength of semicrystalline thermoplastics for toughening purposes has grown. [9][10][11] The toughening process increases the ability of a plastic to dissipate deformational energy when mechanically stressed before rupture. 12,13 This process makes it easier to select a polymeric material meeting the demands of engineering applications, especially when a super-tough plastic is desired.…”

“…These consist of physical mixtures of two or more polymers, regardless of possible chemical bonds between the components 8 . Interest in developing polymer blends that tailor the impact strength of semicrystalline thermoplastics for toughening purposes has grown 9–11 . The toughening process increases the ability of a plastic to dissipate deformational energy when mechanically stressed before rupture 12,13 .…”