Influence of processing conditions on dual‐phase continuous blend system of thermoplastic polyurethane with ethylene‐propylene‐diene monomer elastomer

Abstract

In the present work, we extend the investigation on the influence of processing conditions on the morphology, the mechanical properties, and the rheology of the blends of thermoplastic polyurethane (TPU) and ethylene-propylene-diene monomer elastomer (EPDM). Scanning and transmission electron microscopies show that the dual-phase continuous morphology of the blends was strongly dependant on the EPDM composition, processing temperature, and the shear rates. The network structure of the EPDM domain in TPU matrix became finest and most regular for the blends containing 7 wt % EPDM. It was also found that high shear rate favored the formation of the perfect network structure. Furthermore, the blends prepared at 1808C present finer and more perfect network structure than those at the other processing temperatures. The competition of compatible and incompatible segments of TPU with EPDM during melt blending plays an important role in development of the dual-phase continuous morphology. This was reflected through the influence of processing conditions on the rheological properties, and was also verified by the Davies equation's prediction. The tensile properties present a significant improvement with addition of EPDM, and obtained the optimum value for the blends containing 7 wt % EPDM. The influence of different processing parameters on the mechanical properties is associated with their influence on the morphology, and better tensile properties are obtained in the processing conditions, in which, the finer and more perfect network structure of EPDM domain is presented. These facts confirm that the dual-phase continuous morphology is the main advantage for higher tensile strength, elongation at break, and Young's modulus can be well controlled by different processing conditions for the improvement of mechanical properties.

Effects of processing parameters on the properties of microwave‐devulcanized ground tire rubber/polyethylene dynamically revulcanized blends

“…It turned out that the screw speed was the most important parameter which determined the cell size and cell density. In short, the influences of different processing parameters on mechanical properties are associated with their influences on morphology …”

Fabrication of Polyurethane‐Based Composites Used in Water‐Lubricated Bearings

“…Not only lots of valuable nonferrous metals, oil, and a wide range of sources are saved, but also the installation processes have been simplified since the use of WLB. [8][9][10][11][12][13][14][15][16] However, the abrasion resistance of PU elastomer will be dramatically reduced once the sliding friction is generated under high frequency, due to the sharp increase in interior heat generated on the friction surface of PU. [3][4][5][6][7] Polyurethane (PU) is a unique material for its advantages as a combination of the elasticity of rubber and the toughness and durability of plastics.…”

“…strength, oil resistance, load bearing ability, solvent resistance, and abrasion resistance. [8][9][10][11][12][13][14][15][16] However, the abrasion resistance of PU elastomer will be dramatically reduced once the sliding friction is generated under high frequency, due to the sharp increase in interior heat generated on the friction surface of PU. This is the main reason for limiting its use in the industry.…”

“…Polyurethane (PU) is a unique material for its advantages as a combination of the elasticity of rubber and the toughness and durability of plastics. It has been successfully employed in an increasing variety of applications and became one of the most famous polymeric materials because of its outstanding properties, including excellent tensile strength, tear strength, oil resistance, load bearing ability, solvent resistance, and abrasion resistance . However, the abrasion resistance of PU elastomer will be dramatically reduced once the sliding friction is generated under high frequency, due to the sharp increase in interior heat generated on the friction surface of PU.…”

Dynamic mechanical properties and structure of in situ cured polyurethane/hydrogenated nitrile rubber compounds: Effect of carbon black type

“…However, blending with rubbers requires PU to be available in a millable (i.e., rubberlike) or solid form. The few works that have dealt with PU/rubber blends used thermoplastic,1–5 decomposed crosslinked PUs6–8 or millable (peroxide‐ or sulfur‐crosslinkable) PU rubbers 9, 10. Because of the fact that PU precursors are overwhelmingly liquids (i.e., both polyisocyanate and polyol are liquids), researchers have paid less interest to the production of PU/rubber combinations with these urethane precursors 11.…”