Viscoelasticity, Tensile Properties, and Microstructure Development in Cyclic Olefin Copolymer/Polyolefin Elastomer Blends

Abstract

The new ethylene/cyclic olefin copolymers (COCs) are a major breakthrough in traditional polyolefins made available by metallocenes, but its high brittleness restricts the applications. Ethylene/1-octene copolymer (POE) with similar backbones is blended with COCs to compensate the rigidity of cyclic segments. Field emission scanning electron microscope photos and Raman spectra demonstrate the existence of abundant phase interfaces between POE and COC, and the phase structure changes from spherical droplets, of partial continuity to cocontinuity with rising POE components. The phase changes are considered as corresponding to the formation, expansion, and coalescence of droplets at melting state according to Van Gurp curves, Han plot, and Cole-Cole plot. Viscoelastic data show that the storage modulus, loss modulus, and complex viscosity reach a high value at medium POE contents. Furthermore, the tensile strength and fracture energy increases and then decreases, the elongation at break increases and Young's modulus reduces with the increment of POE percentage. Because of the large spherical and ellipsoidal structures and abundant interfaces, the synchronous reinforcement and toughness come true at a medium ratio of POEs. Dynamic mechanical analysis confirms the existence of the interfacial layer, and the interfacial layer becomes more pronounced with the rising POE contents exactly as the morphology and rheological findings.

Electrospinning of Cyclic Olefin Copolymer for the Production of Highly Aligned Dye‐Doped Optical Fibers

“…[45] Pure COC has an extremely low tensile strength, and its elongation at break is only 2.7%. [47] These two factors demand harsh conditions for COC to spin. For example, the window of applied voltage was very limited, since high voltage can cause high stretching force of the electric field and thus leads to broken jets, and low voltage may not allow electrospinning to proceed, due to the lack of electrostatic force.…”

Viscoelasticity, Tensile properties, and Microstructure of Cyclic Olefin Copolymer/SBS/SEBS Elastomer Blends

“…In our previous work, Pei et al [33] blended POE with COC, have shown that POE can toughen COC, meanwhile the rigidity of COC is not affected greatly, and COC/POE composites can satisfy the needs of high strength and high toughness applications. In terms of COC toughening, the material of toughening agent is preferably elastomer, and a small amount of elastomer can substantially improve the toughness of COC, and the compatibility between elastomer and COC should be excellent.…”