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

Cyclic olefin copolymer (COC) polymers with rigid ring structures like NB in the polymer chain enhance the toughness greatly, but also cause high brittleness of the material, which limits its application. Modification of COC for toughness by the addition of styrene-butadiene-styrene block copolymer (SBS) and polystyrene-block-poly(ethene-co-butyl-1-ene)-block-polystyrene (SEBS) elastomers of styrene content in SEBS is done. Field emission scanning electron microscope shows that tougheners are uniformly dispersed in the COC matrix without a visible interface between the two phases, which is also supported by the Cole-Cole and Han curves. Rheological behavior indicates that the addition of SBS and SEBS makes the COC/SBS/SEBS composites to have higher elastic modulus, loss modulus, and composite viscosity than that of pure COC. Furthermore, the tensile strength of the composite presents 3.6 times higher than pure COC, while the elongation at break is 6.3 times higher than pure COC. The dynamic mechanical analysis reveals that the COC and tougheners are well blended, and the SBS and SEBS toughen the COC in agreement with the results of morphological and rheological behaviors.

Automated summary

The toughness of cyclic olefin copolymer (COC) is greatly enhanced by adding styrene-butadiene-styrene block copolymer (SBS) and polystyrene-block-poly(ethene-co-butyl-1-ene)-block-polystyrene (SEBS) elastomers, addressing the issue of brittleness. Scanning electron microscope analysis shows uniform dispersion of tougheners in the COC matrix without a visible interface between the phases, supported by Cole-Cole and Han curves. Rheological behavior indicates increased elastic modulus, loss modulus, and composite viscosity in COC/SBS/SEBS composites compared to pure COC. Furthermore, the composite exhibits significantly higher tensile strength and elongation at break. Dynamic mechanical analysis confirms effective blending of COC and tougheners, consistent with morphological and rheological findings.