Influence of comonomer incorporation on morphology and thermal and mechanical properties of blends based upon isotactic metallocene-polypropene and random ethene/1-butene copolymers

Abstract

Blends of isotactic polypropene (i-PP) with random ethene/1-butene (EB) copolymers containing 10, 24, 48, 58, 62, 82, and 90 wt % 1-butene were prepared in order to examine the influence of the EB molecular architecture on the morphology development as well as on the thermal and mechanical properties. Compatibility between i-PP and EB increased with increasing 1-butene content in EB to afford single-phase blends at a 1-butene content exceeding 82 wt %. The morphology was investigated using AFM and TEM. Improved compatibility accounted for enhanced EB dispersion and interfacial adhesion. Highly flexible as well as stiff blends with improved toughness were obtained.

Rubber–Plastic Blends: Structure–Property Relationship

“…Weimann et al also found that the EBRs with 73 wt% (57 mol%) and 90 wt% (81 mol%) of butene-1, which are obtained by hydrogenation of polybuta dienes with various amounts of 1,2-addition, are miscible with iPP in the molten state as determined by SANS [289]. According to the electron microscopic observation of the morphology in iPP/EBR blends by Mader et al [290], there is no phase separation in the blends with the EBRs with 82 wt% (69 mol%) and 90 wt% (81 mol%) of butene-1. The experimental results are consistent with the theoretical prediction proposed by Lohse and Graessley [291] that EBRs require at least 58 mol% of butene-1 to be miscible with iPP.…”

Correlation of miscibility and mechanical properties of polypropylene/olefin block copolymers: Effect of chain composition

“…This suggests that there is an optimum α‐olefin content in random ethylene/α‐olefins copolymers for maximum iPP impact toughness. It should be noted that at the optimum α‐olefin level for the study in reference,9 the random copolymer was amorphous. Using the PRISM theory proposed by Schwiezer and Singh,10 Lohse predicted the miscibility of polypropylene and ethylene‐α‐olefin copolymer blends 11.…”

“…Maeder et al . studied the influence of comonomer content on the morphology and mechanical properties of iPP/metallocene‐EB blends9 and found that with increasing the 1‐butene content in EB, the compatibility of iPP/EB blends was improved, resulting in better dispersion of EB and stronger interfacial adhesion; more specifically, a single phase was observed at a 1‐butene content exceeding 69.9 mol %. Maeder further noted that the iPP/EB blends exhibited optimum impact toughness when an EB with a 1‐butene content of 31.6 mol % was used.…”

Influence of Copolymer Composition and Curing on Toughness of Isotactic Polypropene Blended Together with Metallocene-EPDM and Ethene/Propene/Vinylcyclohexane Terpolymers

“…[28] pene and ethene/1-olefin copolymers covering the entire copolymer composition including terpolymers with diene and other 1-olefin comonomers without sacrificing narrow molecular mass distribution. At constant incorporation of termonomers the ethene/propene ratio of EPDM elastomers can be varied systematically.…”