Results on the Correlation between Molecular Architecture and Rheological Parameters of Metallocene-Catalyzed Polyethylenes

Peng Peng Li; Shi Yuan Yang; Shan Xue

doi:10.4028/www.scientific.net/AMR.550-553.736

Paper Titles

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Experimental Study of Rheological Characteristics of Polymer Melts in the Micro-Die
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Application of a Novel P-N Intumescent Flame Retardant to Polypropylene
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Comparison between Treated and Untreated Zeolite towards the Performance of Polyethersulfone Mixed Matrix Membranes (MMMs) for O2/N2 Gas Separation
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Results on the Correlation between Molecular Architecture and Rheological Parameters of Metallocene-Catalyzed Polyethylenes
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Synthesis and Properties of a High-Molecular-Weight Polyimide Based on 4, 4'-(hexafluoroisopropylidene) Diphthalic Anhydride
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Study on Graft Copolymerization of Maleic Anhydride onto Ground Rubber Tire
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Preparation and Analysis of Homo-Polymer and Copolymer from Tetra-Coordinate Silicate
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Study on Synthesis of a Ampholytic Polyphenylene Sulfide (PPS)
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HomeAdvanced Materials ResearchAdvanced Materials Research Vols. 550-553Results on the Correlation between Molecular...

Results on the Correlation between Molecular Architecture and Rheological Parameters of Metallocene-Catalyzed Polyethylenes

Abstract:

Dynamic rheological results of 17 commercial and noncommercial metallocene-catalyzed polyethylenes, such as shear thinning index(SHI), modulus of crossover point of store modulus and loss modulus (G_co) and flow activation energy(Ea), are presented. The effects of molecular weight distribution(MWD), and degree of short chain branching (SCB) determined by gel permeation chromatography (GPC) and FTIR, were analyzed. Plots of SHI versus MWD revealed the influence of branching level on the shear thinning behavior of polyethylenes. G_co was observed scaling with MWD for metallocene-catalyzed polyethylenes and the correlation between them was generated by MWD=193378*G_co . Correlation between flow activation energy measured by dynamic temperature sweep at low frequency and short chain branch ^-0.9038was also established for metallocene polyethylenes as SCB=7*10^-8*Ea^6.024. Thus, an alternative single rheological method, based on the effect of molecular structural parameters on dynamic rheological behaviors, was proposed to evaluate the polydispersity and short chain branching of metallocene-catalyzed polyethylene.