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The Effect of Co‐monomer Type on the Mechanical and Thermal Properties of Metallocene and Conventional LLDPEs
Author(s) -
Walker S.,
Mcnally G.M.,
Martin P.J.
Publication year - 2004
Publication title -
developments in chemical engineering and mineral processing
Language(s) - English
Resource type - Journals
eISSN - 1932-2143
pISSN - 0969-1855
DOI - 10.1002/apj.5500120106
Subject(s) - materials science , composite material , metallocene , branching (polymer chemistry) , ultimate tensile strength , dynamic mechanical analysis , differential scanning calorimetry , rheology , melt flow index , polymer , monomer , thermal analysis , izod impact strength test , thermal , copolymer , polymerization , thermodynamics , physics
A range of metallocene and conventional linear low‐density polyethylenes (LLDPEs), with different material properties, were prepared by injection moulding. An assessment of the effect of cooling rate and polymer properties on the mechanical performance of the specimens was conducted to establish any significant correlations. Tensile results showed that hexane‐based metallocene (m)LLPDEs exhibited higher elongation to break while the Young's modulus of the materials was found to be more influenced by density. Impact results demonstrated that mLLDPEs have superior impact strength at room temperature over conventional LLDPEs. Rheological studies of the materials under high shear rates experienced in injection moulding, were performed to determine flow characteristics of the materials. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were used to study the influence of the co‐monomer type and degree of branching on the properties of the materials.