Polymer Engineering and Science · 2002 · 32 citations · 11 references
Natural SciencesMaterials EngineeringMaterials SciencePolymer ChemistryPolymer EngineeringPolymer MaterialsFracture MechanicsFracture ToughnessPolymer CharacterizationPolymer Phase BehaviorPolymer PhysicsPolymer ThermodynamicsChain Branching ReactionsConstrained Geometry CatalystsFracture Of PolymersMelt FractureMolecular Weight DependencePolydispersity EffectsPolyethylenePolymer Polydispersity Analysis
Abstract The effect of molecular structure (MW, MWD and LCB) on the critical tensile stress (σ c ) for the onset of gross melt fracture (OGMF), proposed in Part I (1) as a material‐dependent criterion for fracture, was determined for a group of polyethylenes varying in structure. These included linear low and high‐density polyethylenes and several materials produced using metallocene and constrained geometry catalysts. It was found that the critical stress is independent of M W , for constant polydispersity but increases with increasing long chain branching and polydispersity. The addition of boron nitride particles had no effect on the σ c up to a level of 0.5% by weight.
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