B. Wessling

Non-equilibrium thermodynamical description of heterogeneous polymer systems (VII):

New Concept for Understanding Brittle-to-Tough Transition in Polymer Blends

Macromol. Symp. 78, 71 - 82 (1994)

A new model for impact modification in polymer blends is being presented. The new model is derived from the new non-equilibrium thermodynamical description of heterogeneous polymer systems and is interpreting crazing fracture energy dissipation and fracture mechanism in a new way: on the basis of dissipative structures in polymer blends and their dynamics.

Formation of flocculated and tubular structures above critical concentration form physically dispersed rubber particles;
"dispersed" means: completely surrounded by a monomolecular matrix polymer layer (dashed line)

Fracture mechanism and energy dissipation: The flocculated rubber network is becoming redispersed by the impact energy; the crack is propagating at the interface between free matrix and adsorbed polymer matrix layer; cavitation occurs at the point where redispersion begins.

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