Meaning
Morphological configuration consisting of a hard polymer center surrounded by a soft outer layer or vice versa improves the performance of brittle resins. Achieving a core shell domain structure is a standard strategy for toughening polycarbonate or epoxy systems. These particles act as energy absorbers that stop the propagation of cracks during impact.
Impact Modification
Elasticity of the shell layer allows the particle to deform and dissipate energy under sudden load. Rubber-modified grades use this structure to maintain ductility at sub-zero temperatures where the base resin would shatter. The size and concentration of the domains are tailored to the specific toughness requirements of the application.
Optical Property
Transparency remains high when the refractive index of the core shell particle matches the base resin. Unlike simple rubber mixtures, these engineered structures can provide toughness without turning the plastic opaque. This is necessary for automotive lighting and medical housing applications where clarity is a requirement.
Careful design of the particle size keeps it below the wavelength of visible light. The resulting material combines the best features of glass and rubber.
Processing Stability
Resistance to shear during extrusion ensures that the toughening particles do not coalesce or break down. The chemical bonding between the core and the shell prevents the layers from delaminating under high pressure. Stable domains maintain their shape through multiple heat cycles of regrind processing.
