Failure of particulate reinforced polymers

In this presentation, a review is given on the main effects of mineral part iculate fillers (with an aspect ratio of about unity) on the deformation an d fracture of amorphous and semicrystalline thermoplastic and thermosetting polymers. Elastomeric modifiers, polymer blends, and filled elastomers are not considered here. Fillers are generally used to reduce cost as well as the thermal sensitivity of mechanical properties of the matrix material and to improve, if possible, the strength and roughness. The addition of parti culate fillers influences all stages of the fabrication and use of the resu lting composites. We focus oil the effects of a stiff second phase oil elas tic moduli, matrix structure, and on deformation, creep, and failure mechan isms. As the main mechanisms, particle-matrix: debonding, void formation, a nd matrix microshear yielding are identified Toughness is less sensitive to the quality of adhesion since particle-matrix debonding and formation of v oids can be tolerated. If well controlled, debonding contributes to deforma tion (formation of voids should be well distributed in space and time). Ref erence is also made to the surprising and positive effect of CaCO3 particle s on the toughness and impact resistance of HDPE, which increases at small interparticle distances due to interfacial effects on lamellar growth in th e ligament area.