The structure and properties of polypropylene (PP) and ethylene propylene copolymer (EPR) blends filled with BaSO4 have been investigated. The aspect of structure control concerned was the separate dispersion of filler and rubber in the PP matrix or encapsulation of the filler in the rubber phase. The former structure prevails in the PP/EPR/BaSO4 systems, and addition of maleic anhydride-grafted polypropylene (MAPP) enhances the adhesion between the PP matrix and the filler. Encapsulation of the filler particles into the elastomer takes place when maleated EPR-rubber (EPMA) is used, and the encapsulated structure prevails even under the severe shearing conditions of injection molding. The improved matrix/filler adhesion resulted in increased yield stress and tensile strength, but decreased impact resistance. The particle size of the filler proved to be a crucial factor; below a certain particle size aggregation becomes a dominating factor. Extensive aggregation leads to the deterioration of all mechanical properties, especially to decreased impact strength.
|Title of host publication||Doktorsavhandlingar vid Chalmers Tekniska Hogskola|
|Publisher||Chalmers Tekniska Hogskola|
|Number of pages||1|
|Publication status||Published - Dec 1 1997|
ASJC Scopus subject areas