The addition of kaolin in polypropylene homopolymer (PP) leads to a decrease in impact properties. This is due to the lack of adhesion between the PP and the filler. An interesting way of improving adhesion between the two components is to coat the mineral filler in a latex. The efficiency of the coating operation depend on the chemical nature of the coating agent (i.e, the latex) and the coating conditions. The coating conditions were evaluated by measuring the electrokinetic potentials of the kaolin and latex particles. The different analytical techniques used proved the fixation of the latex onto the kaolin. The results of mechanical testing show that the coating of kaolin leads to an increase in impact strength of 50%.

Offretite has been modified (silanated) with octamethylcyclotetrasiloxane (OMCTS) and tetramethylsiloxane (TMS) using an improved CVD method. The parent and silanated offretites were characterized by scanning electron microscopy, X-ray diffraction, i.r. spectroscopy, microporous volume determination, and stepwise thermal desorption of ammonia. OMCTS and TMS agents transform the more accessible silanol groups into grafted groups, respectively. OMCTS was found to be a suitable agent for the selective silanation of external acidic sites, leading to unilayer grafting of the surface without reducing the internal site number and the intracrystalline zeolite voids.

The rearrangement of styrene oxide into phenylacetaldehyde was studied over various zeolites (H-ZSM-5, HY, H-offretite). It was first shown that both external and internal acidic sites are involved in that easy isomerization. Moreover, a comparative study of the rearrangement of this epoxide and of its hindered analog, l-phenyl-1,2-epoxycyclohexene, on silanated offretite, allowed a discrimination between the activities of these sites.

Various typical acid-catalyzed reactions leading to carbonyl compounds were studied using zeolites taking into account their acidic and shape selective properties. Acylation of aromatic compounds by carboxylic acids over Y zeolites leads to quantitative conversion in acylated derivatives with very high para selectivity. On the other hand, the Fries rearrangement of phenylbenzoate gives mainly ortho hydroxybenzophenone. Zeolites are also efficient catalysts in hydration of various aromatic and aliphatic alkynes leading to the corresponding ketones. The epoxide rearrangement of styrene oxide yields phenylacetaldehyde with high conversion. In this latter case, the use of surface-modified zeolites shows that both external and internal acid sites of the zeolite are involved in liquid phase epoxide conversion.