Polypropylene (PP) samples functionalized with Maleic Anhydride (MAH) were used as interfacial coupling agents during the preparation of PP based layered silicate nanocomposites (PP-LSN). To prepare these functionalized PP samples, butyl 3-(2-furyl)propenoate (BFA) was used as coagent during the radical post-functionalization with MAH to avoid the polymer degradation. The obtained materials, differing from the functionalization degree (FD) and structure (MW and molecular weight distribution), were accurately characterized and firstly employed as polymer matrices for PP-LSN preparation to study the influence of their architecture on clay dispersion and thus on their intercalation capability. Successively, PP-LSNs were prepared by using PP as matrix and 5 phr of the above compatibilizers. Morphological, thermal, mechanical and thermo-mechanical analyses of the nanocomposites pointed out that the higher molecular weight PP-g-MAH samples allow to achieve simultaneously a good intercalation within the filler and a significant compatibilization with pristine PP chains, leading to high performances PP-LSNs.