No abstract

Polypropylene composites containing modified kaolinite were prepared using melt processing and the morphological, thermal, mechanical and their water barrier properties were analyzed. To improve compatibility with polypropylene, kaolinite was modified with silane as a coupling agent. Characterization techniques (X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy) confirmed the effective grafting of these compounds on the surface and edges of the kaolinite with no functionalization on the inner surface. The differential scanning calorimetry and X-ray diffraction techniques demonstrated that the addition of grafted kaolinite affected the iPP crystallinity. The thermogravimetric analysis helped to determine the thermal stability of the composites, being this, dependent on the amount of kaolinite and silane. The stress-strain tests demonstrated an increase in Young's modulus and obtained a 70% reduction in water vapor permeation. These improvements were mainly related to the increased compatibility between the iPP/Kaol interfaces promoted by the silane.Kaol is a dioctahedral lamellar aluminosilicate with molecular formula Al 2 Si 2 O 5 (OH) 4 . 21 This 1:1 clay mineral is very stable, Additional Supporting Information may be found in the online version of this article.

The functionalisation of 2-naphthols and their derivatives has much importance because of their potential pharmaceutical and materials applications. In this context, this work presents a fast, cheap, and efficient method for direct chalcogenylation at position C1 of 2-naphthols promoted by simple bases. The mechanistic studies indicate an ionic mechanism, essentially an electrophilic aromatic substitution, with a key role played by atmospheric oxygen for regeneration of the diorganoyl dichalcogenides.