AB ST R ACT : Silylated kaolinites were synthesized at 80ºC without the use of inert gas protection. The method presented started with mechanical grinding of kaolinite, followed by grafting with 3-aminopropyltriethoxysilane (APTES). The mechanical grinding treatment destroyed the ordered sheets of kaolinite, formed fine fragments and generated broken bonds (undercoordinated metal ions). These broken bonds served as new sites for the condensation with APTES. Fourier transform infrared spectroscopy (FTIR) confirmed the existence of ÀCH 2 from APTES. 29Si cross-polarization magic-angle spinning nuclear magnetic resonance spectroscopy ( 29 Si CP/MAS NMR) showed that the principal bonding mechanism between APTES and kaolinite fitted a tridentate silylation model (T 3 ) with a chemical shift at À66.7 ppm. The silane loadings of the silylated samples were estimated from the mass loss obtained by TG-DTG curves. The results showed that the 6-hour ground kaolinite could be grafted with the most APTES (7.0%) using cyclohexane as solvent. The loaded amount of APTES in the silylated samples obtained in different solvents decreased in the order as: nonpolar solvent > polar solvent with low dielectric constant (toluene) > polar solvent with high dielectric constant (ethanol).

No abstract

The rheological and mechanical properties of PVC-lignin blends were studied, and their alterations were investigated after lignin was treated with poly(ethyl acrylate-co-maleic anhydride). The addition of lignin changes the early rheological properties of the blend comparing with PVC control because the rigidity of lignin particles leads to more intensive shearing in the system, but has little effect on its rheology during the equilibrium period. The processing stability slightly decreases with the increase of lignin content in the blend. The mechanical properties of the blends are worse than that of PVC control. The rheological properties of the blends are little influenced after lignin is treated with polyacrylate, but the mechanical properties, especially toughness, are improved, and the maximum impact strength is 37.7 % higher than that of PVC control.