Thermal and rheological properties of polyethylene composites based on poly(diphenylsiloxanes)/organoclay hybrids obtained from two different silanes

Abstract

Poly(diphenylsiloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nanostructure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR, TG/DTG and SEM. These siloxane‐modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane‐modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to high density polyethylene (HDPE) by melt processing to obtain HDPE/hybrid clay composites which exhibited marked differences on macroscopic properties when compared with neat HDPE.