Preparation and physicochemical analysis of layered silicates modified with silane coupling agents

摘要

Natural Na bentonite contg.65% montmoriilonite and synthetic Na montmorillonite were mixed 2 hrs.in aq.50% EtOH with 2 wt.parts of 3-chloropropyl(I)or 3-methacryloxypro-pyl trimethoxysilane(II).The av.particle size of modified montmorillonite was 10-15)m vs.the Win the original.The II-modified bentonite had particles up to 60 )m.The Inter-layer distance in Na montmorillonite was changed by I only slightly,1.244 vs.1.265 nm,and likewise in bentonite,regardless of the coupler type.Up to 1000 deg C,wt.loss was 1%.In I-or ll-modified montmorillonite,the loss was 2.8 and 4.7% and the DTG peaks at 390-460 and 345-465 deg C,resp.,were attributed to the decompg.silanes.Only the si-lane surface was affected and penetration of silane mols.into the interlayer space was insignificant.