The Preparation And Application Of High Exfoliated Organic Montmorillonite

As a new type nanocomposites material,polymer/nano-montmorillonite had excellent properties than traditional polymer/inorganic filler material.A small amount of nanomontmorillonite could improve thermal stability and mechanical properties of polymer material obviously.The key to prepare better performance of nanocomposites was the organic montmorillonite(OMMT)nano effects in matrix.As we all know,traditional low active OMMT was modified by alkyl ammonium bromide or alkyl ammonium chloride,and the interlayer spacing of OMMT was 1.5~3.5 nm,which was not significant in composites performance.So how to prepare high stripping degree organic montmorillonite was a difficult problem for modified silicate particles.So far,there were not any literature reporting modified organic inter-layer space of montmorillonite more than 6 nm.The traditional intercalating agents were replaced by cationic waterborne macromolecule polyurethane(CWPU)and Na-MMT was modified successfully by CWPU in this paper.The effects of HOMMT and DOMMT in polyurethane urea(PUU)and rubber were investigated for getting great performance composites.This paper contained three sections as follows:In the first part,the preparation of HOMMT and DOMMT were studied in detail.A novel method that hydroxyl-terminated and carbon-carbon double bonds-terminated WCPU was used.In the condition of ultrasonic,high speed stirring and after washing,filtration,grind,high active HOMMT and DOMMT were obtained.HOMMT and DOMMT were synthesized by fourier transform infrared spectroscopy(FTIR),thermo-gravimetric analysis(TGA),X-ray diffraction(XRD),differential scanning calorimetry(DSC)and transmission electron microscope(TEM)etc.Results showed that the layer spacing of HOMMT modified by active hydroxyl group was 6.29 nm and DOMMT modified by active carbon-carbon double bonds was completely exfoliated.In the second part,a series of PUU/HOMMT nano composites were prepared and the properties of PUU were characterized by TGA,DSC,XRD,FTIR,SEM and TEM etc.Test results showed that when the HOMMT content was about 2wt%,HOMMT particles were uniformly distributed in PUU matrix,and the exfoliated composite structure was got.The mechanical properties and thermal stability of PUU were improved obviously.The tensile strength and elongation at break were increased by 21% and 12% respectively.The glasstransition temperature(Tg)of PUU composites increased by 4.8 ?,and the maximum decomposition temperature of first and second stage were increased by 10.3 ? and 12.7 ? respectively.In the third part,a series of HNBR/DOMMT nanocomposites were prepared.And the effects of active DOMMT on HNBR composites were studied.The properties and structure of HNBR/DOMMT nanocomposites were respectively characterized by SEM,strain-stress machine,akron abrasion machine,TGA,dynamic thermal mechanical analysis(DMA)etc.The results of DSC show that the active double bond of DOMMT produced crosslinking with crosslinker.After active DOMMT was added,the mechanical properties and thermodynamic performance of HNBR nanocomposites improved significantly.When DOMMT content was 3 phr,wear resistance,hardness,tensile strength,and tear strength of nanocomposites increased by 24.7%,6%,4MPa and 30% respectively.DOMMT had crosslinked with HNBR chain in composites.