Preparation And Characterization Of Two Differently Based Polymer/montmorillonite Nanocomposites

In this thesis, intercalated polypropylene/montmorillonie nanocomposite was prepared by melt intercalation and exfoliated AA-co-AM/montmorillonite nanocomposite was prepared by in-situ copolymerization.HTAB was used to modify Na-montmorillonite(Na-MMT) and the interlayer spacing of MMT increased from 1.2 nm to 3.84nm.In addition, water-soluble monomer was used to in-situ polymerize in the suspension of montmorillonite and exfoliated organic MMT was preprared.Nonpolar polypropylene has bad compatibility with MMT even after organic modification to MMT. So polypropylene(PP) grafting acrylic acid was produced by the suspension grafting method as compatilizer.As PP/MMT nanocomposites prepared from HTAB modified MMT as concerned, the interlayer spacing of MMT is 4.61nm,4.2nm and 4.09nm respectively when the MMT content is 1%,2% and 3%.So,the abtained nanocomposites has intercalated structure. The mechanical tests result showed that when the MMT content is 2% and the compatilizer content is 15%,the PMC has best mechanical property. The izod impact strength is 16.45 kJ/m2 and the tensile strength is 35.77 MPa, increasing 280% and 4.3%, compared with pure PP.The POM photo indicated that the O-MMT can reduce the scale of spherical crystal of PP. The WXRD characterization showed that O-MMT possessed obvious nucleation effect on the crystallization process of B-PP. Jeziorny and Mo methods were used to study the non-isothermal crystallization process. The obtained value of kinetics parameters such as Tp,n,Zc,t1/2, A H, F(t),E showed that the O-MMT has nucleation effect in crystallization of PP and can increases the crystallization temperature of PP, quickens the crystallization velocity, decreases the crystallization activation energy of PP but decreases the crystallization degree of PP at the same time.The effect of initiator and cross-linker on water absorption of obtained superabsorbent nanocomposites was studied. X-Ray diffractograms shows MMT in obtained nanocomposites has exfoliated structure. DSC for the nanocomposites showed the Glass Transition Temperature(Tg) of the nanocomposites increases slightly as the MMT content increases. Water absorption velocity and water retentivity under pressure tests showed the addition of montmorillonite(MMT) canimprove the beginning absorption velocity and water retentivity for pure superabsorbent resin.