Preparation Of Polypropylene-Montmorillonite Nanocomposites By Mother Matrix Method And Polypropylene Grafted Acrylamide By Suspension Method

Polystyrene-montmorillonite nanocomposites (PSMN) were prepared by emulsion polymerization method. XRD, FT-IR, DSC and TGA were used to test PSMN. XRD showed that a centain intercalating effect was achieved by styrene intercalating Na-MMT via emulsion polymerization. The 001 layer spacing of montmorillonite had been enhanced from 1.27nm (Na-MMT) to 1.59nm (PS-Na-MMT). HTAB of Various quality was used to organized Na-MMT and then emulsion polymerization of styrene was processed. The results showed that HTAB played an important role in intercalation. When dosage of HTAB was 40% of Na-MMT, the 001 layer spacing of obtained PSMN achieved 4.37nm. While the 001 layer spacing of O-MMT, which was organized with 40% dosage of Na-MMT, was only 2.96nm. It indicated that HTAB and Styrene had corporate effects on styrene intercalating O-MMT. FT-IR also testified that polystyrene had intercalated the layers of montmorillonite. Results of DSC and TGA showed that thermal properties of PSMN were better than PS.PSMN was melt-mixed with resin mixture in which polypropylene was the main component and polypropylene-montmorillonite nanocomposites were prepared. XRD, mechanic test, POM and SEM were used to test PPMN. XRD spectra indicated that the 001 layer spacing of montmorillonite was increased from 4.37nm (PSMN) to 5.07nm (PPMN) and PPMN was still in intercalating type. The crystals of polypropylene were changed which induced by adding montmorillonite and P crystal of polypropylene was found in PPMN. The mechanic test showed that under the corporate effect of all blending components, PPMN processed good impact property. When the contents of other blending components were fixed, with the content increasing of PSMN, izod impact strength of PPMN was enhanced gradually. When the content of montmorillonite was 2wt%, max value of 36.24kJ/m2 was achieved. If more PSMN was added, izod impact strength of PPMN began to decrease. Adding PSMN had no obvious effect on the tensile strength. From the POM photos of polypropylene spherical crystal, we could see that the polypropylene spherical crystal were diminished obviously, which is one of the two reasons that toughness of PPMN was improved. SEM showed that comparing with typical brittlerupture of polypropylene, the impact surface of PPMN had acuter undulation and more abundant configuration which were typical characters of tough rupture.Besides, suspension grafting of acrylamide onto polypropylene was studied in water medium. The maxium degree of grafting had archieved above 1%. The non-isothermal crystallization kinetics of acrylamide graft polypropylene (PP-g-AM) was studied by means of differential scanning calorimetry (DSC). The results showed that both Jeziorny and Mo methods could describe the non-isothermal crystallization course of PP-g-AM accurately. Avrami exponent didn't change obviously after grafting, which indicated that the crystallization mechanism of PP-g-AM was almost as same as PP. The values of modified Zc of PP-g-AM were a little higher than those of pure PP. The values of F(T) of PP-g-AM were a little lower than those of pure PP, which indicated that PP-g-AM had faster crystallization velocity. This result conformed to the slight degradation of PP chains in grafting process.