Study On Structure And Properties Of PP/montmorillonite Nanocomposites

Polymer/montmorillonite(MMT) nanocomposites were a kind of polymer matrix nanocomposites that were studied most and applied for industrialization with good prospect at present. The MMT with structure of a layer of forms are the ideal natural mineral which was prepared into nanocomposites. Presently, the research of Nylon/ MMT nanocomposites have already relatively been deepened. This is because they have inclusive between the polar groups of Nylon and organo-MMT(OMMT). However, PP is a kind of non-polar polymer With MMT being difficult to realize complete intercalation and exfoliation. Therefore, the domestic research about the PP/ MMT nanocomposites were still little. In this thesis, Have made PP intercalate lays of OMMT and exfoliated OMMT into a single layer of slices through melting intercalation, realized the complex on a nanometer of yardstick of PP and OMMT. This research regarded PP grafted MAH as compatibilizer, took the method of masterbatch and use new technologies prepare into high relatively content masterbatch of OMMT, finally, this kind of masterbatch and PP were mixing and melting together and PP/MMT nanocomposites were prepared through pairs of spiral pole, (series PP-B), meantime, PP/MMT nanocomposites without compatibilizer were compared to study (series PP-A).XRD test results showed that PP polymer chains have intercalated lays of OMMT among the series PP-B.TEM observed that OMMT was stripped and close to the single layer of slices; Among the series PP-A, the characteristic diffraction peak of OMMT still appeared the original position, which prove PP polymer chains were too difficult to intercalate directly lays of OMMT, TEM observed that OMMT have serious reunion phenomenon and the majority exist by form who regiment form a cluster. Impact breaking surfaces were observed by SEM, The PP and the series PP-A were shown as the fragilie rupture , the series PP-B were shown as toughness rupture .The crystallization property were investigated by DSC. It was shown that The joining of OMMT has a little effect on melting point of PP, the crystallization temperature of PP was improved obviously and the degree of crystallinity wasincreased; Through studying on kinetics of isothermal crystallization, the constant(k) of crystallization speed and crystallization speed(G1/2) were lowered with rising of crystallization temperature; half period of crystallizations and(tp) were delay with rising of crystallization temperature. The Avrami index(n) of PP value was Between from 2.12 to 2.61, which is in phase nucleating mechanism abviously; the Avrami index(n) of PP-A value was Between from 2.18 to 3.04, which is in phase and out of phase nucleating mechanism; the Avrami index(n) of PP-B value was Between from 2.93 to 3.16, which is out of phase nucleating mechanism typically.The strength and toughness of the PP/MMT nanocomposites were reducing after increasing first with the increase of the content of OMMT . When the content of OMMT is percent 2, tensile strength, flexural strength, flexural modulus and charpy impact strength reached respectively 34.32, 54.69, 2246 (MPa) and 18.26(kJ/m2), which improved separately by 12.8%, 56.6%, 65.1% and 87.5% than PP; The heat distortion temperature was improved by 19 greatestly.