Elastomer / Montmorillonite Nanocomposites Preparation And Modification

In this paper, the general rubbers such as PB, PI, SBR/Organophilic montmorillonite (OMMT) nanocomposites (NC) and the thermoplastic elastomer SBS/OMMT NC is prepared by in-situ polymerization and solution intercalation approach respectively for the first time. Considering the practical application, SBS/OMMT NC is prepared through melt intercalation approach also. And the structure and properties of the NC are analyzed and studied systemically.(1) The PB, PI, SBR/OMMT NC are prepared by anionic polymerization technique through in-situ polymerization. The effects of treating of OMMT, solvent, category of OMMT and stirring conditions are studied and the feasible treating method of OMMT and reaction conditions are established.The structure and morphology of the rubber/OMMT NC are characterized by XRD, TEM, FT-IR and H-NMR, and the results show that the exfoliated NC can be obtained by in-situ polymerization. The micro structures of PB and PI are changed with the OMMT added.The thermal stability properties and dynamic mechanical behavior of the NC are investigated by DSC,TGA and DMA. The results show that the glass transition temperature (T_g) is increased and that the thermal stability, the storage modulus (E') and the loss modulus (E") of NC are improved, but the tan 5 are decreased.The relation of structure and property of NC is studied. The structure and properties of PB, PI, SBR/OMMT NC are compared and it is found that the cling of SBR and OMMT nanofiller and improvement in properties are optimal, and those of PB take second place.(2) The SBS/OMMT NC are prepared by solution intercalation approach for the first time. The effects of stirring, category and content of OMMT and matrix to structure and property of NC are studied systemically. And an optimal stirring time is obtained.The structure and morphology of the thermoplastic elastomers/OMMT NC arecharacterized by XRD and TEM. The results show that dominatingly intercalated structure in NC are obtained. As for SBS, 0MMT-DK1 has most excellent intercalation effect and basal spacings are decreased with the adding content of OMMT. Intercalation effect of star-shaped SBS is better than that of linear SBS. TEM show that a selective intercalation of the styrene blocks of SBS into the silicate galleries.The mechanical properties, dynamic mechanical behavior, thermal stability properties and rheological behavior of the nanocomposite are investigated. Results show that the formation of nano structure in NC affects greatly the properties. Especially for star-shaped SBS, the effect is most notable at the range of 5~8phr OMMT content, and tensile strength of NC is increased and higher than that of pure SBS by 85.5%. But it has almost no effect to linear SBS with adding OMMT. 300% strength of NC are significantly increased than that of SBS and improved with OMMT content added. Elongation at break also increase and it show that excellent elasticity is retained. The addition of OMMT gives an increase of the thermal stability, the dynamic storage modulus, dynamic loss modulus of NC and Tg and tan5 of PS, and decrease of tan5 of PB, but does not affect machining properties.(3) Several types of SBS/OMMT composites are prepared by melt blending using a twin-screw extruder. The structure and mechanical properties of the composites are detailed and systemic researched.I. The optimal preparation condition of all SBS/OMMT composites, including melt temperature and rotation speed, is ascertained.II. Grade of SBS has much effect on the structure of the SBS/OMMT composites. To linear-SBS/OMMT composites, OMMT is dispersed in SBS matrix in nano scale. But to star-SBS/OMMT composites, OMMT is dispersed in micrometer scale in SBS matrix.III. From the mechanical properties of the SBS/OMMT, different SBS/OMMT has different result. To SBS1301/OMMT, the tensile strength increases markedly and the elongation at break increases simultaneously comparing to the pure SBS1301. On the contrary, the mechanical properties of the SBS1401/OMMT, SBS4303/OMMT,...