Structure And Properties Of Non-Polar Polymer/OMMT Nanocomposites

Several kinds of non-polar polymer/OMMT having excellent performance were prepared with homemade organic montmorillonite (OMMT) without any compatible agent; they were NR/OMMT, NR/BR/OMMT, NR/SBR/OMMT, EPDM/OMMT, HDPE/OMMT, HDPE/LLDPE/OMMT, LLDPE/OMMT, PP/OMMT nanocomposites. Through X-ray diffraction (XRD) testing, transmission electron microscopy (TEM) observation and other ways, based on the relationship between structure and properties, the species and content of OMMT and the preparation methods were investigated to discuss the effect on the mechanical properties, solvent resistance, thermostability and barrier properties of polymer/OMMT nanocomposites, etc. The main contents are summarized as follows:1. By studying overall performance of several NR/OMMT composites, the best kind OMMT was selected. TEM observation confirmed the preparation of exfoliation NR/OMMT nanocomposites, when the loadings of OMMT was 3.0 phr, the tensile strength of NR/OMMT nanocomposite improved about one-fold, tear strength improved 57%, the oxygen penetration of nanocomposites decreased 49%.2. The NR/BR/OMMT composite were prepared by mechanical blending tostudy the OMMT applications in the tire sidewall. By studying overall performance of several NR/OMMT composites, the optimal OMMT and the best contents of OMMT were chosen. The XRD test and TEM observation confirmed the preparation of exfoliated NR/BR/OMMT nanocomposites; the performance showed that at the best amount of 3.0 phr, the tensile strength and tear strength increased 75% and 54%, respectively; the swelling index reduced 22%, solvent resistance significantly improved. At a typical industrial sidewall rubber formulation, the results show that if 3.0 phr OMMT was added instead of the same HAF carbon black, the performance improved significantly, especially for the sidewall rubber tear strength increased from 48.6 KN/m to 58.8KN/m; and if the common calcium carbonate was added instead of carbon black, it would reduce the costs and keep the performance of the materials.3. The NR/SBR/OMMT composite were prepared by mechanical blending to study the OMMT applications in the tire tread. By studying overall performance of several NR/OMMT composites, the optimal OMMT and the best contents of OMMT were chosen; and preparation of exfoliated NR/SBR/OMMT nanocomposites were confirmed. After 3.0 phr OMMT was added to the tread rubber formulation instead of the same HAF carbon black, the performance improve significantly, especially for the tread rubber, Wear volume are the most critical index of abrasion resistance, it reduced from 0.565 cm3 to 0.483 cm3; and if the common calcium carbonate was added instead of carbon black, it would reduce the costs and keep the performance of the materials.4. TEM observation confirmed exfoliated EPDM/OMMT nanocomposites were prepared by melt extrusion. The mechanical properties indicated that tensile strength of EPDM/OMMT nanocomposites were 5.1 times of pure EPDM systems, and were 3.8 times than that of carbon black system; also the modulus and tear strength significantly improved, when the OMMT content was only 3.0 phr.5. TEM observation showed that the exfoliated HDPE/OMMT nanocomposites were prepared via melt extrusion without any compatible agent. It laid a foundation for PE/OMMT nanocomposites. The mechanical properties of HDPE/OMMT nanocomposites significantly improved, especially the oxygen permeation of HDPE/OMMT nanocomposites films reduced 37%, and it meant gas permeability resistance improved markedly.6. HDPE/LLDPE/OMMT nanocomposites were prepared via direct injection and without any compatible agent semi-exfoliation. With 4.0 wt% OMMT contents, the yield strength and tensile modulus of nanocomposite improved from 25.7MPa and 322.5MPa to 32.8MPa and 491.1MPa compared with those of pure composite, respectively; the bending strength and bending modulus improved 14.2% and 60% than those of pure samples, respectively, when the OMMT content was 6.0 wt%.7. TEM observation showed that the exfoliated LLDPE/OMMT nanocomposite were prepared with the OMMT, which has the big layer distance after second treated. The exfoliation nanocomposite has the best overall performance.8. The polyethylene dripping membrane prepared with OMMT, and the non-drip duration of dripping membrane lengthened from 3-4 months to 7-8 months.9. The intercalated PP/OMMT nanocomposites prepared by melt extrusion with compatibilizer. The intercalation PP/OMMT nanocomposites improved the impact strength 2 times than that of pure PP; simultaneously, the strength, modulus, heat resistance of nanocomposites did not reduce but improve.10. In this paper, the results of non-polar rubber showed as follows: the characteristics of nanocomposites was that NR/OMMT nanocomposites had high performance and with low OMMT contents, simultaneously, it laid the foundation for further applied research. The application of OMMT in the sidewall and tread rubber formulations showed excellent performance in the tire industry with a good application prospects of OMMT. The prepared EPDM/OMMT nanocomposites via extrusion showed high performance; it indicated an application of low hardness and high strength, or high elongation and high strength.11. The research of non-polar plastics showed as follows: the reduction of gases permeability indicated it would prolong the shelf life of vacuum-packed bags, which was prepared with polyethylene and OMMT. High-performance HDPE/LLDPE/OMMT nanocomposites were the shopping plastic bag materials, the improvement of performance would increase the weight of the bag at the same thickness, or it will weight the same things with lower thickness, and this would aim to reduce "white pollution". PE/OMMT dipping membrane solved the existing problem that non-dripless duration was less than a plant cycle duration. The preparation of new type toughened intercalated PP/OMMT nanocomposite showed it had good application prospects at PPR area, because the intercalated PP/OMMT nanocomposite improved the toughness and maintain good heat-resistant and mechanical properties advantage of ordinary toughening.12. In this paper, the theoretical analysis of polymer/montmorillonite nanocomposites research and analysis system, and combined with analysis diagram concluded that the larger OMMT layer spacing, the regular polymer molecular structure and the higher strength of external shear stress would decide the morphology of the prepared nanocomposite. With different morphology of PP/OMMT and EPDM/OMMT nanocomposites were discussed to find the relationship of structure effecting property. The mechanism of the effect of twist, enhancement, compression, barrier and sustained release were demonstrated with schematics. The above theoretical and experimental results will provide the basis for the polymer/montmorillonite nanocomposites research.