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The 17th international conference on Composite Materials (ICCM-17), Endinburg, UK, July 27-31, 2009

CANCOM 2001 - Third Canadian International Composites Conference from 8/21/2001 to 8/24/2001, Montreal, Quebec, available, unclassified, unlimited

An analytical solution is considered to investigate the bending behavior of cross-ply laminated conical shells using first-order shear deformation theory. Linear strain displacement relation simplified for conical shell is assumed. The governing equations are derived from Hamilton's principle. Assuming Levy-type solution, the governing equations are then converted to ordinary differential equations and changed to state-space form introducing ten unknown variables. The new first-order ordinary differential equation system is solved for displacements using numeric technique. As a loading case, a distributed sinusoidal transverse load is applied. Different lamination sequences including symmetric and asymmetric laminate are studied and compared. The effect of cone angle, various boundary conditions (i.e. clamped, simply supported and free edge), radius to thickness and length to thickness ratio on the displacement of mid surface is investigated., 24th Annual Technical Conference of the American Society for Composites 2009 and 1st Joint Canadian-American Technical Conference on Composites, September 15-17, 2009, Newark, DE, United States

The effect of the dispersion and intercalation/exfoliation of organoclay on the mechanical properties of epoxy nanocomposites was studied. The epoxy resin was EPON™ 828 and the hardener was an amine-terminated polyoxypropylene diol, namely Jeffamine® D-230. The organoclay Cloisite 30B (montmorillonite treated with a quaternary ammonium intercalant) was used. Nanocomposites were prepared by different mixing devices that can generate different shear forces, such as a mechanical stirrer, a microfluidizer, and a homogenizer. The epoxy resin and its nanocomposites were cured at 120°C for 2 hours, with subsequent post cure at 140°C for 2 hours. The tensile and compressive properties of the epoxy resin and its epoxy nanocomposites (ENCs) were determined. The effects of nanoclay on the mechanical properties of the EPON828-D230 system were also investigated by dynamic mechanic analysis (DMA). The results indicate that the modulus increases almost linearly with the clay loading and also is improved with the quality of micro-dispersion, although the latter plays a less important role. On the other hand the strength is very sensitive to the dispersion and only good dispersion can improve the strength, while poor dispersion results in loss of strength. Unlike the modulus, the strength levels off above 4 wt% organoclay loading. It can be concluded that finer and more uniform dispersion increases the clay surface area available for interaction with the matrix and reduces stress concentration in the large aggregates that initiate the failure under stress. It is also observed that the presence of nanoclay C30B does not significantly affect the Tg of the epoxy systems regardless of the level of clay dispersion and clay loading. DMA results also show the positive effect of dispersion and intercalation/exfoliation on the storage modulus of ENCs., Fourth International Symposium on Polymer Nanocomposites Science and Technology (Polymer Nanocomposites 2007), October 17-19, 2007, Boucherville, Québec, Canada

Sixth Canadian International Composites Conference (CANCOM 2007), Winnipeg, Manitoba, August 14-17, 2007

The effect of pre-mixing clay with the epoxy on the dispersion of organoclay in epoxy nanocomposites was studied using different mixing approaches: hand stirring, conventional mechanical stirring, a homogenizer, and a microfluidizer. The epoxy resin and the hardener were EPON™ 828 from Resolution Performance Products and Hunstman Jeffamine® D-230 (an amine-terminated polyoxypropylene diol). The organo-clay Cloisite 30B (montmorillonite treated with a quaternary ammonium intercalant) was used. Epoxy and its nanocomposites were cured either at room temperature for 2 days or at 120°C for 2 hours, with subsequent post-cure at 140°C for 2 hours in both cases. The quality of dispersion and intercalation/exfoliation of organoclay in epoxy after pre-mixing (before adding hardener) was analyzed by means of X-ray diffraction (XRD) and rheological measurement. The dispersion and intercalation/exfoliation of organoclay in the epoxy nanocomposites (ENCs) after curing were characterized by XRD, field emission gun scanning electron microscopy (FEGSEM) and transmission electron microscopy (TEM). To quantify the dispersion, image analysis was also performed. The results indicate that both the pre-mixing and curing steps play a determining role in the dispersion and intercalation/exfoliation of organoclay. During curing, the organoclay can be further intercalated by the epoxy resin quite easily and the intercalation and exfoliation process can continue further or not depending on the curing rate. Although full exfolia-tion of clay cannot be achieved at the pre-mixing stage, this step appears to be very important in controlling the micro-dispersion and thus affecting the further intercalation and exfoliation that take place during the curing step. A well dispersed and well intercalated/exfoliated state of organoclay in ENC can be achieved with a non-solvent-assistance method by using a homogenizer and controlling the curing process., Fourth International Symposium on Polymer Nanocomposites Science and Technology (Polymer Nanocomposites 2007), October 17-19, 2007, Boucherville, Québec, Canada

Sixth Joint Canada-Japan Workshop on Composites, Toronto, Ontario, August 24-26, 2006

Third International Symposium on Polymer Nanocomposites Science and Technology, Boucherville, Québec, September 28-30, 2005

The 5th Canadian International Composites Conference (CANCOM 2005), Vancouver, British Columbia, August 16-19, 2005

The effect of the functionalization of polypropylene by different chemicals on the fabrication and properties of the resulting nanocomposites was studied. Different nanocomposites were prepared using different functionalized polypropylenes (PP) as coupling agents. In order to have better control of the interaction between the functional groups and the clay, samples were mixed in a Brabender plasticorder. The nanocomposite properties were then investigated. Different analysis techniques were used to characterize the dispersion and the properties of the nanocomposites including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction analysis, dynamic mechanical analysis (DMA) and a conventional flexural test.