Abstract

Bio-polyamide nanocomposites were prepared using the two most viable techniques from the industrial point of view: the melt intercalation process and in situ polymerization. The effect of the synthesis approach and the amount of nanofibre were evaluated in order to check their influence on morphological, thermal and mechanical properties. Regardless of the preparation method, all nanocomposites showed good despersion of nanoclay in polyamide matrix and significant improvements in Young modulus, tensile strenght and heat-distortion temperature were achieved. However, the nanocomposites obtained by in situ polymerization presented higher values since the dispersion of the nanoclay occurs during polymerization, when polymer chains are growing and the viscosity of the matrix is still low.

Abstract

Under the NANOTEK+ project, POLIFLUOR and TECNALIA propose to develop and scale industrially a polyamide obtained by direct synthesis. These properties, mainly thermal ones, have to be improved by the addition of nanoparticles. To this end, it has been worked in the  dispersión of the nanoparticles and the process of polymerization, and in the industrial production process and its evaluation from the point of view of the health security. In-situ polymerization process of anionic polyamide 6 offers important advantages for the incorporation of nanoparticles because the low viscosity of the monomer make easier the dispersion of the nanoscale reinforcemenet. Several parameters of the process  have to be taken into account during the up scaling: Selection of the suitable nanoparticles and their percentage, taking into account the dispersion ability in the matrix and their chemical compatibility. Percentage of catalytic system, which can be affected by the nature of the nanoparticles. Melting, feeding and polymerization temperatures, which should not degrade the nanoparticle. Mixing rates, since the dispersion of the nanoparticles by mechanical stirring can produce air inside the obtaindes polymer. The distribution of the nanomaterial in the polymer matrix and the adhesion degree between both, have studied under formulated material, using techniques such as SEM/EDS. The correct distribution of the nanoparticles in the polyamide 6 has been observed thoughout the industrialization.