Structure and mechanical properties of polyamide 6/Brazilian clay nanocomposites

Abstract

and also to evaluate the structure and mechanical properties of the obtained nanocomposites. Experimental MaterialsPolyamide 6 (PA6) was supplied by Rhodia ® /Brazil. The used pristine clay was Na-Montmorillonite clay (MMT, Boa Vista/Paraíba, Northeast of Brazil) supplied by Bentonit União Nordeste with a cation exchange capacity (CEC) of 90 meq.100 g -1 and the interlayer spacing (d 001 ) obtained by XRD was 12.74 Å. MMT was dried at 60 °C for 48 hours prior to use. The used quaternary ammonium salts for the modification of MMT were: alkyldimethylbenzylammonium chloride (Dodigen), hexadecyltrimethylammonium chloride (Genamin), industrial grades supplied by Clariant/Brazil and hexadecyltrimethylammonium bromide (Cetremide), industrial grade from Vetec/Brazil. These salts were used as received according to the literature [7][8][9][10] . Preparation of organoclayThe preparation of the organophilic montmorillonite with Dodigen and Genamin salts was similar: The Na-MMT was mixed in distilled water with stirring to form a uniformly dispersed suspension. The suspension was stirred for 20 minutes after all the clay has been added. And then, the salt equivalent to 1:1 CEC of Na-MMT was added into the dispersion. The mixture was stirred for more 20 minutes. After 24 hours, the mixture of montmorillonite and the salt were washed with distilled water for several times to remove IntroductionPolymer clay nanocomposites are a new class of materials that show improved properties at very low concentration of clay compared with conventional filler composites 1 . Polymer composites have been attracted considerable interest as they offer unusual combinations of physical, thermal, mechanical and other properties that are difficult to obtain from pure polymers. Polymer nanocomposites can be differentiated from traditional polymer composites by the size of the filler. Usually, the particle size of the dispersed phase in the nanocomposites should have at least one dimension in nanometer 2 . Because of the nanoscale features of the filler, nanocomposites possess superior properties over their more conventional microcomposites. These properties can be accomplished at very low concentration of clay (a few %) incorporated in these nanocomposites 3,4 . The key to such performance is related to the ability of exfoliate and disperse individual particles and the high-aspect ratio silicate platelets within the polymer matrix. Recent studies have explored exfoliated structures from organoclays in a wide range of polymer matrices using different processing routes 5 . To date, well-exfoliated composites have been achieved only with a selected number of polymers, for instance, nylon 6, polystyrene, polyimide and epoxies 6 . From these, nylon 6 is particularly unique since exfoliated nanocomposites have been formed by more than one processing technique. The technique of melt processing is particularly attractive due to its versatility and compatibility with existing processing used in the industry for commercial applications 5 . The aim of this wor...

Evaluation of impact strength of polyamide 6/bentonite clay nanocomposites

“…It is interesting to notice that the nanocomposites patterns presented the same behavior regardless the processing variables used. These results are consistent with other works reported in the literature 15,16 .…”

“…They present morphologies composed of exfoliated clay lamellae and well distributed in the polymer matrix. Similar results were observed in the literature 5,10,16 with nanocomposites obtained from commercial clays These images corroborate the results of X-ray diffraction.…”

Hybrid Membranes of Polyamide Applied in Treatment of Waste Water

“…Polyamides are semicrystalline polymers and the presence of peak broadening indicates the existence of amorphous regions. Furthermore, the introduction of clay, regardless of the amount, changes slightly the shape and intensity of the peaks at 20º and 24º of the polyamide6 [30][31][32][33][34][35] . It was found that the addition of 5% w/w of MMT in PA6, cause the appearance of the new reflection at 2θ = From Figure 2, it is noted that the general profile of FTIR spectra of the PA6 remained virtually unchanged, except for a small increase in the intensity of the peaks at wavelengths of 800, 1033 and 1095 cm -1 .…”

“…Probably, the presence of the clay crystalline behavior altered of PA6. However, when small percentages of clay are added to polymer matrices, the degree of crystallinity Xc, increases the nanocomposite which may demonstrate a nucleating effect of the clay 34,35,49 . The SEM images of the top surface and cross section of pure PA6 membranes and their hybrids 1, 3, 5% w/w of MMT, adding 10% w/w CaCl 2 , are shown in figures from 3 to 6.…”

Avaliação do comportamento térmico por DSC na região da pele e do núcleo de amostras injetadas de nanocompósitos de poliamida 6/argila organofílica

“…de processamento adequados, a fim de se obter nanocompósitos intercalados e/ou parcialmente esfoliados. Estes resultados foram confirmados por meio de vários trabalhos já desenvolvidos e apresentados [6,[16][17][18] .…”