Influence of the dispersion method of modified layered silicate on the structure and properties of mixed composites based on polyamide and functionalized polyolefin

Abstract

<jats:p>The dependences of the structure and properties of polyamide 6 (PA6) with a functionalized polyolefin (FPO) mixtures on the dispersing method of organically modified clay Cloisite 30В (Cl30В) were studied. The concentration of Cl30B organoclay in PA6/fPO mixtures was constant and amounted to 3.0 wt.%, and the content of fPO varied from 10 to 50 wt.%. Compounding of the mixtures was carried out in the melt using a twin-screw extrusion reactor-mixer. Organoclay was introduced into the composition of the mixtures in two ways: simultaneously with all polymer components (one-stage process) and from the previously obtained Cl30B concentrate into fPO (two-stage process). It is established that the introduction of Cl30B organoclay into the composition of the PA6/fPO mixture using the two-stage technology makes it possible to obtain nanocomposites with increased yield strengths (5–6 %), tensile strength (9–15 %), and elongation at break (1.2–4 times) compared with nanocomposites prepared according to a single-stage technology. At the same time, nanocomposites obtained by a single-stage technology in which PA6 forms a dispersion medium, regardless of the type of incision and the test method, have higher impact resistance (up to 1.2 times) than materials prepared by the two-stage method. This is explained by differences in the degree of dispersion of the nanofiller and the level of interphase interactions between the polymer components and nanoparticles, as a result of which the crystallinity of the components in the mixtures changes, as well as the complex of their rheological and mechanical characteristics. It was also shown that Cl30B organoclay additives, irrespective to the method of its introduction, increase the thermal stability of PA 6/fPO mixtures in comparison with the initial PA6. The results can be used in the development of real technical nanocomposites with improved properties based on PA6 and fPO.</jats:p>