Influence of Organoclay Structure on Nanostructured Materials Based on Eva

Abstract

This article reports the preparation of a series of EVA nanocomposites employing solution casting methods using different types of organo-modified montmorillonite clay. The effect of the organoclay type on the structural organization and thermal behavior of EVA nanostructured materials were systematically investigated. Regarding thermal behavior, the thermogravimetric analysis showed that the nanocomposites presented a slight decrease in thermal degradation temperature compared to EVA, while differential scanning calorimetry, in general, did not show a significant change in the thermal transition temperatures such as glass transition, melting temperature and crystallization temperature of the nanocomposites, regardless of the type and proportion of organoclay in the systems. With respect to structural aspect, the X-ray diffractograms showed that all systems presented a heterogeneous distribution of the nanoparticles, containing part intercalated. Nuclear magnetic resonance relaxometry data provided complementary information for the X-ray results, showing that the EVA systems containing 5 wt% of both studied organoclays presented a mixture of intercalated and exfoliated structures, evidencing that there was a surface interaction between polymer chains and clay lamellae.

In‐situ growth of layered double hydroxide on montmorillonite nanosheets to improve the flame retardant performance of ABS resin

“…[22] Compared with sodium-based MMT, the lamellar spacing is enlarged, and the presence of the intercalated portion was identified from the shift in the d (001) peak to lower angles, indicating an increase in basal distance as a consequence of the interpenetration of LDH inside the MMT lamellae. [35] This result is in line with the periodic alternating arrangement of LDH and MMT shown in Figure 3C, D Furthermore, there are no (003) reflection peaks of LDH in the pattern of LM, indicating that the layered structure of LDH is not entirely formed because the formamide weakens the interactions between neighboring layers and prevents interlayer growth. [36] All the above results suggest that the hybrid with a periodically alternating layered structure can be obtained by depositing LDH on the surface of exfoliated MMT nanosheets.…”

The Use of Zinc Oxide Nanoparticles in Eva to Obtain Food Packing Films

“…The spin-lattice relaxation data of the systems containing modified nanoparticle, presented differences in relation to the EVA/ZnO systems with 0.25% and 0.5%. In both systems, the nanoparticle modification led to T 1.1 H increase, elucidating decrease of the molecular mobility of the polymer along with the increase of the polymer-nanoparticle interaction and indicating greater dispersion of the oxide in the amorphous area of the material [47] [48] [49], where there is no variation of the percentage of T 1,2 H with nanoparticle modification. These data corroborate the results of DMA, where the analysis indicated that the modification induced an increase in the polymer-nanoparticle interactions.…”

Application of NMR Relaxometry to Study Nanostructured Poly(vinyl alcohol)/MMT/Cephalexin Materials for Use in Drug Delivery Systems

“…Generally speaking, the decrease in the proton spin-lattice relaxation time comes from the clay lamellae's exfoliation because the presence of paramagnetic metals in the presence of clay structure interferes in the near proton relaxation mechanism. The contrary effect in proton relaxation time is expected for the samples containing polymer chains intercalated in the clay lamellae because of the restriction of their molecular mobility [7]- [12].…”