Chlorinated polyethylene (CPE)/ethylene methacrylate copolymer (EMA)/sepiolite nanocomposite via a facile one-step covalent modification technique

Abstract

Graphical Abstract for the article "Chlorinated polyethylene (CPE)/ethylene methacrylate copolymer (EMA)/Sepiolite nanocomposite via a facile one-step covalent modification technique" TOC Facile one-step organo-modification of sepiolite improves polymer-filler interfacial adhesion, thereby advances mechanical property and thermal stability of CPE/EMA/sepiolite nanocomposite. ABSTRACT The work reports a facile one step covalent modification technique of sepiolite needles by in-situ polymerization of ε-caprolactone. The effective modification of sepiolite was confirmed by Fourier transform infrared (FTIR), X-Ray Diffraction (XRD), High Resolution-Transmission Electron Microscopy (HR-TEM) and water contact angle measurement. Nanocomposites of chlorinated polyethylene (CPE)/ethylene methacrylate copolymer (EMA) blend (60/40 ratio) were prepared by melt mixing the polymer blend with the pristine and poly(ε-caprolactone) modified sepiolite (PCL-g-SP). For the ease of comparison, equal filler content in both the nanocomposites was maintained (5 wt%). The effect of modified sepiolite on the mechanical and thermal properties of CPE/EMA blend of 60/40 ratio was precisely studied by ultimate tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). The modified sepiolite based nanocomposite considerably showed a 47.77% improvement in ultimate tensile strength over the neat blend. Besides, a high char yield content of both the nanocomposites and 38.4% and 39.6% increment in the initial degradation temperature (T i ) values of pristine 2 and modified sepiolite based nanocomposites were observed respectively compared to the neat blend system. 3 the silica sheets in sepiolite gives rise to the characteristic structural tunnels and blocks of sepiolite along the fiber axis with a cross section 8 . These tunnels of sepiolite exhibit a sufficient quantity of H 2 O molecules along with certain exchangeable cations such as Na + , K + , and Ca 2+ 9, 10 . Unlike platelet-like clays such as MMT, the needle-like sepiolite is comparatively focused to the lesser extent in the literature. As reported by Mittal et al., the unique needle-like morphology offers an added advantage in terms of mechanical reinforcement over other clays 11 . Also, sepiolite needles proclaimed to display lower needle-to-needle contact area when it is compared to other layered phyllosilicates 12 . In addition to the needle-like morphology, the high surface area (BET 374±7 m 2 .g -1 ) of sepiolite, were demonstrated to act as a reinforcing nano-filler in some polymers 13-17 . As reported by García-López et al., an efficient organic modification of sepiolite is necessary that can drastically reduce filler-filler interaction and improve the polymer-filler interface adhesion 18, 19 . Because of the discontinuity of the external silica sheet of sepiolite, a significant number of silanol (Si-OH) groups are present on its surface 20 . The presence of such silanol groups at the edges of the tunnels increases the likelihood of effective organic...

Design of Alginate-Based Bionanocomposites with Electrical Conductivity for Active Food Packaging

“…The highest value is achieved by CA film, whereas all bionanocomposites have significantly lower contact angles which is a consequence of the sepiolite clay used to disperse the rGO and ZnO-rGO fillers. As observed by other authors, films of alginate loaded with neat sepiolite show a decrease in the water contact angle due to its strong hydrophilic character, explained by the high density of silanol groups (−SiOH) [ 39 , 56 ]. Moreover, as it can be seen in the SEM micrographs ( Figure 1 c), the addition of rGO and ZnO-rGO enhances the film surface roughness, enlarging the surface area and contributing to the increase of surface wettability [ 57 ].…”

Surface Modification of Nanoclays with Styrene-Maleic Anhydride Copolymers

“…The peaks at 1853 and 1776 cm −1 are attributed to the C=O stretching vibration, the bands at 1493 and 1453 cm −1 are ascribed to C=C stretching of aromatic benzene ring. Moreover, the wideness of the peak at 1706 cm −1 and 1656 cm −1 is owing to overlapping of the carbonyl (C=O) stretching vibration with the coordinated bonded water [25]. These new bands show that the kinds of SMA are chemically grafted onto the surface of SEP. As can be seen, SMA-1000 copolymer, possessing higher maleic anhydride content and lower molecular weight than SMA-EF40, is also efficiently grafted to SEP surface, as well as grafted to HNT.…”

“…The discontinuity of the silica sheets in sepiolite leads to the characteristic structural tunnels, which possess silanol groups (Si-OH) at their edges. [25] [26]. In the polar polymeric matrix, these silanolgroups not only improve the interactions between SEP and the host polymer, but also enhance the dispersion of SEP without any kind of modification [27] [28] [29] [30].…”

Sepiolite as a nanofiller to improve mechanical and thermal behavior of recycled high-density polyethylene

“…Comparison of modified sepiolite and unmodified sepiolite in this study revealed no significant difference in the final properties of nanocomposites. 20…”

“…Comparison of modified sepiolite and unmodified sepiolite in this study revealed no significant difference in the final properties of nanocomposites. 20 Although there is a lot of studies [21][22][23] concerning the effect of sepiolite as a nanofiller in PE or its copolymers, to the best of author's knowledge, there is no report of using this nanofiller in combination with recycled material. In this study, we considered for the first time the thermal and mechanical behavior of recycled HDPE nanocomposites containing sepiolite as nanofiller.…”