Zinc layered hydroxide salts: intercalation and incorporation into low-density polyethylene

Abstract

Abstract:In this study, polymer composites using low-density polyethylene (LDPE) and layered hydroxide salts (LHS) were synthesized. The following compositions of LHS were obtained Zn 5 (OH) 8 (A n-) 2/n .yH 2 O, where A was varied in order to obtain hydrophilic (A = NO 3 -) or hydrophobic (A = DDS --dodecyl sulfate or DBS --dodecyl benzene sulfonate). Synthesis was carried out by co-precipitation in alkaline medium and drying, being followed by characterization via Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy. A variable amount of filler was then incorporated into the LDPE via extrusion, which was then injection molded to obtain specimens for evaluating tensile properties (Young's modulus, tensile strength, strain at break and toughness). For comparison, the sodium salts of the surfactants (NaDDS and NaDBS) were also used as fillers in LDPE. The X-ray diffraction results indicated that the hydrophobic LHS were exfoliated in the polymer matrix, whereas the hydrophilic LHS was only delaminated. In the LDPE composites, melting and crystallization temperatures were nearly constant, along with the crystallinity indexes. The mechanical properties were mainly varied when the organophilic LHS was used. Overall, fillers based on LHS, especially those containing hydrophobic anions, may be interesting alternatives in the production of reinforced thermoplastics.

Synthesis and Characteristics of Valeric Acid-Zinc Layered Hydroxide Intercalation Material for Insect Pheromone Controlled Release Formulation

“…It was found that the full release of VA did not happen as the saturated release was only achieved below 45%. This could be due to the strongly held VA anions by the positively charged layered host, resulting in the low release of VA into the aqueous solution [15]. VAN Intercalation Compound. To determine the release mechanism of VA from the nanohybrid, the controlled release data of VAN were fitted to several kinetic models, namely, pseudo-first order (In ( − ) = In − 1 ) [30] and pseudo-second order ( / = 1/ 2 2 + / ) [33] and parabolic diffusion ((1 − / )/ = −0.5 + ) [32], where and denote the equilibrium release amount and release amount of anion at Figure 7: Fitting the data of valeric acid released from its intercalation compound into distilled water at different pHs using pseudo-first order and pseudo-second order and parabolic diffusion models at (a-c) pH 4, (d-e) pH 6.5, and (g-i) pH 8. any time, , respectively.…”

“…There are various methods reported for the preparation of ZLH nanohybrid such as urea hydrolysis [12], pulse laser-ablation technique [10], exfoliation-restacking route method [9], and chemical bath deposition [13]. Coprecipitation technique which is among the simple synthesis methods that employ less chemical with fewer preparation steps has been frequently adopted in the ZLH nanocomposite synthesis [14,15]. Furthermore, this method uses normal laboratory equipment and no dedicated complex instrumental setup is required.…”

Thermal and flammability properties influenced by Zn/Al, Co/Al, and Ni/Al layered double hydroxide in low‐density polyethylene nanocomposites

“…The compatibility of the inorganic LDHs with LDPE polymer matrix can be increased after a surface chemical modification with the finality to turn LDHs more hydrophobic. Such properties can be achieved by the intercalation of organic anions of hydrophobic aliphatic carbon chains, such as dodecyl sulfate and stearate …”

“…Such properties can be achieved by the intercalation of organic anions of hydrophobic aliphatic carbon chains, such as dodecyl sulfate and stearate. [5][6][7] The flame retardancy characteristics of LDHs originate with layered hydroxide endothermic decomposition, which forms water vapor and residues containing oxides. These residues hinder the burning process by reducing the oxygen supply to the bulk phase and prevent dripping of the burning polymer, avoiding fire propagation.…”

New Alternative to Produce Colored Polymer Nanocomposites: Organophilic Ni/Al and Co/Al Layered Double Hydroxide as Fillers into Low-Density Polyethylene

“…This positive charge is counter balanced by anions in the interlayer region. LDH 18,21 In order to obtain a homogeneous dispersion of individual LDH layers in a polymer matrix, it is desirable to use LDH intercalated with organic anions. These anions make the filler more compatible with the polymer and thus facilitate the penetration of the polymer chains.…”