Effect of layered silicate nanoclay on the properties of silane crosslinked linear low-density polyethylene (LLDPE)

Abstract

Abstract. In the present work, the effect of pristine layered silicate montmorillonite (MMT) nanoclay on the properties of silane-crosslinked LLDPE prepared by melt compounding is investigated. The effect of the sequence of feeding additives (nanoclay and grafting agent) into the mixer on gel content, thermal and mechanical properties were studied. Results demonstrate that the sequence of feeding additives influences the final properties of nanocomposites. For samples prepared by first grafting of silane on LLDPE followed by incorporation of nanoclay into the polymer matrix, the gel content and the rate of crosslinking increased, while the elongation at break decreased. For samples prepared by first mixing nanoclay into the LLDPE matrix followed by the grafting reaction, the rate of crosslinking and the tensile properties did not change significantly. The gel content increased with increasing content of nanoclay for both process routes due to an enhanced permeation of water molecules into the polymer matrix in the presence of polar montmorillonite particles. Wide angle X-ray scattering (WAXS) results proved the intercalation/partial exfoliation morphology of nanoclay in the silane-grafted LLDPE matrix. Differential scanning calorimetry (DSC) data showed multiple melting behaviour for crosslinked samples which is indicative for different crystalline structures of the sol and gel part of the LLDPE matrix.

Structural and mechanical properties of clay nanocomposite foams based on cellulose for the food‐packaging industry

“…The main differences between the nanocomposite foams and cellulose were the appearance of new shoulders at 2923 and 2950 cm −1 from the CH functional groups of the clay particles, new well‐defined OH stretching modes due to clay–cellulose interaction at 3490 and 3440 cm −1 , a new shoulder at 1470 cm −1 coming from the CH functional groups of the clay particles, and also two new peaks at 895 and 924 cm −1 , which were due to the presence of clay (these peaks appeared at 883 and 917 cm −1 in the SM‐MMT spectra) and shifted to higher wave numbers in the composites, with the assumption of stronger interactions between the cellulose matrix and SM‐MMT. A small peak at 1620 cm −1 , corresponding to the bending vibrations of OH groups, was observed for the nanocomposites …”

The efficacy of essential oil components loaded into montmorillonite against Aspergillus niger and Staphylococcus aureus

“…In materials applications, montmorillonite (MMT) is perhaps the most commonly used nanoclay . MMT is an economically viable clay material that can be mined from deposits as a raw mineral and is used in a range of applications due to its high cation‐exchange capacity, swelling capacity and high surface area, which is attributable to the interlayer spaces between its platelets . The platelet thickness of MMT is only 1 nm, but the dimensions of length and width can be hundreds of nanometres, with a majority of platelets in the 200–400 nm range after purification.…”

“…26 MMT is an economically viable clay material that can be mined from deposits as a raw mineral and is used in a range of applications due to its high cation-exchange capacity, swelling capacity and high surface area, which is attributable to the interlayer spaces between its platelets. [27][28][29][30][31][32] The platelet thickness of MMT is only 1 nm, but the dimensions of length and width can be hundreds of nanometres, with a majority of platelets in the 200-400 nm range after purification. Moreover, MMT exhibits interesting properties for the adsorption of organic micropollutants such as phenol, phenolic and other benzene derivatives, pesticides and dyes 32 .…”

Modified Crystalline Structure of Silane-Crosslinked Polyethylene in the Proximity of Nanodiamonds

“…[ 27,28 ] Regarding the effects of crosslinking on the polymer backbone, different results have been reported. γ-radiation in high-density PE has been reported to induce a strain to the backbone large enough to give rise to a 15% increased a -unit cell parameter.…”