Effect of silane concentration on the properties of crosslinked linear low density polyethylene‐montmorillonite nanocomposite

Abstract

In this study, linear low density polyethylene (LLDPE) was grafted and crosslinked by reactive extrusion melt compounding using different silane concentration with and without the presence of montmorillonite (MMT) nanoclay.The effects of different silane concentration and the addition of nanoclay filler on the degree of crosslinking, mechanical, thermal, rheological, and morphological properties were investigated and reported. Gel content results for all

The influence of flame retardant filler on the mechanical, thermal, rheological and flame retardancy properties of silane crosslinked linear low density polyethylene/low density polyethylene blend nanocomposite

“…According to the FTIR spectra shown in Figure 8, the observed peaks at 2850 and 2900 cm À1 presented in all spectra are generally to polyethylene, and the main differences between the crosslinked LLDPE/LDPE blend samples and virgin LLDPE/LDPE blend are peaks at 1100, 1550, and 1650 cm À1 . 4 The characteristic peaks at 1100 cm À1 is due to Si-O-Si stretching vibrations, while peaks at 1550 and 1650 cm À1 are due to bending vibration of -OH group. However, it is worth mentioning that some of the peaks in silane crosslinked LLDPE/LDPE blend could be overlapping with the other peaks of virgin LLDPE/LDPE due to existing of other similar groups.…”

“…For instance, the crosslinked samples containing ATH filler without the presence of MMT (Figure 2a), elongation at break of virgin LLDPE/LDPE blend was decreased from 75% to 28% for virgin LLDPE/LDPE blend and crosslinked sample blend XL/FR20, respectively. The reduction of elongation at break for virgin LLDPE/LDPE blend after crosslinking with ATH filler addition could be attributed to the formation of strong crosslinked network between LLDPE/LDPE blend and ATH filler which limits polymer chain movement; and reduces the flexibility of polymer chains causing lower elongation at break, 4 also this reduction of elongation at break could be due to filler particles agglomeration in the crosslinked blend matrix. It was also noted that similar reduction of elongation at break was observed for crosslinked LLDPE/LDPE blend samples containing ATH filler with the presence of MMT nanoclay compared to virgin LLDPE/LDPE blend sample as shown in Figure 2b.…”

“…The influence of ATH filler on the crosslinked blend matrix and strong significant improvement adhesion between the ATH filler and crosslinked blend interface have been shown, which finally causes strong interfacial bonding and crosslinked network. 4,28 This could be attributed the less mobility of the polymer chains due to effects of ATH filler incorporation into crosslinked blend matrix and formation of strong crosslinked network, which as a result decreases the polymer ductility and eventually increases Young's modulus of virgin LLDPE/LDPE blend. [29][30][31] Furthermore, SEM images (fractured tensile tested samples) shown in Figure 4 have further elaborated the ATH filler and MMT nanoclay influence on the mechanical properties.…”

“…1 Therefore, with the help of crosslinking technique particularly silane crosslinking process, which is the most cost effective crosslinking process, can extend the use of PE by raising its operating limit at high temperatures and improving its chemical resistance, thermal, and mechanical properties, which is due to the formation of a three dimensional macromolecular structure. [2][3][4][5][6] Furthermore, most polymers currently in use for medium and low voltage cables applications are petroleum-based polyolefin such as PE, 2 which are combustible and flammable, and could present a substantial fire hazard without further modification. [7][8][9] Hence, in order to make them suitable for fire protection application, further modifications to reduce their flammability through incorporating flame retardant (FR) additives during the polymer processing and compounding are critically important and essential.…”

“…However, it will lose some valuable and critical physical properties at higher temperature, which restricts its application, in particular with respect to heat deformation resistance and stress cracking 1 . Therefore, with the help of crosslinking technique particularly silane crosslinking process, which is the most cost effective crosslinking process, can extend the use of PE by raising its operating limit at high temperatures and improving its chemical resistance, thermal, and mechanical properties, which is due to the formation of a three dimensional macromolecular structure 2–6 . Furthermore, most polymers currently in use for medium and low voltage cables applications are petroleum‐based polyolefin such as PE, 2 which are combustible and flammable, and could present a substantial fire hazard without further modification 7–9 .…”