Preparation and Properties of LLDPE/PMVS Blends

Abstract

Reactive blending has been carried out by the melt mixing of linear low density polyethylene (LLDPE) and silicone rubber containing vinyl group (PMVS) to obtain grafted and crosslinked blends. Two methods involving the use of free radicals generated from (a) thermomechanical shear and (b) peroxide decomposition were used to prepare the LLDPE/PMVS blends. The occurrence of grafting and crosslinking of the PMVS molecular chains was deduced by considering the mixing torque, solvent extraction data and evidence from the Fourier transform infrared spectra (FTIR), as well as differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The experimental results indicated that reactive blending significantly improved the interfacial adhesion between the two phases and that peroxide decomposition had a higher initiation efficiency in respect of grafting and crosslinking than thermomechanical shear. Thermogravimetric analysis (TGA) showed that reactive blending with PMVS improved the thermal stability of LLDPE. Dynamic rheological behaviour and melt flow rate (MFR) results suggested that grafting and crosslinking between the two components increased the viscoelasticity of the blends and the addition of PMVS improved the processability of the LLDPE. Crosslinking by peroxides gave a higher tensile strength than thermomechanical shear but a lower elongation at break. The limiting oxygen index (LOI) test indicated that the flame retardancy of the LLDPE/PMVS blend increased with increasing amounts of PMVS.

Tensile properties and interfacial adhesion of silicone rubber/polyethylene blends by reactive blending

“…The absorption peaks of the blend located at 2920 and 2850 cm −1 were found to become stronger by heating [Figure (b)], while no significant change was seen in the SR [Figure (a)]. Thus, the absorption peaks at 2920 and 2850 cm −1 shown in Figure (b) are assigned to the stretching vibration of CH 2 group, and the significant change of the peaks is attributed to the chemical reaction of LLDPE during crosslinking of SR by heating . The chemical reaction of LLDPE is induced by free radicals due to the presence of a number of the hydrogen attached to the tertiary carbon atoms .…”

“…Therefore, the adhesion at the interface is significant for the two‐phase blends. To improve the adhesion at the interface of the SR blends, compatibilizer is added in SR/poly(vinylidene fluoride) blends, or reactive blending is carried out in SR/natural rubber, SR/ethylene–octene copolymer, SR/styrene–butadiene rubber, and SR/linear low density polyethylene (LLDPE) blends . For instance, LLDPE has a potential to generate free radicals on the backbone by peroxide, irradiation, – and mechanical shearing .…”

Preparation and Properties of LLDPE/EVA/Nano-ZnO Composites

“…Although the addition of elastomer can greatly improve the toughness of LLDPE, that can also reduce the stiffness and strength [1].…”

Preparation and Process Optimization of LLDPE/EVA/Modified Nano-ZnO Composites

“…However, wider application of LLDPE is limited by some shortcomings. Elastomer and rigid inorganic particles modified LLDPE have their respective advantages [1][2][3]. The research of prepare high toughness and high rigidity nanocomposites by adding elastomers and rigid inorganic particles is of great significance.…”