Effect of the melt flow index of compatibilizer on the melt processing and properties of highly filled magnesium hydroxide/linear low density polyethylene composites

Abstract

The application of highly filled composites is limited by their poor processing and rheological properties due to the high loading of fillers. One possible solution to this problem is to use maleic anhydride grafted polypropylene (MAPP) with high melt index as compatibilizer and lubricant. Herein, magnesium hydroxide (MH)/linear low‐density polyethylene (LLDPE) composites with 60 wt% of MH were prepared using MAPP with three different melt flow indexes (MFI). The equilibrium torque and melt flow index tests show that the addition of MAPP with high MFI significantly improves the processability and flowability of MH/MAPP/LLDPE composites. The rheological studies show that it also leads to a substantial reduction in the viscosity and therefore MH/MAPP/LLDPE composites exhibit more solid‐like responses. The scanning electron microscopy shows that a transition layer is formed at the MH‐LLDPE interface. The flame retardancy test shows that the addition of MAPP slightly reduces the flame retardancy of the composites as evidenced by the reduced limiting oxygen index and increased total heat release. Cone calorimeter test shows that the simultaneous addition of MH and MAPP has a synergistic smoke suppression effect.

Nano and micro co‐filled aluminum nitride/magnesium dihydrate—Silicone rubber composites for high voltage insulation

“…Analogous to ATH, magnesium dihydrate (MDH) filler is another inorganic flame retardant, popularly used in the development of flame‐retardant cables, but sparingly in silicone insulators. MDH is extensively used in cable compounding due to its low cost, exceptional ability to improve flame retardancy, 2–4 reduced smoke generation, 2,5,6 and high thermal stability 7,8 …”

“…Another researcher showed an improvement in LOI up to 35% upon inclusion of 30% by weight of polycarbosilane, a ceramic precursor modified MDH, in polyethylene matrix 3 . In yet another study, the authors have prepared MDH/LLDPE composites with 60% weight loading of MDH using maleic anhydride grafted polypropylene as a compatibilizer 5 . The authors noted a reduction in flame retardancy and a simultaneous improvement in smoke suppression property when tested in cone calorimeter.…”

Synthesis of Zinc Oxide Doped Magnesium Hydrate and Its Effect on the Flame Retardant and Mechanical Properties of Polypropylene

“…As an environment-friendly, non-toxicity, and low-cost flame retardant, magnesium hydrate (MH) has been applied in many flammable polymer matrixes, such as polypropylene (PP) [1,2], polyvinyl chloride (PVC) [3,4], high density polyethylene (HDPE) [5,6], linear low-density polyethylene (LLDPE) [7,8], ethylene-vinyl acetate (EVA) [9,10], polyurethane (PU) [11,12], polystyrene (PS) [13,14], polyethylene terephthalate (PET) [15,16], silicone rubber (SR) [5,17], and so on. However, at the mercy of low flame retardant efficiency, almost all of the polymer/MH composites exhibit good flame-retardant properties with quite a high filler content of MH.…”