Novel Synthetic Nanocomposite Materials and Their Application in Polyolefin-Based Wire and Cable Compounds

摘要

A new hybrid nano-material derived from synthetic platy silicates is used with magnesium hydroxide to prepare polyolefin-based halogen free flame retardant (HFFR) wire and cable compounds. Properties are compared to a nanocomposite made using natural montmorillonite with magnesium hydroxide and to a control formulation containing only magnesium hydroxide. X-ray diffraction and transmission electron microscopy are used to evaluate the nanocomposites. Cone calorimetry, pyrolysis-combustion flow calorimetry, UL-94 vertical burn, and thermogravimetric analysis indicate that the new synthetic material gives performance that is comparable to montmorillonite, and better than the control formulation. Limiting oxygen index (LOI) values of the nanocomposites are lower than that of the control, indicating that LOI is not a reliable test for flame retardance of nanocomposites. The new synthetic nano-material is white, highly pure, reproducible in composition, and can be manufactured anywhere. Thus, it provides the benefits of natural montmorillonite without the tradeoffs commonly associated with use of natural inorganic materials in polymer compounds.