At a laboratory scale, the inorganic PIN flame retardant magnesium hydroxide (MDH) was combined into an organic molecule, producing an organic magnesium salt (OMS). This offers the potential advantages of improving polymer compatibility or of being able to react into the polymer matrix.
The OMS produced, by reaction with pure terephthalic acid (PTA) is an organic molecule with –COOH and –MgOH groups and shows thermal stability up to 400 – 500°C, significantly higher than MDH or PTA. Such approaches may in the future enable the development of a new class of organic – inorganic PINs, with positive fire protection, polymer compatibility and environmental safety. Such products are comparable to natural or synthetic organoclays (which can be synthesised from minerals such as magadiite, bentonite, montmorillonite, smectite …), where the inorganic molecule is modified to become organophilic then loosely bound to an organic compound.
“Synthesis and characterization of novel organic magnesium salt flame retardant”, H. Yan et al., Material Letters, 2014 www.elsevier.com/locate/matlet