- Source: 1,3,5-Tris(4-(tert-butyl)-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazinane-2,4,6-trione
3/info/1,3,5" target="_blank">1,3,5-3/info/tris(4" target="_blank">Tris(4-(tert-butyl)-3-hydroxy-2,6-dimethylbenzyl)-3/info/1,3,5" target="_blank">1,3,5-triazinane-2,4,6-trione (abbreviated here as Antioxidant 1790) is a speciality antioxidant used to stabilise plastics and synthetic fibres.
Synthesis
It can be synthesised in a 2-step manner. Firstly, 2,4-dimethyl-6-tert-butylphenol is reacted with formaldehyde and HCl (Blanc reaction) to generate a chloromethyl group in the less hindered meta position. This intermediate then reacts with cyanuric acid to give the desired product.
Properties
As each phenol group contains only a single t-butyl group they are considered to have low steric hindrance and thus high activity. Arranging three of these around an isocyanurate core gives a compound with a sufficiently high boiling point that it is not volatilised out of the plastic during plastic extrusion and moulding (up to 320 °C in the case of PA). The isocyanurate core also promotes a high level of crystallinity, which greatly reduces extraction of the antioxidant into water.
Applications
Although it is compatible with polyolefins Antioxidant 1790 is a fairly expensive antioxidant and it is primarily used in speciality applications. It has good compatibility with the engineering plastics, high activity and low colour formation, which makes it common choice in synthetic fibres (polyurethane, polyester and polyamide), particularly elastane.
