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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).
Tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate is a chemical compound used as a polymer stabilizer in plastics. Like other hindered phenols it acts as a primary antioxidant. More than 1000 tonnes per year are used in the EU.
Bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite is an organophosphite used as a polymer stabilizer in plastics. Like other phosphite antioxidants it primarily acts to remove hydroperoxides and is typically used in combination with hindered phenolic antioxidants such as pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) .
Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is significantly less volatile than simpler phenolic antioxidants such as butylhydroxytoluene (BHT). This makes it more suitable to stabilising plastics, as it is not driven out by the high temperatures experienced during plastic extrusion and moulding, [2] when they are heated to 150-320 °C (300–600 °F). [3]
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705 mg mL −1: Melting point: −122 to −120 °C; −188 to −184 °F; 151 to 153 K Boiling point: ... 3-Methylheptane is a branched alkane isomeric to octane.
Bisphenol A is difunctional and used to produce epoxy resin and polycarbonate. 4-tert-Butylphenol is monofunctional and so in polymer science terms, bisphenol A is a polymer chain extender but 4-tert-butylphenol is a chain stopper or sometimes called endcapper. It is thus use to control molecular weight by limiting chain growth.
The effect of the tert-butyl group on the progress of a chemical reaction is called the Thorpe–Ingold effect illustrated in the Diels-Alder reaction below. Compared to a hydrogen substituent, the tert-butyl substituent accelerates the reaction rate by a factor of 240. [2] tert-Butyl effect. The tert-butyl effect is an example of steric hindrance.