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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.
Like many closely related phenol antioxidants, BHT has low acute toxicity [6] (e.g., the desmethyl analog of BHT, 2,6-di-tert-butylphenol, has an LD 50 of >9 g/kg [11]). The US Food and Drug Administration classifies BHT as generally recognized as safe (GRAS) food preservative when used in an approved manner.
2,4-Di-tert-butylphenol (2,4-DTBP) is a white solid with a phenolic odour. It is primarily used as a raw material for the production of several commercially important antioxidants and phenolic benzotriazole -type UV absorbers .
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.
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.
The oxidation of 2,4,6-tri-tert-butylphenol in the alkaline to the intensely blue-colored phenoxy radical can also occur with potassium ferricyanide. [1] [9] [6] The 2,4,6-tri-tert-butylphenoxy radical forms blue crystals on cooling to -70 °C which are stable at room temperature for several weeks and only gradually turn yellow. [9]
The health effects of BPA have been the subject of prolonged public and scientific debate. [12] [13] [14] BPA is a xenoestrogen, exhibiting hormone-like properties that mimic the effects of estrogen in the body. [15] Although the effect is very weak, [16] the pervasiveness of BPA-containing materials raises concerns, as exposure is effectively ...
In polymer chemistry, polymerisation inhibitors (US: polymerization inhibitors) are chemical compounds added to monomers to prevent their self-polymerisation. Unsaturated monomers such as acrylates, vinyl chloride, butadiene and styrene require inhibitors for both processing and safe transport and storage.