Search results
Results from the WOW.Com Content Network
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.
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.
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.
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]
2,6-di-tert-butylphenol is a precursor to more complex compounds used as antioxidants and light-protection agents for the stabilization for polymers. Of particular note is methyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate (CAS# 6386-38-5), which is formed by the Michael addition of methyl acrylate.
Tris(2,4-di-tert-butylphenyl)phosphite is an organophosphorus compound with the formula [(C 4 H 9) 2 C 6 H 3 O] 3 P. This white solid is a widely used stabilizer in polymers where it functions as a secondary antioxidant. It also reduces discoloration (yellowing) of plastics.
For styrene, nitrophenol compounds such as dinitro-ortho-cresol and di-nitro-sec-butylphenol (DNBP) have long been the important, [7] however they are coming under regulatory pressure due to their high toxicity.