The mechanism of chain growth in oxidative polycondensation of phenols

Depolymerization of Poly(2,6-dimethyl-1,4-phenylene oxide) in Green Solvents: Water and Ionic Liquid

The depolymerization of poly(2,6-dimethyl-1,4-phenyleneoxide) (PPO) was accomplished by employing 4-tert-butyl-2,6-dimethylphenol (TBDMP) and 2,6-dimethylphenol (DMP) under oxidative conditions in green solvents: water and ionic liquid. PPO depolymerized to oligomeric products in a faster process within 5 min with TBDMP and within 1 min with DMP in water. In addition to water, an ionic liquid mixture containing the 1-ethyl-3-methylimidazolium cation [C2mim] and a mixture of alkylbenzenesulfonate with xylene sulfonate anion [ABS] was used for the depolymerization of PPO. Depolymerization was successfully achieved in [C2mim][ABS] with TBDMP in a slower process within 3 h.

Voltammetric investigation of diethylstilbestrol

In this work electrooxidation of diethylstilbestrol (DES) was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) using a glassy carbon (GC) electrode. It was statistically shown that both methods could be used for the determination of DES in the concentration range of 2 x 10(-5)-6 x 10(-4) M by CV and 1 x 10(-5)-1 x 10(-3) M in methanol (MeOH) and 4 x 10(-5)-6 x 10(-4) M in acetonitrile (ACN) by DPV and both of the methods could be applied to human serum. A mechanism was proposed about the electrooxidation of this substance.

Voltammetric investigation of beta-estradiol

Electrooxidation of beta-estradiol was investigated using a glassy carbon electrode (GCE) by cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The statistical analysis of the linear relationships between concentration and peak current permits the quantitation of beta-estradiol by both CV and DPV in the concentration range of 4 x 10(-5)-10(-3) M with enough precision and accuracy. A mechanism was proposed about the electrooxidation of this substance. The methods were applied to a tablet form and a transdermal therapeutic system (TTS) of this drug. The results were statistically compared with those of official high performance liquid chromatography (HPLC) method and the differences were found as insignificant.