화학공학소재연구정보센터
Polymer, Vol.39, No.16, 3841-3845, 1998
Alkali-catalyzed methanolysis of polycarbonate. A study on recycling of bisphenol A and dimethyl carbonate
Alkali-catalyzed methanolysis of poly[2,2-bis(4-hydroxyphenyl)propane carbonate] (PC) in a mixed solvent of methanol (MeOH) and toluene or dioxane was studied. Treatment of PC pellets (1.27 g) in 2 mi MeOH with a catalytic amount of NaOH (8.5 mol% per one ester unit of PC) at 60 degrees C for 330 min yielded only 7% bisphenol A (BPA). However, in a mixed solvent of MeOH (1 mi) and toluene (1 mi), the analogous treatment for 70 min completely depolymerized PC to give free bisphenol A (96%) in a solid form and dimethyl carbonate (DMC) (100%) in solution. Characteristics of the catalysis are discussed together with the pseudo-first kinetic feature of the depolymerization. Reaction conditions were investigated for the purpose of recycling PC plastics in the form of bisphenol A and DMC.