A new, nonphosgene route to poly(bisphenol a carbonate) by melt‐phase interchange reactions of alkylene diphenyl dicarbonates with bisphenol A

Abstract

This article describes a new, nonphosgene method for the synthesis of poly(bisphenol A carbonate) (PC). The method involves three steps: the reaction of an aliphatic diol with phenyl chloroformate to form an alkylene diphenyl dicarbonate, the reaction of the alkylene diphenyl dicarbonate with bisphenol A to produce an aromatic–aliphatic polycarbonate, and the thermal treatment of the polycarbonate at 180–210°C under a stream of nitrogen with Ti(OBu)4 to give PC and a cyclic alkylene carbonate. The method furnished low to moderate molecular masses of PC upon the complete elimination of the aliphatic moieties. The approach may be considered a new method, based on polycarbonate thermochemical degradation, for the synthesis of cyclic aliphatic carbonates. The obtained polymers were characterized by intrinsic viscosity and IR, 1H‐NMR, and 13C‐NMR spectroscopy. The thermal treatment step was conducted in a glass reaction tube at 180–210°C under a stream of nitrogen, and the reaction was completed by heating to 250°C. In the thermal treatment step, semisolid effluents composed of cyclic alkylene carbonates were formed and subsequently eliminated from the reaction mixture. Heating to 250°C under nitrogen or under a dynamic vacuum furnished the pure aromatic PC residue. This intrachange reaction provides a flexible method for the synthesis of polycarbonates with alkylene diols containing two or three methylene groups, from which the pure PC homopolymer can be prepared. The potential of this approach was demonstrated by the successful synthesis of PC homopolymer from five different polycarbonates with a bisphenol A unit linked to 1,2‐propylene, 1,3‐propylene, 2‐methyl‐1,3‐propylene, 2,2‐dimethyl‐1,3‐propylene, and 1,3‐butylene as the alkane chains. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Synthesis and characterization of poly(ether carbonate)s by melt‐phase interchange reactions of dihydroxy compounds with alkylene and arylene diphenyl dicarbonates containing ether groups

“…With the exception of the dihydroxy compounds, the pattern of the 13 C‐NMR spectra for the DIGOL unit, BHEEBPA unit, and OxDiPh unit, in all polycarbonates series was similar to their monomers. The positions of the aliphatic carbon signals in the spectra of all poly(ether carbonate)s containing these unit, were observed at chemical shifts close to those in the monomers 26–28, 32…”

Chemical modification of bisphenol a polycarbonate by reactive blending with ethylene carbonate

“…The knowledge of the reaction mechanism may help to design proper reaction conditions that allow the synthesis of polymers with the desired chemical structure. In addition, it may be applied to the development of other processes, such as for example, the phosgene free synthesis of PC using ETC …”

“…Ethylene carbonate is an important cyclic carbonate and can be used as intermediate or reagent to produce PC by phosgene free routes . For example, in the Ashai phosgene free process, ethylene carbonate (ETC) can be used for the production of methyl carbonate, an intermediate in the production of diphenyl carbonate (DPC) (the monomer used for the melt polymerization process of PC).…”

Palladium‐Catalyzed Carbonylation of Diols to Cyclic Carbonates

“…All cyclic carbonates reported herein have been previously prepared by other methods and characterized by 1 H NMR: ethylene carbonate ( 2a ),9b,31 4‐methyl‐1,3‐dioxolan‐2‐one ( 2b ),9b,31,32 4,5‐dimethyl‐1,3‐dioxolan‐2‐one ( 2c ),9b 4,4‐dimethyl‐1,3‐dioxolan‐2‐one ( 2d ),33 4,4,5,5‐tetramethyl‐1,3‐dioxolan‐2‐one ( 2e ),9b 4‐ethyl‐1,3‐dioxolan‐2‐one ( 2f ),32 4‐phenyl‐1,3‐dioxolan‐2‐one ( 2g ,31,34 4‐(hydroxymethyl)‐1,3‐dioxolan‐2‐one ( 2h ),31a 4‐vinyl‐1,3‐dioxolan‐2‐one ( 2i ),35 4‐(2‐hydroxyethyl)‐1,3‐dioxolan‐2‐one ( 2j ),36 1,3‐dioxan‐2‐one ( 2k ),31b,37 5,5‐dimethyl‐1,3‐dioxan‐2‐one ( 2l ),31b 5,5‐dimethoxy‐1,3‐dioxan‐2‐one ( 2m ),29 benzyl 5‐methyl‐2‐oxo‐1,3‐dioxane‐5 carboxylate ( 2n ),13b…”