Early process successes and challenges

Fox discovered a method to make BPA-PC via transesterification of the BPA with diphenyl carbonate [38, 39]. Limitations in technology at that time, however, prevented scale-up and commercialization of a melt process to make PC. Instead, the solvent method was commercialized first. 

The first solvent system that was scaled up used pyridine as both solvent and acid acceptor in a system reaction of BPA with phosgene and monofunctional phenol as a molecular weight regulator [40]. This process also met with challenges, since the cost, toxicity, and availabihty of the reaction solvent, pyridine, limited further growth. 

the early process of choice for one of the major producers was the reaction of BPA, phosgene, and monohydric phenols in a methylene-chloride solution in contact with an aqueous solution of sodium hydroxide [41]. For this reaction, a tertiary alkyl amine was the preferred catalyst. Lime was used extensively as the acid acceptor in an alternative process preferred at the time by another major producer [42]. 

As would be expected, the manufacturing processes used to produce polycarbonate from BPA have evolved significantly since the early 1960s. 

Polycarbonates based on BPAand terminated with monofunctional phenols are linear polymers that provide 

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