Polycarbonate production processes

Fukuoka, S. Kawamura, M. Komiya, K. Tojo, M. Hachiya, H. Hasegawa, K. Aminaka, M. Okamoto, H. Fukawa, L Konno, S. A novel non-phosgene polycarbonate production process using by-product CO2 as starting material. Green Chem. 2003, 5 (5), 497-507. 

We routinely manufacture polycarbonate products by injection molding, blow molding, extrusion, and thermoforming. Injection molding is the most common processing technique. 

Polycarbonates are amorphous polymers with excellent handling properties. Their spectrum of applications ranges from baby bottles to compact discs. Most of the polycarbonate produced is generated by the polycondensation of bisphenol A with phosgene in a biphasic system (sodium hydroxide/dichloromethane). The solution of the polycarbonate product in dichloromethane is washed with water to remove the by-product NaCl. However, in this washing process some 20 g L 1 of the dichloromethane ends up dissolved in the aqueous phase. The dichloromethane must also be removed from the polycarbonate, which is not easy. This means that the polycarbonate will invariably contain some chlorinated impurities, which adversely affects the properties of the polymer. 

Fukuoka, S., Tojo, M., Hachiya, H., Aminaka, M., and Hasegawa, K. 2007. Green and sustainable chemistry in practice Development and industrialization of a novel process for polycarbonate production from CO2 without using phosgene. Polymer Journal, 39 91-114. 

The concept of using a second layer containing LC molecules as in a DSTN display to compensate for the temperature-dependent retardation of STN cells is now applicable also to film-compensated displays. The TCR films can be produced to improve the performance of any STN display in a wide range from room temperature up to 80 °C. The durability of the TCR films is comparable to that of conventional PC retarder films. The advantage of applying the well established and reliable production process for retarder films from polycarbonate by adding a low content of LC silicone is reasonable fix)m the economic point of view also. Thus, the field of application of STN displays, especially STN for car equipment and mobile applications, is expected to be considerably expanded by using these films. 

It is not surprising, given the concurrent research and commercialization efforts that were focused on bringing BPA-based polycarbonates to the market in the late 1950s, that a patent interference arose. Bayer was eventually awarded the first U.S. patents on BPA-based polycarbonates [35] and for the interfacial method of production. GE was issued a patent covering the melt transesterification production process [36]. 

Informative and valuable sections of the chapter are Reengineering the Molecule and the previous sections to which this section refers, Commercial Production of Polycarbonate, Polycarbonate Properties General-Purpose and Apphcation-Specific Grades, Applications using Polycarbonates and Processing Polycarbonate. ... 

Figure 1.11 Fossil energy requirement for petrochemical polymers and PLA. The cross-hatched area of the bars represent the fossil energy used as chemical feedstock (i.e., fossil resource to build the polymer chain). The solid part of the bars represented the gross fossil energy used for the fuels and operation supplies used to drive the production processes. PC = polycarbonate HIPS = high-impact polystyrene GPPS = general purpose polystyrene LDPE = low-density polyethylene PET SSP = polyethylene terephthalate, solid-state polymerization (bottle grade) PP = polypropylene PET AM = polyethylene terepthalate, amorphous (fiber and film grade) ...

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