Polycarbonate carbon dioxide

HAT Hatanaka M. and Saito, H., In-situ investigation of liquid-liquid phase separation in polycarbonate/carbon dioxide system. Macromolecules, 37, 7358, 2004. 

Carbon Dioxide and Carbon DisulUde. Propylene oxide and carbon dioxide react ia the presence of tertiary amine, quaternary ammonium haUdes, or calcium or magnesium haUde catalysts to produce propylene carbonate (52). Use of catalysts derived from diethyUiac results ia polycarbonates (53). 

Incorporation of carbon dioxide as a reactive comonomer has been studied by several groups. Inoue et al. were the first to succeed in preparing high molecular weight polycarbonates by the copolymerization of carbon dioxide and propylene oxide241,242 ... 

Synthesis of polycarbonates by Mipolynierization of carbon dioxide and glycidyl methacrylate using ionic liquids... 

In our previous work [8], we rqjorted the synthesis of (2-oxo-l,3-dioxolan-4-yl)methacrylate (DOMA) finrn carbon dioxide and glycidyl methacrylate (GMA) using quaternary salt catalysts. In the present work, we studied the catalytic pra rmance of alkyhnethyl imidazolium salt ionic liquid in the synthesis of polycarbonate from the copolyraerization of CO2 with GMA. The influences of copolymerization variable like catalyst structure and reaction tenperature on the conversion of GMA and the yield of the polycarbonate have been discussed. 

Synthesis of polycarbonates from glycidyl methacrylate and carbon dioxide with different... 

Ito and co-workers observed the formation of zinc bound alkyl carbonates on reaction of carbon dioxide with tetraaza macrocycle zinc complexes in alcohol solvents.456 This reversible reaction was studied by NMR and IR, and proceeds by initial attack of a metal-bound alkoxide species. The metal-bound alkyl carbonate species can be converted into dialkyl carbonate. Spectroscopic studies suggested that some complexes showed monodentate alkyl carbonates, and varying the macrocycle gave a bidentate or bridging carbonate. Darensbourg isolated arylcarbonate compounds from zinc alkoxides as a by-product from work on polycarbonate formation catalysis.343... 

Equations 1 to 3 show some of fixation reactions of carbon dioxide. Equations la and lb present coupling reactions of CO2 with diene, triene, and alkyne affording lactone and similar molecules [2], in a process catalyzed by low valent transition metal compounds such as nickel(O) and palladium(O) complexes. Another interesting CO2 fixation reaction is copolymerization of CO2 and epoxide yielding polycarbonate (equation 2). This reaction is catalyzed by aluminum porphyrin and zinc diphenoxide [3],... 

Carbon dioxide can itself be used as a feedstock as well as a solvent for the synthesis of aliphatic polycarbonates by precipitation polymerization. Propylene oxide [39] and 1,2-cyclohexene oxide [40] can both be polymerized with CO2 using a heterogeneous zinc catalyst (Scheme 10.21). 

Carbon dioxide is one of the most abundant carbon resources on earth. It reacts with an epoxide to give either a cyclic carbonate or a polycarbonate depending on the substrates and reaction conditions. Kinetic resolution of racemic propylene oxide is reported in the formation of both cyclic carbonate and polycarbonate. The fe ei value defined as ln[l-(conversion)(l+%ee)]/ln[l-(conversion)(l% ee)] reached 6.4 or 5.6 by using a Co(OTs)-salen complex with tetrabutylammonium chloride under neat propylene oxide or using a combination of a Co-salen complex and a chiral DMAP derivative in dichloromethane, respectively. 

Salen Metal Complexes as Catalysts for the Synthesis of Polycarbonates from Cyclic Ethers and Carbon Dioxide... 

Abstract This chapter focuses on well-defined metal complexes that serve as homogeneous catalysts for the production of polycarbonates from epoxides or oxetanes and carbon dioxide. Emphasis is placed on the use of salen metal complexes, mainly derived from the transition metals chromium and cobalt, in the presence of onium salts as catalysts for the coupling of carbon dioxide with these cyclic ethers. Special considerations are given to the mechanistic pathways involved in these processes for the production of these important polymeric materials. 

Keywords Carbon dioxide Copolymerization Oxetanes Polycarbonates Schiff-base ligands... 

Carbon dioxide is a widely available, inexpensive, and renewable resource. Hence, its utilization as a source of chemical carbon or as a solvent in chemical synthesis can lead to less of an impact on the environment than alternative processes. The preparation of aliphatic polycarbonates via the coupling of epoxides or oxetanes with CO2 illustrates processes where carbon dioxide can serve in both capacities, i.e., as a monomer and as a solvent. The reactions represented in (1) and (2) are two of the most well-studied instances of using carbon dioxide in chemical synthesis of polymeric materials, and represent environmentally benign routes to these biodegradable polymers. We and others have comprehensively reviewed this important area of chemistry fairly recently. Nevertheless, because of the intense interest and activity in this discipline, regular updates are warranted. 

The scope of this chapter will be to focus on well-defined metal complexes that serve as homogeneous catalysts for the production of polycarbonates from epoxides and carbon dioxide. Although there are numerous such well-characterized metal complexes that catalyze this transformation, we will focus this chapter on recent contributions involving metal salicylaldimine (salen) and derivatives thereof [6, 7]. Some of the alternative catalysts systems are very active and selective for copolymer production. Most notably among these are the zinc p-diiminates reported by Coates and coworkers [8, 9]. These systems have been reviewed in detail elsewhere [10]. 

Darensbourg DJ (2007) Making plastics from carbon dioxide salen metal complexes as catalysts for the production of polycarbonates from epoxides and CO2. Chem Rev 107 ... 

Li XH, Meng YZ, Chen GQ, Li RKY (2004) Thermal properties and rheological behavior of biodegradable aliphatic polycarbonate derived from carbon dioxide and propylene oxide. J Appl Polym Sci 94 711-716... 

Lu L, Huang K (2005) Synthesis and characteristics of a novel aliphatic polycarbonate, poly [(propylene oxide)-co-(carbon dioxide)-co-(gamma-butyrolactone)]. Polym hit 54 870-874... 

Liu Y, Huang K, Peng D, Wu H (2006) Synthesis, characterization and hydrolysis of an aliphatic polycarbonate by terpolymerization of carbon dioxide, propylene oxide and maleic anhydride. Polymer 47(26) 8453-8461... 

Zhou M, Takayanagi M, Yoshida Y, Ishii S, Noguchi H (1999) Enzyme-catalyzed degradation of aliphatic polycarbonates prepared from epoxides and carbon dioxide. Polym Bull 42(4) 419 24... 

Polymers from Carbon Dioxide Polycarbonates, Polythiocarbonates, and Polyurethanes... 

Figure 8. Permeability of Lexan polycarbonate to carbon dioxide at 35 °C as a function of C02 partial pressure.Qo, in the presence of 117 mm. Hg of isopentane in the feed , pure C02 Q...

The gas-polymer-matrix model for sorption and transport of gases in polymers is consistent with the physical evidence that 1) there is only one population of sorbed gas molecules in polymers at any pressure, 2) the physical properties of polymers are perturbed by the presence of sorbed gas, and 3) the perturbation of the polymer matrix arises from gas-polymer interactions. Rather than treating the gas and polymer separately, as in previous theories, the present model treats sorption and transport as occurring through a gas-polymer matrix whose properties change with composition. Simple expressions for sorption, diffusion, permeation and time lag are developed and used to analyze carbon dioxide sorption and transport in polycarbonate. 

In Section I we introduce the gas-polymer-matrix model for gas sorption and transport in polymers (10, LI), which is based on the experimental evidence that even permanent gases interact with the polymeric chains, resulting in changes in the solubility and diffusion coefficients. Just as the dynamic properties of the matrix depend on gas-polymer-matrix composition, the matrix model predicts that the solubility and diffusion coefficients depend on gas concentration in the polymer. We present a mathematical description of the sorption and transport of gases in polymers (10, 11) that is based on the thermodynamic analysis of solubility (12), on the statistical mechanical model of diffusion (13), and on the theory of corresponding states (14). In Section II we use the matrix model to analyze the sorption, permeability and time-lag data for carbon dioxide in polycarbonate, and compare this analysis with the dual-mode model analysis (15). In Section III we comment on the physical implication of the gas-polymer-matrix model. 

The solid line in Fig. 1 represents the sorption isotherm of carbon dioxide in polycarbonate calculated by fitting the solubility expression, eq. (11), to experimental data of Wonders and Paul (15). The best fit to the experimental data was achieved with the parameters ao=7.33cm3(STP)/cm3(polymer)-atm and a = 0.161 cm3(polymer)/cm3(STP). As can be seen in Fig. 1, eq. (11) describes the experimental data over the entire pressure range. The algorithm used to fit eq. (11) to the experimental data is described elsewhere (FI). 

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