Copolymers polycarbonate

Another recent development is the preparation of a polyester-polycarbonate copolymer. The polymers involve a polyester component based on the reaction between bis-phenol A and iso- or terephthalic acid with the carbonate component arising from the reactions described in Section 20.3 (see Section 20.9). 

Properties Method Units (Acrylic) (Styrene) Polycarbonate Copolymer... 

The solubility of a solute in scC02 is extremely dependent on its structure, with three features of paramount importance. As expected, compounds of low polarity are more soluble than very polar compounds or salts. However, solubility also increases greatly with increasing vapour pressure of a substrate. To account for the contribution of volatility and solvation to the solubility process, Kurt Zosel coined the term Destraktion (from Latin destillare and extrahere) in his pioneering work on natural product extraction with SCFs [5], Finally, some specific functional groups like perfluoroalkyl and polysiloxane substituents, or polyether/polycarbonate copolymers... 

K. Glasgow and N. Alle, Transparent polymeric compositions comprising polysiloxane-polycarbonate copolymer, articles made therefrom and methods of making same, US Patent 7432327, assigned to SABIC Innovative Plastics IP B.V. (Bergen op Zoom, NL), October 7, 2008. 

It has been noted that C02 behaves very much like a hydrocarbon solvent with regards to its ability to dissolve small molecules consequently, many monomers exhibit a high solubility within C02. On the other hand, most high-molar-mass polymers are scarcely soluble in C02, and the only polymers that show good solubility under relatively mild conditions (T < 373 K, P < 35 MPa) are amorphous fluoropolymers, silicones, and polyether polycarbonate copolymers. 

The elimination of a cyclic intermediate can serve to drive polycondensation forward in special cases. Thus heating the polycarbonate copolymer prepared from ethylene glycol bis(chlorocarbonic acid) and bisphenol A at 280° C in a vacuum leads to elimination of cyclic ethylene carbonate and the formation of the polycarbonate of bisphenol A [46]. 

Potyrailo, R. A. McCloskey, P. J. Wroczynski, R. J. Morris, W. G., High-throughput determination of quantitative structure-property relationships using resonant multisensor system Solvent-resistance of bisphenol a polycarbonate copolymers, Anal. Chem. 2006, 78,... 

Determination of Quantitative Structure-Property Relationships of Solvent Resistance of Polycarbonate Copolymers Using a Resonant Multisensor System... 

Abstract In sensor and microfluidic applications, the need is to have an adequate solvent resistance of polymers to prevent degradation of the substrate surface upon deposition of sensor formilations, to prevent contamination of the solvent-containing sensor formulations or contamination of organic liquid reactions in microfluidic channels. Unfortunately, no comprehensive quantitative reference solubility data of unstressed copolymers is available to date. In this study, we evaluate solvent-resistance of several polycarbonate copolymers prepared from the reaction of hydroqui-none (HQ), resorcinol (RS), and bisphenol A (BPA). Our high-throughput polymer evaluation approach permitted the construction of detailed solvent-resistance maps, the development of quantitative structure-property relationships for BPA-HQ-RS copolymers and provided new knowledge for the further development of the polymeric sensor and microfluidic components. 

The sensor system was applied to the quantification of solvent-resistance of BPA-HQ-RS polycarbonate copolymers in chloroform, THF, and MEK. In a typical experiment, the 6 x 4 sensor array was periodically immersed into the wells containing copolymers in respective solvents. The analytically useful frequency changes were measured upon sensor removal from the solvent and solvent evaporation. Comparison of solvent-resistance of copolymers in the solvents is presented in Fig. 19.6 where data were obtained from measurements of sensor signal change after 46-48 min from the beginning of the experiment. Copolymer solvent-resistance is represented as the absolute sensor frequency shift per mass of polymer in each well... 

Fig. 19.10 Inspection of the pH reagent immobilized in a cellulose acetate film and deposited onto a polycarbonate copolymer material upon immersion in solutions of low (a) and high (b) pH...

Mechanical and optical studies of poly(dimethylsiloxane)bisphenol-A polycarbonate copolymers. J. Polymer Sci B, 7, 579 (1969). 

A capillary lung produced by Dow Chemical Co. (38) can pass 1.4 liters/min/m2 of blood. It has siloxane-polycarbonate copolymer hollow fibers of 150 p inside diameter, 25 /x wall thickness, and is 8.5 cm in active length. Prime volume is 100 ml/m2. One square meter transfers 51 ml/min of oxygen and 66 ml/min of carbon dioxide at 1.4 liters/min/m2... 

Several classes of polymeric materials are found to perform adequately for blood processing, including cellulose and cellulose esters, polyamides, polysulfone, and some acrylic and polycarbonate copolymers. However, commercial cellulose, used for the first membranes in the late 1940 s, remains the principal material in which hemodialysis membranes are made. Membranes are obtained by casting or spinning a dope mixture of cellulose dissolved in cuprammonium solution or by deacetylating cellulose acetate hollow fibers [121]. However, polycarbonate-polyether (PC-PE) block copolymers, in which the ratio between hydrophobic PC and hydrophilic PE blocks can be varied to modulate the mechanical properties as well as the diffusivity and permeability of the membrane, compete with cellulose in the hemodialysis market. 

Silicone-polycarbonate block copolymer. See Silicone-polycarbonate copolymer... 

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