Polycarbonate

About: Polycarbonate is a research topic. Over the lifetime, 14032 publications have been published within this topic receiving 141740 citations. The topic is also known as: PC & Polycarbonate, PC.

Self-assembled honeycomb polycarbonate films deposited on polymer piezoelectric substrates and their applications

Abstract: Self-assembled honeycomb polycarbonate films were deposited on polymer piezoelectric (poled polyvinylidene fluoride) substrates under a fast dip-coating process. Ordered structures with micro-scaled pores dispersed in the polycarbonate matrix were obtained, demonstrating 2D hexagonal packaging. Theoretical model explaining self- assembling process is proposed. Fabricated structures have a potential as 2D tunable photonic crystals. Photonic bandgap location was estimated. Visible-IR transmittance spectrum of the self-assembled films was studied with a FTIR spectrometer. Diffraction properties of the honeycomb patterns were investigated. High transparency of the components makes possible IR optics applications of obtained structures.

Development of Miscible Blends of Bisphenol A Polycarbonate and Lightly Sulfonated Polystyrene Ionomers from Intrapolymer Repulsive Interactions

Abstract: Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the phase behavior and interactions of blends of the free acid derivative and lithium and sodium salts of lightly sulfonated polystyrene (MSPS) with Bisphenol A polycarbonate (PC). The blends exhibited upper critical solution temperature (UCST) phase behavior and a miscibility window with respect to the sulfonation level. At a fixed blend composition, a minimum in the cloud point temperature occurs at the sulfonation level marking the middle of the miscibility window. The miscibility window depended on the sulfonate cation used. No interactions involving either the carbonate carbonyl group or the sulfonate groups were detected for any of the blends. Miscibility was attributed to intramolecular repulsive interactions within the ionomer.

Characterization of End Groups in Polycarbonates by Reactive Pyrolysis-Gas Chromatography

Abstract: Pyrolysis-gas chromatography using the sample decomposition in the presence of an organic alkali, tetramethylammonium hydroxide (TMAH), was applied for end group determination of industrially available polycarbonate (PC)’s. Various phenolic compounds were observed in the conventional pyrograms of the PC’s, which were formed through the C-C bond cleavage as well as that of carbonate linkages. On the other hand, the PC main chain almost quantitatively degraded through reactive pyrolysis at carbonate linkages to yield the dimethyl derivatives of the constituents such as bisphenol-A through a hydrolytic pyrolysis reaction in the presence of TMAH. In a similar manner, characteristic methyl ethers such as anisole and p-tert-butylanisole were formed from end groups. By this method, highly accurate and rapid determination became possible for the contents of their end groups. This information, in turn, enabled accurate estimation of the number average molecular weight of PC’s without using any reference polymers.

Heterogeneous Cation Exchange Membrane: Preparation, Characterization and Comparison of Transport Properties of Mono and Bivalent Cations

Abstract: Polycarbonate heterogeneous cation exchange membranes were prepared by solution casting techniques using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. The effect of resin ratio loading on properties of prepared membranes was studied. Also, transport properties of the prepared membranes for mono and bivalent cations were evaluated. Scanning electron microscopy and scanning optical microscopy were used for the membranes structure investigation. Images showed that increase of resin ratio in casting solution results in a highly uniform phase to form. Formation and propagation of voids, cavities, and cracks were facilitated through higher resin ratio loading. The water content, surface hydrophilicity, specific surface area, ion exchange capacity, ion concentration, ionic permeability, conductivity, flux, and current efficiency of the membranes were enhanced and their energy consumption, oxidative stability, and mechanical strength were declined by increase of resin rat...

Polycarbonate compositions having improved barrier properties

Abstract: Polycarbonate compositions having improved barrier properties; i.e., low water vapor transmission and low gas permeability, are obtained by employing selected mono- and di-alkyl substituted monomers.