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.

Remarkably selective formation of macrocyclic aromatic carbonates: versatile new intermediates for the synthesis of aromatic polycarbonates

Abstract: L'hydrolyse/polycondensation interfaciale catalysee par Et 3 N du bis-chloroformiate du bisphenol A donne selectivement des oligocarbonates cycliques avec des temps de reaction courts. Discussion du mecanisme. La polymerisation anionique de ces cyclooligomeres donne des polycarbonates de masse moleculaire elevee

Complex refractive indices measurements of polymers in infrared bands

Abstract: Polymers are widely used in many fields such as radiative cooling, infrared stealth, optical fibers and solar cells. In this work, the complex refractive indices of seven polymers such as polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and polyetherimide (PEI) are measured by spectroscopic ellipsometry (SE) combined with the ray tracing method (RTM) from near-infrared to mid-infrared bands (2–20 µm). The measured results of PDMS have been proved to be accurate by comparing them with previous data in the literature. The obtained refractive indices of polymers in this paper have been compared with the results calculated by the Kramers-Kronig relations. Finally, we analyze the reasons of absorption peaks of these materials in infrared bands by the vibration of chemical bonds in molecules.

Tensile yield‐stress behavior of poly(vinyl chloride) and polycarbonate in the glass transition region

Abstract: The yield-stress behavior of two glassy polymers is studied through the glass transition region over a wide range of strain rates. For temperatures below the glass transition temperature, the yield stress behavior could be described as a non-Newtonian flow in agreement with Eyring's theory, if one excepts a narrow range relating to the slowest strain rates. For temperatures above Tg, the yield-stress behavior is still nonlinear but fits the relations based on the concept of free volume.

Thermal and mechanical behavior of polycarbonate–poly(ethylene terephthalate) blends

Abstract: : Melt blends of polycarbonate and poly(ethylene terephthalate) were formed by continuous extrusion and injection-molded into bars for mechanical testing. Thermal analysis was used to ascertain transitional behavior and the level of PET crystallinity at various points in the fabrication and testing process. The mechanical properties showed little departure from additivity except for the percent elongation at break which was substantially larger for certain blends than expected. Glass transition behavior suggest two amorphous phases for PC rich mixtures and only one mixed phase in the PET rich region. Crystallizability of the PET after the blend was held or prolonged times in the melt stage suggests that interchange reactions do not occur to any great extent. Originator supplied key words include: Poly(ethylene terephthalate)(PET), PC(Polycarbonate), Polyester, Blends, Thermal Analysis, Miscibility, Interchange Reactions, Reprints.

Synthesis and characterization of novel aliphatic polycarbonates

Abstract: A new six-membered cyclic carbonate monomer, 5-benzyloxy-trimethylene carbonate, was synthesized from 2-benzyloxy-1,3-propanediol, and the corresponding polycarbonate, poly(5-benzyloxy-trimethylene carbonate) (PBTMC), was further synthesized by ring-opening polymerization in bulk at 150 °C using aluminum isobutoxide [Al(O i Bu) 3 ], aluminum isopropoxide, or stannous octanoate as an initiator. The results showed that a higher molecular weight polycarbonate could be obtained in the case of Al(O i Bu) 3 The protecting benzyl group was removed subsequently by catalytic hydrogenation to give a polycarbonate containing a pendant hydroxyl group (PHTMC). The polycarbonates obtained were characterized by Fourier transform infrared spectroscopy, 1 H NMR, 13 C NMR, gel permeation chromatography, and DSC. NMR results of PBTMC offered no evidence for decarboxylation occurring during the propagation. The pendant hydroxyl group in PHTMC resulted in an enhancement of the hydrophilicity of the polycarbonate.