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.

Femtosecond Laser Processing of Soft Materials

Abstract: Ablation of polymer films such as polyimide, polycarbonate, polyethylenterephthalate, polytetrafluoroethylene and polymethylmethacrylate were investigated with a Ti: sapphire laser system (150 fs, 800 nm). The single pulse threshold increased from 1.0 Jcm-2 of polyimide to 2.6 Jcm-2 of polymethylmethacrylate. This correlates with the increase of the optical band gap suggesting a multi-photon absorption mechanism. All polymers show incubation effects. A stronger incubation could be found for polycarbonate, polyethylenterephthalate, and polymethylmethacrylate in contrast to the “inert” polymers polyimide and polytetrafluoroethylene due to irreversible chemical alterations. All polymers except polyimide exhibited melting and the generation of vapour yielding swelling. Polyimide only sublimates and/or degrades. Ripples parallel to the electric field vector were generated with linear polarization of repeated laser pulses whereas circular polarization resulted in nanostructure arrays of the order of -100 nm.

Multilayer thermoplastic films and methods of making

Abstract: A method of forming a multilayer film is disclosed, comprising coextruding a first layer comprising a weatherable composition, and a second layer comprising a polycarbonate composition comprising a visual effect filler, wherein the first and second layers are formed by flowing each of the weatherable composition and polycarbonate composition through separate flow channels in a multi-manifold coextrasion die. The shear stress during extrusion on the polycarbonate composition is greater than or equal to 40 kilo-Pascals.

Deposition-induced effects of isotactic polypropylene and polycarbonate composites during fused deposition modeling

Abstract: Purpose Although the feasibility and effectiveness of the fused deposition modeling (FDM) method have been proposed and developed, studies of applying this technology to various materials are still needed for researching its applicability, especially with regard to polymer blends and composites. The purpose of this paper is to study the deposition-induced effect and the effect of compatibilizers on the mechanical properties of polypropylene and polycarbonate (PP/PC) composites. Design/methodology/approach For this purpose, three different deposition modes for PP/PC composites with or without compatibilizers were used for the FDM method and tested for tensile properties. Also, parts with the same materials were made by injection molding and used for comparison. In addition, different deposition speeds were used to investigate the different deposition-induced effects. Furthermore, the behavior of the mechanical properties was clarified with scanning electron microscope images of the fracture surfaces. Findings The research results suggest that the deposition orientation has a significant influence on the mechanical behavior of PP/PC composite FDM parts. The results also indicate that there is a close relationship between the mechanical properties and morphological structures which are deeply influenced by compatibilization. Compared with injection molded parts, the ductility of the FDM parts can be dramatically improved due to the formation of fibrils and micro-fibrils by the deposition induced during processing. Originality/value This is the first paper to investigate a PP/PC composite FDM process. The results of this paper verified the applicability of PP/PC composites to FDM technology. It is also the first time that the deposition-induced effect during FDM has been investigated and studied.

Changes in the properties of Lexan polycarbonate by UV irradiation

Abstract: The changes in the microstructural parameters of Lexan polycarbonate films irradiated with UV radiation at a wavelength of λ = 250 nm were investigated using wide-angle X-ray scattering measurements. The crystal imperfection parameters, such as the crystallite size, lattice strain, and enthalpy, were determined by line profile analysis using the Fourier method of Warren. An exponential function for the column length distribution was used to determine these parameters. UV–Visible spectroscopy study revealed the formation of photo-stabilizers after irradiation. Thermogravimetric analysis revealed that the thermal decomposition temperature increased after the films were irradiated. In the photoluminescence spectrum, the intensities of the peaks at 426 nm in the emission spectra and at 375 nm in the excitation spectra were observed to decrease with an increase in the exposure time. Raman spectra exhibit only minor shifts in some of the bands after the films were irradiated. Atomic force microscopic measurements revealed that the average roughness of the film increased after irradiation. Infrared spectroscopic study revealed that the carbonate linkage was the radiation-sensitive linkage and that the benzene ring does not undergo any changes after being irradiated.