Polycarbonates optical properties

Tjandraatmadja, G.F., Burn, L S., Jollands, M.C. Evaluation of commercial polycarbonate optical properties after QUV-A radiation - the role of humidity in photodegradation, Polymer Degradation and Stability 78 (2002) 435-448... 

Structure and Crystallinity. The mechanical—optical properties of polycarbonates are those common to amorphous polymers. The polymer may be crystallized to some degree by prolonged heating at elevated temperature (8 d at 180°C) (16), or by immersion ia acetone (qv). Powdered amorphous powder appears to dissolve partially ia acetone, initially becoming sticky, then hardening and becoming much less soluble as it crystallizes. Enhanced crystallization of polycarbonate can also be caused by the presence of sodium phenoxide end groups (17). 

Optical Properties. The optical properties of a plastic which are important are refraction, transparency, gloss and light transfer. The reader is referred to BS 4618 1972 for precise details on these terms. Table 1.9 gives data on the optical properties of a selection of plastics. Some plastics may be optically clear (e.g. acrylic, cellulosics and ionomers) whereas others may be made transparent. These include epoxy, polycarbonate, polyethylene, polypropylene, polystyrene, polysulphone and PVC. 

The pace of development has increased with the commercialization of more engineering plastics and high performance plastics that were developed for load-bearing applications, functional products, and products with tailored property distributions. Polycarbonate compact discs, for example, are molded into a very simple shape, but upon characterization reveal a distribution of highly complex optical properties requiring extremely tight dimension and tolerance controls (3,223). 

J. Katajisto, M. Linnolahti, and T.A. Pakkanen, Effect of branching of cyclo-olefin copolymers and polycarbonate polymers on mechanical and optical properties Ab initio and molecular simulation study, /. Mol. Struct., 758(2-3) 189-194, 2006. 

A more sophisticated retardation plate is a film consisting of the perpendicular arranged combination of two optical uniaxial materials, e g., uniaxially stretched polycarbonate foil with a homeotropic oriented LC siloxane layer [18]. The purpose of such a foil is the improvement of the optical properties of LC displays, especially the viewing angle dependence of the contrast. 

Polycarbonate resins are important engineering thermoplastics with good mechanical and optical properties as well as electrical and heat resistance, useful for many engineering applications. Polycarbonates have been commercially produced by the interfacial polycondensation between a bisphenol-A salt in an aqueous caustic solution and phosgene in an organic solution as follows [reaction (13)] ... 

Polycarbonate displays excellent optical properties, with high transparency (transmission 90%), low haze... 

Although polycarbonates have been widely employed as a host material for NLO chromophores (APC in particular), thanks to good optical properties, high 7g, and good processability, there are only few reports about the incorporation of chromophores as a side-chain in a polycarbonate backbone. 

Diphenyl carbonate (DPC) is a carbonate ester of formula (QH50)2C0. The principal use of DPC is as a critical comonomer in the manufacture of polycarbonate resin, an engineering thermoplastic with high impact resistance and excellent optical properties. It is widely used as a heat-resistant and flame-retardant insulator in electronics, a construction material, and an optical material for data storage (CD and DVD disks) and in manufacturing transparent parts in automotive and aerospace industries [1]. 

Comparison of optical density of suspension containing 0.001% of nanocomposite and optical density polycarbonate sample modified with 0.01 % of nanocomposite indicates the proximity of curves character. Thus, the correlation of optical properties of suspensions of nanocomposites and film materials modified with the same nanocomposites is quite possible. 

Duan, 1., Liu, 1., Cornelius, T. W. et al. 2009. Magnetic and optical properties of cobalt nanowires fabricated in polycarbonate ion-track templates. Nuclear Instruments and Methods in Physics Research B 267 2567-2570. 

The optical properties, clarity and gloss, are also improved and biaxially oriented polystyrene and polypropylene films are used for envelope windows and overwraps. Biaxially oriented polyvinylidene chloride film is also used for food packaging in view of its good mechanical and optical properties, but for economic reasons it is only used if its low permeability to gases, especially oxygen, is required. The electrical properties are improved by biaxial orientation and the applications of polyester, polycarbonate and polypropylene films in capacitors are expected to show a rapid growth. In these electrical applications crystalline films are always annealed in order to improve the dimensional heat stability. 

In addition, isosorbide and other l,4 3,6-dianhydrohexitols (isomannide derived from D-mannose, isoidide derived from L-fructose) are also attractive to serve as monomers for polymer production due to their rigidity, chirality, and non-toxicity (Fig. 6). Such features may introduce special properties into the polymers formed, such as enhanced Jg and/or special optical properties. Their innocuous nature also opens the possibility of applications in packaging or medical devices. As a bifunctional monomer, isosorbide can be polymerized with other bifunctional monomers via condensation polymerization. A recent review described various isosorbide-based polymers synthesized, including polyesters, polyamides, poly(ester amide)s, poly(ester imide)s, polycarbonates, polyurethanes, and so on [308], and the present... 

Isosorbide, a double dehydration product derived from sorbitol, is an attractive monomer due to its rigidity, chirality, and non-toxicity. Various isosorbide-based polymers have been synthesized by condensation polymerization, including polyesters, polyamides, poly(ester amides), polycarbonates, and polyurethanes. Incorporation of isosorbide into polymers backbones will introduce special properties, such as enhanced glass transition temperatures and/or optical properties. 

Typical plastics, including polymethylmethacrylate (PMMA), polycarbonate (PC), cyclic olefin copolymer (COC), polysulfone (PSU), polyetheretherketone (PEEK), liquid crystal polymers (LCP), polystyrene(PS), polyethylene terephthalate (PET), etc., have been used for microfluidics. COC is the most commonly used polymer, accounting for around 80 % of all applications, because of its good optical properties [2]. 

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