Transparent polymer

SAN resins are rigid, hard, transparent thermoplastics which process easily and have good dimensional stability—a combination of properties unique in transparent polymers. 

Materials. For holographic information storage, materials are required which alter their index of refraction locally by spotwise illumination with light. Suitable are photorefractive inorganic crystals, eg, LiNbO, BaTiO, LiTaO, and Bq2 i02Q. Also suitable are photorefractive ferroelectric polymers like poly(vinyhdene fluoride-i o-trifluorethylene) (PVDF/TFE). Preferably transparent polymers are used which contain approximately 10% of monomeric material (so-called photopolymers, photothermoplasts). These polymers additionally contain different initiators, photoinitiators, and photosensitizers. 

If dye molecules are embedded into an amorphous matrix, preferably transparent polymers, greatly and inbornogenously broadened spectral lines are observed. This broadening is caused by the energetic interaction of the dye molecules with the locally different environment in the polymer matrix. The ratio of the homogenous initial line width of the dye molecule T to the inhomogenous line width of the dye in the polymer T ranges from 1 10 to 1 10 . ... 

The semicrystalline, ethylene-based ionomers of commerce are flexible, transparent polymers notable for high strength and elasticity in both soUd and molten states. The ionic bonding is completely reversible (8) and has a strong influence on properties, even at temperatures well above the melting point. 

Commercially available photon tunneling microscopes have a lateral resolution of 160 nm but subnanometer vertical resolution. The nondestmctive, instantaneous 3-D viewing of a surface (no scanning) yields real-time imaging as one traverses a given sample. The sample must be a dielectric, but transparent polymer tepHcas of opaque samples can be studied. 

Acryloid and Plexigum. These were soft gummy products of interest as surface coatings rather than as mouldable plastics materials. About 1930 R. Hill in England and W. Bauer in Germany independently prepared poly(methyl methacrylate) and found it to be a rigid, transparent polymer, potentially useful as an aircraft glazing material. ... 

The commercial success of ABS polymers has led to the investigation of many other polyblend materials. In some cases properties are exhibited which are superior to those of ABS and some of the materials are commercially available. For example, the opacity of ABS has led to the development of blends in which the glassy phase is modified to give transparent polymers whilst the limited light aging has been countered by the use of rubbers other than polybutadiene. 

To a chemist, a polymer is described by its chemical structure. To a manufacturer or a consumer, the important features of a polymer are its macroscopic properties. A tire manufacturer needs a flexible, tough, and durable polymer. A shirtmaker wants to spin a polymer into fibers that wear well, hold dyes, and are free of wrinkles. Makers of lenses look for transparent polymers that can be molded into precise shapes. Each of these polymer applications has somewhat different requirements. 

Photon Antibunching Behavior of Organic Dye Nanocrystals on a Transparent Polymer Film 217... 

The PEM (proton exchange membrane) material is a perfluorosulfonic acid polymer film. Several manufacturers make PEMs in one form or another. We used one made by du Pont called Nation 117. Nation 117 is a transparent polymer film about 175 microns (0.007 inches) thick. Dow Chemical Co., Asahi Chemical Co., and Chloride Engineers Ltd. make something similar. A patent describing how one PEM manufacturer s film is processed is listed in the references section at the end of this article. 

Ganzler, K., Greve, K. S., Cohen, A. S., Karger, B. L., Guttman, A., and Cooke, N. C., High-performance capillary electrophoresis of SDS-protein complexes using UV-transparent polymer networks, Anal. Chem., 64, 2665, 1992. 

Turbidimetry is ideally suited to detect the temperature at which a transparent polymer solution turns opaque. The temperature corresponding to the onset of the increase of the scattered light intensity is usually taken as the cloud-point temperature, TcP, although some authors define the cloud point as the temperature for which the transmittance is 80% (or 90%) of the initial value. This technique is commonly known as the cloud-point method [199]. Turbidimetry was employed, for instance, to show that the cloud-point temperature of aqueous PNIPAM solutions does not depend significantly on the molar mass of the polymer [150]. 

Room-temperature phosphorescence (RTP), dispersing the compound under investigation in a transparent polymer matrix such as Perspex... 

Polymerization of monomers in the absence of any other solvent is called bulk polymerization. Bulk polymerization of monomers, such as hydrox-yethyl methacrylate (or HEMA), leads to the production of a glassy, transparent polymer matrix that is very hard. When immersed in water, such a glassy matrix swells to become relatively soft and flexible. Although it allows the transfer of water and some low molecular weight solutes, this kind of swollen polymer matrix (i.e., hydrogel) is considered nonporous. The... 

Bisphenol-A (BPA) or 2,2-bis(4-hydroxyphenyl)propane is one of the highest volume chemicals produced worldwide, with a production volume of approximately 3.8 million tons in 2006 [199]. BPA is mainly used as monomer in the production of polycarbonate and epoxy resins. Polycarbonate is a transparent polymer with a high impact resistance which can be used in different consumer goods such as reusable drinking bottles and food containers. Epoxy resins on the other hand are used as inner coating of food and drink cans. Release and exposure of... 

Photographic emulsions. These are very commonly used, the silver halide emulsions are coated on glass or transparent polymer film. The emulsions, which involve the use of ultrafine grain size silver halide, are available for response to a range of laser wavelengths. This is the mainstay method in graphics art outlets. 

Clawson, J. M. (2007). Feasibility of a Mars surface inflatable greenhouse Availability of photosynthetic irradi-ance and durability of transparent polymer films. Dissertation, University of Colorado, Aerospace Engineering Dept.(191 pages). 

Stress on optically transparent polymers below the Tg may cause stretching of the fixed covalent bonds and distortion of the bond angles in the polymer chain. The behavior of the elastic solid below the Tg will approach Hooke s law for short strain or elongation, but covalent bonds will break if sufficient stress is applied. 

The opacity of plastic foams, and polymers with scratched surfaces, is also governed by Fresnel s law. The n value of the gas which occupies the scratch indentation is much lower than that of the polymer. Light may be directed through rods of transparent polymers, such as PMMA. This effect may be enhanced when the rod or filament is coated with a polymer with a different refractive index, such as polytetrafluoroethylene (ptfe). Optical fibers utilize this principle. 

Furthermore, the number of hydrogen atoms in a unit volume of 6FDA/TFDB is much smaller than for transparent polymers PMMA, PS, and PC, and these hydrogen atoms are only bonded to benzene rings. 

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