Refractive index epoxy resin

The curing of an epoxy resin adj acent to an embedded silica optical fibre was monitored in situ by evanescent wave spectroscopy. The epoxy resin was partially fluorinated and had a lower refractive index than the silica fibre. The lower refractive index of the epoxy resin allowed the silica optical fibre to be used as a waveguide for the internal reflection of the near-IR light. The epoxy resin curing was determined as a function of time and temp, by analysis of the near-IR spectmm from the epoxy adj acent to the fibre obtained by the interaction of the evanescent wave that occurred at each internal reflection with the low refractive index epoxy resin. The results obtained showed that epoxy ring-opening and... 

Properties often used by epoxy resin manufacturers to specify particular grades of resin include the epoxy content, viscosity or softening point, and color. In addition, properties such as density, vapor pressure, flash point, refractive index, solubility characteristics, and hydroxyl content are often reported. The important properties of uncured epoxy formulations with regard to most adhesive applications are... 

Refractive index is defined as the ratio of the speed of light of a given wavelength in vacuum to the speed of light at the same wavelength in the substance measured. The refractive index of epoxy resins is seldom reported. However, the property is important for cured epoxy adhesives that are used in the assembly of optical devices. 

FIGURE 28-28 Applications of size-exclusion chromatography, (a) Separation of fatty acids. Column polystyrene based, 7.5 x 600 nm, with exclusion limit of t x t0 Mobile phase telrahydrofuran. Flow rale 1.2 mL/min. Deteclor refractive index, (b) Analysis of a commercial epoxy resin n - number of monomeric units in the polymer). Column porous silica 6.2 > 250 mm. Mobile phase letrahydrofuran, Flow rate t.3 mL/min. Deteclor UV absorption. (Courtesy of BTR Separations.)... 

Microscopy. The polarized optical micrographs of thin films of HX-205 and F-185 neat resins were obtained using a Zeiss ultraphot microscope equipped with a polarizer and an analyzer. Thin films, approximately 100 microns thick, were prepared by thln-sectlonlng the resin sheet with a razor blade at room temperature. The domains were observable because of light scattering as a result of refractive Index mismatch between the rubber domain and the epoxy matrix, as well as to stress-induced birefringence produced by the thermal stress Imposed on the domains. 

We have devdoped a novd processable third-ordo NIO polymo , PSTF, in whidi tris-azo-dye NLO-phore was incorporated into die main chain of apdyurediane with a fluorinated alkyl badtb. Fluorinafed alkyl units were used to reduce the polymo wav uide loss. The dienncal structure of PSTF is shown in Figure 7. Since diiid-orda NLO polymers gmoally have hi ier refractive indioes thm transparent pofymos, the refractive imtet of die NLO polymers should be considmd. We can ply die RIE process for PSTF polymer because the polymer has a moderate refractive index and the cladding material, UV cored fluorinated epoxy resin, has an... 

This poled polymer was 3RDCVXY which exhibits a value of 80 pmA and a optical loss of 0.65 dB/cm in the form of a single-mode waveguide operating at 1.3 pm. AUV cured epoxy resin is also used as a core. The refractive index of the UV cured resin can be easily controlled(25). This controllability makes it easy to form a periodic laminar structure composed of poled polymer and UV cured resin with almost the same refractive index. On top of the silicon substrate, a low refractive index UV cured epoxy resin is spin coated as an under-cladding layer of the waveguide. Core... 

Methods making use of epoxy resins, resulting in polished sections in only a few minutes, are discussed first, followed by details of impregnation and encapsulation. Equipment and techniques for grinding and polishing, including thin-section procedures, are described. The use of Hyrax , a synthetic resin with an index of refraction of 1.70, is discussed, followed by a description of a recommended method for refractive-index determination of particles mounted on a thin film of epoxy. 

A representative sample of the coarse wet-sieved fraction (>125 pm) is mounted on a labeled, glass microscope slide with epoxy resin, having an index of refraction (n) of 1.55 to 1.56, or balsam fir resin n = 1.537) as described below, and the limestone particles are counted microscopically to determine their percentage. Counting techniques are given additional discussion later in this chapter. 

Mount the particles on a glass microscope slide with epoxy, refractive index liquids, or, if working with a thin section, put on the cover glass with epoxy resin (without hardener). 

With quickly setting epoxy resins or similar materials, such as cyanoacrylate ester (Super Glue ), and modern semiautomatic grinding and polishing equipment, polished sections can be made within a few minutes, while an alcohol-washed, sieved clinker powder, moimted in refractive-index oil, is studied. 

Alternatively, photosensitive epoxy SU-8 can be used as both the core and cladding layer. The refractive index of SU-8 can be reduced by mixing it with at least 2.7 % (by weight) liquid aliphatic epoxy resin DER 353TM from Dow Plastics [13]. The SU-8/aliphatic resin mixture was measured to have n=. 590 at 2 = 633 nm, as opposed to = 1.595 for the unmodified SU-8. The... 

Chloroform klor-9- form, kl6r- IF chloro-forme, fr. chlor- + formyle formyl fr. its having been regarded as a trichloride of this group] (1838) (trichloromethane) n. CHCI3. A pungent, toxic, dense liquid, useful as a solvent for epoxy resins and others. (2) Clean, colorless, volatile liquid. Sp gr of 1.485 (20/20°C) bp of 61.2°C fp of 63.5°C wt/gal of 12.29 lb (25°C) refractive index of 1.4422 See image). 

Impregnation. Porous samples and delicate materials should be impregnated. This is performed with the same media which will be used to cement the sample to the slide in a later step. The impregnating medium, consisting of epoxy resin or Canada balsam, should have a suitable index of refraction (close to 1.535), allowing the phases to be distinguished from one another by optical methods. In many cases, it is sufficient to simply lay the sample in the mounting medium and then allow capillary forces to... 

In recent years, epoxy resins have been nsed to realize optical disk matrices, lenses and prisms. However, the refractive index of conventional epoxy resins is low and their applications as optical materials where a high refractive index is reqnired are limited. For this reason, many efforts are being dedicated to synthesizing new optical epoxy resins characterized by a high refractive index, good mechanical properties and optimal thermal insulation. 

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