Polymer color analysis by transmission spectrophotometry using high refractive index composite liquids
AssigneesNorth Carolina State University, Eastman Chemical Company
InventorsOrlin D. Velev, Lokendra Pal, Sachin Agate, Austin Williams, Joseph Dougherty
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Abstract
The present invention provides a method for directly measuring the color of transparent polymer particles. A composite liquid, comprising a transparent liquid with nanoparticles and matching the refractive index of the polymer, can be used to mitigate the light scattering due to the roughness of the particles surface. The method can be applied to copolyester particles, such as copolyester pellets.
Claims20
A process for directly measuring the color of polymer particles, the process comprising:
- a) obtaining polymer particles;
- b) obtaining a composite fluid comprising a transparent liquid and nanoparticles;
- c) preparing a sample by combining a first fraction of the polymer particles with the composite fluid;
- and
- d) performing transmission spectrophotometry to determine a color of the sample,
- wherein the polymer particles are transparent,
- wherein the transparent liquid is inert to the polymer particles;
- and
- wherein an absolute difference between the refractive index of the polymer particles and the refractive index of the composite fluid (ΔRI) is less than 0.02.
A process for directly measuring the color of copolyester particles, the process comprising:
- a) obtaining copolyester particles;
- b) obtaining a composite fluid comprising a transparent liquid and nanoparticles;
- c) preparing a sample by combining a first fraction of the copolyester particles with the composite fluid;
- and
- d) performing transmission spectrophotometry to determine a color of the sample,
- wherein the transparent liquid is inert to the copolyester particles,
- wherein the nanoparticles comprise zirconia and/or titania, and
- wherein the absolute difference between the refractive index of the copolyester particles and the refractive index of the composite fluid (ΔRI) is less than 0.02.
Dependencies are inferred from the claim text.