$polymer refractive index database$

The set of 30 nanolayered polymer films exhibited transmission near 90% with each film varying in refractive index by 0.0017. A set of 30 polymer nanolayered films comprised of two thermoplastic polyurethanes having a refractive index difference of 0.05 were coextruded via forced-assembly technique. The two step illumination procedure provides the possibility of erasing and even inverting the index contrast generated during the first illumination step.Inspired by the soft, deformable human eye lens, a synthetic polymer gradient refractive index distribution (GRIN) lens with an adaptive geometry and focal power has been demonstrated via multilayer coextrusion and thermoforming of nanolayered elastomeric polymer films. Thus the final refractive index can be adjusted to values between n 589 = 1.564 to n 589 = 1.633. The reason for this behaviour seems to arise from the formation of different photoproducts depending on the irradiation sequence. When thin films of poly( 1- co- 2) already irradiated with 313 nm light are subjected to a second illumination step with 254 nm light, a significant decrease of the refractive index (Δ n 589 = −0.043) is observed. The copolymer poly( 1- co- 2) offers the possibilities of selectively exciting either the naphthyl ester with UV light of 313 nm causing an increase in the refractive index of Δ n 589 = 0.010, or both the naphthyl and phenyl chromophores with UV light of 254 nm (Δ n 589 = 0.036). The photoreaction causes an increase of the refractive index in poly- 2 between Δ n 589 = +0.022 and +0.048 depending on the irradiation wavelength.

$polymer refractive index database$

The photochemistry of these polymers under irradiation with UV light of either 254 nm or 313 nm was investigated. Poly(norbornene)-based polymers bearing naphthyl ester groups (poly- 2) and copolymers bearing both phenyl and naphthyl ester groups (poly( 1- co- 2)) were prepared by ring opening metathesis polymerization ( ROMP). In this contribution, we report on the synthesis of new photoreactive polymers bearing aryl esters which undergo the photo-Fries rearrangement to give aromatic hydroxyketones. Tuning and patterning of the refractive index in polymeric films is of importance for modern optical applications such as wave guiding and optical data storage.

$polymer refractive index database$

Polymer refractive index database