High refractive index polymers have been widely developed in recent years for their potential applications in advanced optoelectronic fabrications, such as high performance components for advanced display devices, encapsulants for light-emitting diode devices, microlens components for complementary metal oxide semiconductor image sensors, plastic lenses for eyeglasses, and camera, pick-up, and projector lenses. This Perspective describes the recent progress in high refractive index (n) polymers over the past decade and focuses on the design concept to increase n values and Abbe’s number (ν) of polymers. After a brief introduction of the basic methodology for developing high-n polymers and important parameters, such as Abbe’s number and birefringence, applications of high-n polymers, such as antirefractive coatings, microlenses for CMOS image sensors, encapsulants for LEDs, and high-n thermoplastic lenses, are highlighted.

Recent Progress in High Refractive Index Polymers

Electrospun polyimide nanofibers and their applications

Polymerizations with elemental sulfur: A novel route to high sulfur content polymers for sustainability, energy and defense

Polyimide aerogels combine high porosity, low thermal conductivity, flexibility, and low density with excellent mechanical properties. However, previously used cross-linkers, such as 1,3,5-triaminophenoxybenzene (TAB), 2,4,6-tris(4-aminophenyl)pyridine (TAPP), or octa(aminophenoxy)silsesquioxane (OAPS), either are not commercially available or are prohibitively expensive. Finding more cost efficient cross-linkers that are commercially available to synthesize these aerogels is crucial for making large scale manufacturing attractive. Herein, we describe an approach to making polyimide aerogels starting with amine capped oligomers that are cross-linked with 1,3,5-benzenetricarbonyl trichloride (BTC). BTC is a lower cost, commercially available alternative to TAB, TAPP, or OAPS. Aerogels made in this way have the same or higher modulus and higher surface area compared to those previously reported with either TAB or OAPS cross-links at the same density. While the cross-link structure is an amide, the thermal s...

http://pubs.acs.org/doi/pdf/10.1021/am507268c

Polyimide aerogels with amide cross-links: A low cost alternative for mechanically strong polymer aerogels

Polyimides containing aliphatic/alicyclic segments in the main chains

Synthesis and characterization of highly optical transparent and low dielectric constant fluorinated polyimides

Polyimide (PI) aerogels containing rigid-rod biphenyl, benzimidazole, and triphenylpyridine moieties have been developed. The flexible PI aerogels exhibited excellent thermal stability with glass-t...

Highly Thermally Resistant and Flexible Polyimide Aerogels Containing Rigid-rod Biphenyl, Benzimidazole, and Triphenylpyridine Moieties: Synthesis and Characterization

Novel polyfluorinated polyimides derived from α,α-bis(4-amino-3,5-difluorophenyl)phenylmethane and aromatic dianhydrides: Synthesis and characterization

Two fluorinated aromatic bis(o-aminophenol)s, 1,1-bis(3′-amino-4′-hydroxyphenyl)-1-(3′-trifluoromethylphenyl)-2,2,2-trifluoroethane (6FAP) and 1,1-bis(3′-amino-4′-hydroxyphenyl)-1-(3′,5′-ditrifluoromethylphenyl)-2,2,2-trifluoroethane (9FAP) were synthesized, which were allowed to polycondense with aromatic diacyl chlorides to afford the fluorinated aromatic polybenzoxazoles (PBOs) via a conventional two-step procedure in which the low-temperature solution polycondensation process was first performed to yield poly(o-hydroxyamide)s (PHAs) followed by the thermal cyclodehydration to give the PBOs. Experimental results indicated that the PHAs had inherent viscosities in the range of 0.29–0.68 dL/g, showing excellent solubility in organic solvents. The PHAs could be thermally cyclodehydrated into the corresponding PBOs at 260–370 °C. The obtained PBOs exhibited enhanced glass-transition temperature but decreased solubility with respect to the PHAs. The PBOs showed glass-transition temperatures in the range of 315–337 °C and excellent thermal stabilities with 5% original weight-loss temperatures (T5) of >513 °C. Additionally, the PBO films had average refractive index of 1.5298–1.5656, birefringence of 0.0051–0.0092, and low dielectric constants of 2.57–2.70. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

Synthesis of fluorinated polybenzoxazoles with low dielectric constants

Two fluorinated aromatic bis(o-aminophenol)s, 1,1-bis(3′-amino-4′-hydroxyphenyl)-1-(3′-trifluoromethylphenyl)-2,2,2-trifluoroethane (6FAP) and 1,1-bis(3′-amino-4′-hydroxyphenyl)-1-(3′,5′-ditrifluoromethylphenyl)-2,2,2-trifluoroethane (9FAP) were synthesized, which were allowed to polycondense with aromatic diacyl chlorides to afford the fluorinated aromatic polybenzoxazoles (PBOs) via a conventional two-step procedure in which the low-temperature solution polycondensation process was first performed to yield poly(o-hydroxyamide)s (PHAs) followed by the thermal cyclodehydration to give the PBOs. Experimental results indicated that the PHAs had inherent viscosities in the range of 0.29-0.68 dL/g, showing excellent solubility in organic solvents. The PHAs could be thermally cyclodehydrated into the corresponding PBOs at 260-370 °C. The obtained PBOs exhibited enhanced glass-transition temperature but decreased solubility with respect to the PHAs. The PBOs showed glass-transition temperatures in the range of 315-337 °C and excellent thermal stabilities with 5% original weight-loss temperatures (T₅) of >513 °C. Additionally, the PBO films had average refractive index of 1.5298-1.5656, birefringence of 0.0051-0.0092, and low dielectric constants of 2.57-2.70.

Haixia Yang

Papers

Synthesis and characterization of highly optical transparent and low dielectric constant fluorinated polyimides

Highly Thermally Resistant and Flexible Polyimide Aerogels Containing Rigid-rod Biphenyl, Benzimidazole, and Triphenylpyridine Moieties: Synthesis and Characterization

Novel polyfluorinated polyimides derived from α,α-bis(4-amino-3,5-difluorophenyl)phenylmethane and aromatic dianhydrides: Synthesis and characterization

Synthesis of fluorinated polybenzoxazoles with low dielectric constants

Synthesis of fluorinated polybenzoxazoles with low dielectric constants Part A Polymer chemistry