High Refractive Index Polyimides Derived from 2,7-Bis(4-aminophenylenesulfanyl)thianthrene and Aromatic Dianhydrides

Abstract

High refractive aromatic polyimides (PIs) containing a thianthrene-2,7-disulfanyl moiety in their main chain have been developed. The PIs were prepared from a newly developed aromatic diamine 2,7-bis(4-aminophenylenesulfanyl)thianthrene (APTT) and several aromatic dianhydrides by a two-step polycondensation procedure. The relationships between the structures and the thermal, mechanical, and optical properties of the flexible, tough, transparent, and amorphous PI films were established. Introduction of the thianthrene-2,7-disulfanyl group endowed the PIs with good combined properties, including high thermal stability with 10% weight loss temperatures (T 10%) higher than 500 °C in nitrogen and the glass transition temperatures (T gs) higher than 200 °C, good transparency with transmittances higher than 80% at 500 nm, and refractive indices higher than 1.73 at 632.8 nm. Because of higher sulfur content, the refractive indices of the PIs we synthesized are higher than those of PIs derived from the other sulfur-containing diamines such as 4,4‘-(p-phenylenedisulfanyl)dianiline (2SPDA) and 4,4‘-thiobis[(p-phenylenesulfanyl)aniline] (3SDA). The PI derived from APTT and 4,4‘-[p-thiobis(phenylenesulfanyl)]diphthalic anhydride (3SDEA) has the highest sulfur content (23.2%) in its repeating units, and hence, it exhibits the highest refractive index, i.e., 1.7600.

Physical, optical and gas transport properties of new processable polyimides and poly(amideimide)s obtained from 4,4′-[oxybis(4,1-phenylenethio)]dianiline and aromatic dianhydrides

“…In addition, absorption peaks at 740 cm À1 , which are attributed to imide ring deformation, were detected. Moreover, the strong peak at B1239 cm À1 and at B1082 cm À1 due to the presence of ether linkages (Ar-O-Ar) 4 and aromatic thioether linkages (Ar-SAr), 22 respectively, were observed. The lack of amide groups in the case of PI-III and PI-IV (without amide linkages) was confirmed by proton nuclear magnetic resonance spectroscopy.…”

“…[15][16][17] With regard to the PI microstructure, much effort is being devoted to the design and synthesis of PIs with thioether linkages. [18][19][20][21][22][23][24][25][26] One of the most popular research directions in sulfur-containing PI is the investigation of their use as high refractive index (n) materials. [27][28] High n polymers have been widely proposed for applications in advanced optoelectronic fabrication, such as high-performance components for advanced display devices, encapsulates for organic light-emitting diode devices, microlens component for charge-coupled devices, complementary metal oxide semiconductor image sensors, 20,21,25,28,29 antireflective coatings and for telecommunication systems as optical waveguide devices.…”

“…[18][19][20][21][22][23][24][25][26] One of the most popular research directions in sulfur-containing PI is the investigation of their use as high refractive index (n) materials. [27][28] High n polymers have been widely proposed for applications in advanced optoelectronic fabrication, such as high-performance components for advanced display devices, encapsulates for organic light-emitting diode devices, microlens component for charge-coupled devices, complementary metal oxide semiconductor image sensors, 20,21,25,28,29 antireflective coatings and for telecommunication systems as optical waveguide devices. 23 Moreover, such PIs are interesting for their potential applications as memory devices, 30 membranes for gas separation 18,19,31 and membranes for fuel cells.…”

“…32 Various sulfur-containing PIs have been recently developed. These polymers mainly consisted of diamine with thioether linkages in skeletal structures, such as 4,4¢-diaminodiphenyl sulfide, 33 oligo(phenylene thioether) diamines, 18,19 4,4¢-thiobis[(p-phenylenesulfanyl)aniline], 20,21 2,7-bis(4-aminophenylenesulfanyl)thianthrene, 21,22 2,2¢-bis-(trifluoromethyl)-4,4¢-diaminodiphenyl sulfide, 23 1,6-bis (p-aminophenylsulfanyl)-3,4,8,9-tetrahydro-2,5,7,10-tetrathiaantracene, 24 2,5-bis(4-aminophenylsulfanyl) tiophene, 2,5-bis{2¢-[5¢-(4 00 -aminophenyl) sulfanyl]thienyl} tiophene, 25 2,6-bis [4-(4-aminophenylsulfanyl) phenyl]-2-phenylpyridine, 4,4¢-(p-phenylenedisulfanyl)dianiline, 4,4¢-bis (p-aminophenylsulfanyl) biphenyl, 2,7-bis(4-aminophenylenesulfanyl) thianthrene and 4,4¢-sulfonylbis[(p-phenylenesulfanyl)aniline]. 26 In this paper, we report the synthesis of new PIs containing thioether linkages originating from 4,4¢-[oxybis(4,1-phenylenethio)]-dianiline.…”

Synthesis of Highly Refractive and Transparent Polyimides Derived from 4,4′-[p-Sulfonylbis(phenylenesulfanyl)]diphthalic Anhydride and Various Sulfur-containing Aromatic Diamines

“…8,9 Refractive indices as high as 1.76 at the wavelength of 632.8 nm, and in-plane/out-of-plane birefringences lower than 0.01 have been successfully achieved.…”