Synthesis and characterization of high refractive index polyimides derived from 2,5-Bis (4-Aminophenylenesulfanyl)-3,4-Ethylenedithiothiophene and aromatic dianhydrides

Abstract

The authors describe the synthesis and characterization of the polyimide (PI) series containing a 2,5-bis(4-aminophenylenesulfanyl)-3,4-ethylenedithiothiophene (APSEDTT) moiety in their main chain. The APSEDTT monomer with high sulfur content was prepared and polymerized with several aromatic dianhydrides such as 4,4 0 -[p-thio bis(phenylenesulfanyl)]diphthalic anhydride (3SDEA), 4,4 0 -biphthalic anhydride (BPDA), and 4,4 0 -oxydiphthalic anhydride (ODPA) by the traditional two-step polycondensation procedure. All PIs exhibited high transparency, higher than 75% at 550 nm for a thickness of about 20 lm and good thermal properties such as thermal decomposition temperatures (T 10% ) in the range of 409-521 C. In addition, the PIs have extraordinarily excellent optical properties in refractive index and birefringence as originally designed. In particular, the PI derived from APSEDTT and 3SDEA showed a high refractive index (1.7586), and a low birefringence (0.0087) because of their very high sulfur content (27.7%). V C 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 944-950

Synthesis and characterization of highly-fluorinated colorless polyimides derived from 4,4′-((perfluoro-[1,1′-biphenyl]-4,4′-diyl)bis(oxy))bis(2,6-dimethylaniline) and aromatic dianhydrides

“…The inplane (n xy ), out-of-plane (n z ), average refractive indices (n av ), inplane/out-of-plane birefringences (Dn), refractive indices at the infinite wavelength (n ∞ ), and dispersion coefficients of refractive index (D) of the PI films (thickness < 10 mm) are summarized in Table 3. The refractive indices of the PIs are in the range of 1.5389e1.6168 measured at 637 nm and those values are significantly lower than that of a conventional PI, such as Kapton [PMDA-ODA] and Upilex-S [BPDA-PDA] [33]. In addition, the n av of the PIs at 637 nm are in the order of 6FDA < PMDA < ODPA < BPDA < PMDA′, which tended to match the high order of fluorine content except for PMDA′.…”

“…Polyimide films were fabricated by the typical two-step thermal imidization procedure (Scheme 2) [33]. First, the PAA precursors were synthesized by polymerization with diamine, 8FBPOA or 8FBPODMA, and dianhydride monomers such as 6FDA, PMDA, BPDA, ODPA in NMP as shown in Scheme 2.…”

Fast Curable Polysiloxane-Silphenylene Hybrimer with High Transparency and Refractive Index for Optical Applications

“…Thus, it is more effective to have a high refractive index to improve light transmission efficiency. To increase the refractive indices of polymers, the introduction of substituents exhibiting low molar volumes and high molar refraction such as halogen or sulfur atoms and aromatic rings is one of the promising approaches [ 3 ]. Although commercial epoxy resins exhibit good visible light transmission and protection against gas, they are susceptible to yellowing at high temperatures and exhibit low refractive indices [ 4 ].…”

Accelerated Discovery of High-Refractive-Index Polyimides via First-Principles Molecular Modeling, Virtual High-Throughput Screening, and Data Mining

“…In 2007, Ueda et al developed PI films with relatively high RI values of up to 1.75, but they, unfortunately, exhibited large birefringence [32]. In recent years, these findings have been improved upon by increasing the sulfur content of the PIs, yielding RI values of up to 1.76 and smaller birefringence [33].…”