Transparency and high heat resistance of cardo based poly(arylene ether)s for flexible plastic substrates

Abstract

New poly(arylene ether)s (PAEs) with both transparency and heat-resistance were prepared by the polycondensation of 4-fluoro-4'(((fluorobenzoyl)phenyl)-oxy)diphenyl sulfone), an ordered-sequence aromatic dihalide, and cardo typed aromatic diols that contain fluorene, adamantane, or cyclohexane moiety. The resulting polymers were found to be amorphous by X-ray diffraction, and their glass transition temperatures ranged from 194 to 245 o C. Based on the TGA data, they exhibited excellent thermal stability, showing 5% weight loss at 444-496 o C. They had low thermal expansion coefficients of 58-74 ppm at the temperature range of 50-200 o C as well as good mechanical properties with moduli of 1,785-2,350 MPa, except for the PAE that contains the cyclohexane moiety (86 ppm at 50-160 o C; 1,070 MPa). The optical transmittance of the PAE films (ca. 40 µm thick) was more than 70% at 450-800 nm and they also exhibited a very high refractive index in the range of 1.714-1.752 at 589 nm. In addition, their films showed a low water uptake of approximately 0.65% regardless of their chemical composition. Therefore, the newly developed PAEs show strong potential as plastic substrates for flexible devices for displays, solar cells and e-paper.

Synthesis of Cardo Based Poly(arylene ether)s for Flexible Plastic Substrates and Their Properties

“…The modulus of PAE-1 containing cage typed adamantane group (2,2-BHPA) was 1964 MPa, which is close to that of Appear R (1900 MPa), which contains similar cage typed norbornane moiety. The modulus of PAE-2 and -3, a random copolymer of PAE-1 and poly-(BHPF/FDPODS) with the modulus of 2350 MPa, 15 are fairly proportional to the composition ratio of each polymer. However, PAE-4 with naphthalene group had the lowest modulus value.…”

“…This is likely due to the fact that the compact adamantane groups of 70 mol % occupy the vacant space (so-called free volume) resulting from the bulky fluorene groups located perpendicular to the polymer main chain, and these results are in agreement with our earlier research. 15 However, as the content of BHPF introduced in the polymer chain raised from 30% (PAE-3) to 70% (PAE-2), CTE value is inferior from 58.0 to 58.7 ppm. Additionally, PAE-4, which contains 30% of naphthalene groups, exhibited the lowest CTE (57.9 ppm).…”

“…15 Furthermore, it is very interesting that PAE-3 exhibited somewhat lower CTE (58.0 ppm) than PAE-1, even though 30 mol % of bulky fluorene group was introduced into the PAE-1. This is likely due to the fact that the compact adamantane groups of 70 mol % occupy the vacant space (so-called free volume) resulting from the bulky fluorene groups located perpendicular to the polymer main chain, and these results are in agreement with our earlier research.…”

Effects of Bi2Se3 Amount in Thermoelectric Performance of Bi2(TeSe)3 Materials Fabricated by High‐Energy Ball Milling

“…3,12 Since last decade, powder metallurgy methods such as gas atomization, grinding, and ball milling followed by hot pressing, extrusion, hot deformation, and spark plasma sintering(SPS) have shown promising results to manufacture Bi 2 (TeSe) 3 materials with higher strengths and comparable TE properties. [13][14][15] Mechanical alloying by high-energy ball milling (HEBM) of pulverized elements is a successful alloy powder processing technique. Fine microstructure, solid state alloying, and the presence of desired defects in alloy powder have allowed researcher to manipulate the ball-milling operation to develop high-performance TE materials.…”

“…Generally, zone melting, Bridgman and Czochralsky techniques are used for fabrication of Bi 2 (TeSe) 3 materials, but practical applications of thus manufactured materials are limited due to their lower mechanical strength . Since last decade, powder metallurgy methods such as gas atomization, grinding, and ball milling followed by hot pressing, extrusion, hot deformation, and spark plasma sintering(SPS) have shown promising results to manufacture Bi 2 (TeSe) 3 materials with higher strengths and comparable TE properties . Mechanical alloying by high‐energy ball milling (HEBM) of pulverized elements is a successful alloy powder processing technique.…”