Hard Coating Materials Based on Photo-Reactive Silsesquioxane for Flexible Application: Improvement of Flexible and Hardness Properties by High Molecular Weight

Abstract

EPOSS of polyhedral oligomeric silsesquioxanes (POSS) mixture structure and LPSQ of ladder-like polysilsesquioxane (LPSQ) structure were synthesized via sol–gel reaction. EPSQ had a high molecular weight due to polycondensation by potassium carbonate. The EPSQ film showed uniform surface morphology due to regular double-stranded structure. In contrast, the EPOSS-coated film showed nonuniform surface morphology due to strong aggregation. Due to the aggregation, the EPOSS film had shorter d-spacing (d1) than the EPSQ film in XRD analysis. In pencil hardness and nanoindentation analysis, EPSQ film showed higher hardness than the EPOSS film due to regular double-stranded structure. In addition, in the in-folding (r = 0.5 mm) and out-folding (r = 5 mm) tests, the EPSQ film did not crack unlike the EPOSS coated film.

Photopatternable High‐kPolysilsesquioxane Dielectrics for Organic Integrated Devices: Effects of UV Curing on Chemical and Electrical Properties

“…The lower-angle peak (GLPSQ:2θ = 5.05° and d-spacing = 17.48 Å; CLPSQ:2θ = 5.96°, and d-spacing = 14.81 Å) appeared owing to the intramolecular periodic chain-to-chain distance, whereas the higher-angle peak (GLPSQ:2θ = 17.85° and d-spacing = 4.96 Å; CLPSQ:2θ = 18.45°, and d-spacing = 4.80 Å) appeared owing to the average thickness of the LPSQ (Figure 1d,e). [19][20][21] The lowerangle peak exhibited higher d-spacing for GLPSQ than that for CLPSQ, indicating that the glycidyl epoxy chain is longer than the cycloaliphatic epoxy chain (Figure 1d,e). The lower-angle XRD peaks observed in pristine GLPSQ and CLPSQ were not present in the UV-cured GLPSQ (GLPSQ + UVC) and CLPSQ (CLPSQ + UVC) thin films, indicating a random orientation of the bonds after the UV curing process (Figure 1d,e).…”

Self‐Healable and Stretchable PAAc/XG/Bi2Se0.3Te2.7 Hybrid Hydrogel Thermoelectric Materials

“…In the PAAc/XG matrix, the high molecular weight PAAc and XG have longer molecular chains, which are helpful for the flexibility of the material, making the material less prone to microcracks when it is bent, and ensuring the flexibility of PAAc/XG/Bi 2 Se 0.3 Te 2.7 . [ 32 ] The open‐circuit voltage and output power of PAAc/XG/Bi 2 Se 0.3 Te 2.7 (1.5 wt%) after bending are shown in Figure 4b. When the temperature difference is 40 K, the open‐circuit voltage is −17.5 mV and the output power is 38.0 nW, respectively.…”

“…In the PAAc/XG matrix, the high molecular weight PAAc and XG have longer molecular chains, which are helpful for the flexibility of the material, making the material less prone to microcracks when it is bent, and ensuring the flexibility of PAAc/XG/Bi 2 Se 0.3 Te 2.7 . [32] The open-circuit voltage and output power of PAAc/XG/Bi 4c-e. We used a razor blade to create a 1 mm-deep crack in the sample and placed it under an optical microscope to observe the crack healing process.…”

The Effect of Silane Acrylate Containing Ethylene Glycol Chains on the Adhesive Performance and Viscoelastic Behavior of Acrylic Pressure-Sensitive Adhesives for Flexible Displays

“…Due to these excellent properties, it is applied as a polymer material in various fields, from industrial films and point adhesives to surface coatings/hard coatings. Recently, silane/siloxane compounds have been studied for their application as functional hard coating materials applicable to flexible displays due to their high hardness and flexibility [12,13]. Consequently, the novel silane acrylate improved the cohesion and elasticity of the corresponding acrylic PSA, even with only 1 wt% addition, and showed high recovery characteristics and stress relaxation behavior, even at 400% deformation.…”