Mechanical properties of ladder-like polysilsesquioxane-based hard coating films containing different organic functional groups

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

“…On the other hand, EPSQ showed a broad peak in the range of −65 to −70 ppm, mostly from the T 3 structure. The ladder-type structure composed of the T 3 structure showed a strong intensity and a broad peak in the 29 Si NMR due to polycondensation [ 48 , 49 ]. As shown in Figure 1 c, various types of silicone bonds existed.…”

“…On the other hand, EPSQ had two Si–O–Si bonding peaks due to the unique double-stranded structure of the ladder-type structure [ 39 ]. The Si–O–Si symmetric stretching vibration of EPSQ occurred at 1020–1060 cm −1 , and asymmetric stretching vibration occurred at 1100–1150 cm −1 [ 7 , 33 , 48 ]. After the sol–gel reaction, the methoxy peak at 1080 cm −1 decreased, and two Si–O–Si chain peaks were observed at 1030 and 1100 cm −1 .…”

“…Unlike the EPOSS film, in the out-of-plane diffraction peak of the EPSQ film, broad diffraction peaks appeared at approximately 6.3 and 18.0°. The broad diffraction peak at 6.3° indicates the chain-to-chain length (d-spacing 1) of an interdigitated PSQ backbone by the side chain of EPSQ [ 48 ], and the d-spacing (d1) of the EPSQ film was 1.40 nm. On the other hand, the broad diffraction peak at 18.0° indicates the average thickness (d-spacing 2) of ladder-like polysilsesquioxanes [ 48 ].…”

Change of Characterization and Film Morphology Based on Acrylic Pressure Sensitive Adhesives by Hydrophilic Derivative Ratio

“…This is because the proportion of hydrogen bonding increased. As the hydrogen bonding became stronger because of the increase in HEA content, the distance between chains became closer because of the improved packing characteristic [ 47 , 48 , 49 , 50 ]. Moreover, because of the high ratio of the hard segment, the polymer chain also had a hard characteristic, making it possible to arrange the chain in a relatively ordered form.…”

“…Additionally, it was found that the modulus of acrylic PSA film increased in the high-temperature region of 100 °C with an increase in HEA. These results can be attributed to hydrogen bonding, which became stronger with the increased HEA [ 32 , 48 , 54 , 55 , 56 ]. Compared with the results for less than 10 wt % HEA, e.g., Acryl-2 to Acryl-8, the proportion of hydrogen bonding was very high by the flexible chain for Acryl-40, and all hydrogen bonds were not decomposed, even at temperatures in excess of 100 °C.…”