Synthesis and Characterization of Some Functional Polyimides

Insights on Light Dispersion in Semi‐Alicyclic Polyimide Alignment Layers to Reduce Optical Losses in Display Devices

“…These two features ensure the premises to achieve high free volume and low polarizability, which improve the optical properties of the resulting material. Previous works revealed that the PIs prepared from this reagent and other aromatic diamines exhibit high thermal resistance ( T g > 220 °C), hydrophobic and smooth surface, high transparency (>80%) in the visible range, and low dielectric constant (<3). Besides the bulk properties of such PIs, a proper adaptation of the surface features must be made to ensure the desired uniform alignment of the NLC molecules .…”

Influence of two structural phases of Fe3O4and γ-Fe2O3on the properties of polyimide/iron oxide composites

“…In the first reaction step, performed at 15–20 °C, the corresponding PAA (Scheme ) is obtained. The details of synthesis are reported elsewhere …”

Synthesis of Highly Thermostable and Transparent Colorless Polyimides Based on a Semi‐aromatic Tetracarboxylic Anhydride

“…Another effective way to transparent PIs is to use monomers containing nonconjugated spacer such as diphenylether diamine [12] or triphenylmethylene diamine. [13] One of the most promising approach is to synthesize semi-aromatic PIs consisting of aromatic diamines and alicyclic dianhydrides, such as 1,2,3,4butanetetracarboxylic dianhydride (BT), [14] 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), [15] 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride (DM-CBDA), [16] 1,2,3,4-cyclopentanetetracarboxylic dianhydride (CPDA), [17] 1S,2R,4S,5Rcyclohexanetetracarboxylic dianhydride (CHDA), [4,18] bicyclo-[2.2.2]oct-7-ene-2-exo,3-exo,5-exo,6-exo-2,3 : 5,6-dianhydride (BTA), [19] bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic 2,3 : 5,6-dianhydrides (H-BTA), [20] 3,3',4,4'-bicyclohexyltetracarboxylic dianhydride (H-BPDA), [21] 5-(2,5-Dioxytetrahydrofuryl)-3-methyl-3cyclohexene-1,2-dicarboxylic anhydride (CDA), [22,23] cyclopentanone bis-spironorbornanetetra carboxylic dianhydride (CpODA) [24] and 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride (TDA) [25] as show in Scheme 1. [4,18,26,27] Although these semi-aromatic PIs always have high optical transparency, good solubility and low CTE, they still suffer from the relatively low thermal stability.…”