Synthesis of soluble and autophotosensitive hyperbranched polyimides with good optical properties and thermal properties

Abstract

A series of autophotosensitive hyperbranched polyimides based on a new triamine, 1,3,5-tri(3-aminophenoxy-4 0-benzoyl) benzene (TABB), various aromatic dianhydride monomers, and endcapped with ortho-alkyl aniline was synthesized by two-step chemical imidization methods. UV-vis spectra indicated high optical transparency of the hyperbranched polymer (HBPI) films with a UV-vis absorption edge of 342-353 nm. The spin-coated films of HBPIs presented a minimum birefringence value as low as 0.0026 at 650 nm and low dielectric constants of 2.74-3.09 (at 1 MHz). The HBPI films also showed high glass-transition temperatures between 190 and 238 1C, good thermal stabilities with 5 wt % loss temperatures ranged from 506 to 525 1C and excellent organosolubilities even in acetone and chloroform. Photolithographic property of the polymer was examined by UV exposure. SEM analysis revealed that highly resolved pattern with a line width of 20 lm were obtained.

Synthesis of new autophotosensitive semiaromatic hyperbranched polyimides with excellent mechanical properties and low birefringences

“…The method of synthesizing (A 2 + B 3 )-type hyperbranched PI has been described in detail on the basis of the preceding work. 12 The synthesis route was similar to the conventional two-step method for the synthesis of linear PI. The first-step polycondensation of excess BPADA with MSDS afforded PAAs, and the composition of three kinds of the molar ratio between BPADA and MSDS was 2:1, 4:3, and 8:7, respectively.…”

“…N , N -Dimethylformamide, N , N -dimethylacetamide (DMAc), and acetone were purified by distillation under reduced pressure over calcium hydride and stored over 4 Å molecular sieves. TABB was synthesized in the literature according to the method described by Liu et al 12…”

“…In addition, the high functionality of the peripheral PS groups is expected to produce high sensitivity toward exposure. 12 It is noteworthy that the charge transfer occurs in usual aromatic PIs, because aromatic imide groups and phenylene groups are electron acceptive and electron donative, respectively. 13,14 It may also be a reason for low quantum yields of PS benzophenone(BP)-based PIs with ethyl-substituted aromatic diamines.…”

“…16 Meanwhile, the semiaromatic PIs could be better candidates for optical and low dielectric materials owing to their lower dielectric constants, better colorless transparency, and almost the same T g s compared with conventional fully aromatic PIs. 8,17,18 Liu et al 12 reported a series of soluble auto-PHBPIs with a new triamine 1,3,5-tri(3-aminophenoxy-4′-benzoyl) benzene (TABB). 4,4′-(Hexafluoroisopropylidene)-diphthalic anhydride, benzophenonetetracarboxylic dianhydride, and 4,4′-(4,4′-isopropylidenediphenoxy)-bis(phthalic anhydride) as dianhydrides.…”

Solvent‐resistant ultrafine nonwoven fibrous membranes by ultraviolet‐assisted electrospinning of organo‐soluble photosensitive polyimide resin

“…In addition, owing to the self-sensitivity of this PSPI, its shrinkage and weight loss were much reduced in the absence of extra photosensitizers, which made it perform as an appropriate candidate for ES. 37,38 The PSPI showed as a negative mechanism whose exposed area experienced photo induced crosslinking then became insoluble in organic solvents. [39][40][41] The synthesis of the PI resin and the morphology of the fibers were studied.…”