Formation of honeycomb films based on a soluble polyimide synthesized from 2,2′‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride and 3,3′‐dimethyl‐4,4′‐diaminodiphenylmethane

Abstract

A soluble polyimide was synthesized from 2,2 0 -bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) and 3,3 0 -dimethyl-4,4 0 -diaminodiphenylmethane (DMMDA) by a two-step method, and it had good solubility both in strong bipolar solvents and in common lowboiling-point solvents. The BPADA-DMMDA polyimide was dissolved in chloroform (CHCl 3 ) and cast onto a glass substrate in a humid atmosphere. The BPADA-DMMDA/CHCl 3 solution easily formed honeycomb films. Some affecting factors, such as the polymer solution concentration, atmospheric humidity, and solvent volatility, were tested.

Low dielectric and thermally stable hybrid ternary composites of hyperbranched and linear polyimides with SiO2

“…Meanwhile, this low value can also be attributed to the other characteristics of monomers and polymers, i.e., the high uorine content from 6FDA, 30,31 the exible or kinked structures from APB, 32,33 and the bulky substituent structure from BPADA. [34][35][36] In addition to these effects, the introduction of inorganic silica can effectively reduce humidity absorption of the material and enhances the free volume. 28…”

Ternary composites of linear and hyperbranched polyimides with nanoscale silica for low dielectric constant, high transparency, and high thermal stability

“…The low dielectric constants of the system are also related with the fundamental characters of monomers, i.e., the high uorine content of 6FDA, 31,32 the exible and bent structure of APB, 33,34 and the bulky side groups of BPADA. [35][36][37] Moreover, the introduction of inorganic silica effectively reduces the moisture absorption of the material and expands the free volume. 29 The improved phase dispersion of HBPI BPADA-TAP(OH) and PI 6FDA-APB(Si) plays a very important role to result in the reduced dielectric constant in hybrid ternary composite lms.…”

“…25 The composite with the lowest D k (SF-4) in the series also shows a transmittance of 94% at 450 nm, which are also obviously higher than that of SA-4 (PI 6FDA-APB _HBPI BPADA-TAP(OH) -10%_SiO 2 -20%). 23 Fundamental characters of monomers, i.e., the high uorine content of 6FDA, 31,32 the exible and bent structure of APB, 33,34 and the bulky side groups of BPADA [35][36][37] are important for the colorless feature. On the other hand, this effect is also attributed to the synergy effect of HBPI BPADA-TAP(OH) and PI 6FDA-APB(Si) components to reduce the phase separation between PI matrices and silica particles, which improves the dispersibility and reduces the size of silica particles.…”

Interpretation of the mechanism of 3,3′-dichloro-4,4′-diamino diphenylmethane synthesis over HY zeolites

“…As a class of important chain-extending, cross-linking and curing agents, diaminodiphenylmethanes have been used extensively in the preparation of various polymer products including resin, rubber, plastic, paint, lm, etc. For example, 4,4 0 -diaminodiphenyl methane (MDA) is an important additive in the preparation of polyurethane and thermosets, 1-5 3,3 0dimethyl-4,4 0 -diamino diphenylmethane (MDT) is used as a good curing agent in the preparation of electric cables and wires with excellent properties of insulation, heat endurance and chemical resistance, [6][7][8][9][10] and also 3,3 0 -dichloro-4,4 0 -diaminodiphenylmethane (MOCA) plays a vital role in preparing high quality polyurethane and epoxy resin. [11][12][13][14] The condensation of unsubstituted and methyl-or chlorinesubstituted aromatic amine with formaldehyde (HCHO) has provided a convenient route to prepare MDA, 15,16 MDT 17 and MOCA.…”