Synthesis and Properties of Polyimides from Aromatic Dianhydrides Having Various Number of Phenylene Units and Bis{4-[4-(4-aminophenoxy)phenoxy]phenyl}Ether

Abstract

A new para-substituted aromatic ether diamine, bis{4-[4-(4aminophenoxy)phenoxy]phenyl} ether 1, was synthesized in four steps starting from 4,4'-dibromodiphenyl ether. New aromatic polyimides, with 5 ether linkages per monomer unit, were prepared from this diamine and various tetracarboxylic dianhydrides, pyromellitic dianhydride (PMDA)

Synthesis and Properties of Polyimides from Bis[4-(Aminophenoxy)phenyl] Ether and Aromatic Dianhydrides Having Various Numbers of Phenylene Units

“…A high modulus glassy region was followed by a decrease in the modulus at T g . The E' value for amorphous PI-3e-PMDA decreased at around 350 °C to about 10 7 Pa, and the E' value at 400 °C was higher than that for PI-5e-PMDA due to fewer ether linkages [13].…”

“…3). The T g values for PI-3e-PMDA and PI-3e-0, PI-3e-1, PI-3e-2, PI-3e-3 and PI-3e-4 were 280 °C, 230 °C, 230 °C, 210 °C, 220 °C, and 210 °C, respectively (Table 1), which were slightly higher than those for PI-5e-PMDA and PI-5e-m (m = 0-4) [13], and the T g values were not dependent on m. The value for PI-3e-PMDA was the highest due to intermolecular charge transfer [19], similar to the case for previously reported polyimides from dianhydrides having various numbers of phenylene units [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

“…2 (a)). PI-3e-PMDA and PI-3e-m (m = 0-4) were insoluble in organic solvents even upon heating similar to PI-5e-PMDA and PI-5e-m (m = 0-4) [13].…”

“…We previously synthesized dianhydrides DA-m having various numbers (m) of phenylene units, DA-2 [1], DA-3 [2] and DA-4 [3]. These were used to prepare aromatic polyimides containing pquarterphenyl [1], p-quinquephenyl [2] and psexiphenyl [3] with various aromatic diamines [4][5][6][7][8][9][10][11][12][13]. The properties were compared with those of polyimides from DA-0 and DA-1, and discussed on the basis of the number (m) of phenylene units [14][15][16].…”

“…The decrease in modulus was smaller with increasing m. In polyimides from diamines with more ether linkage, unique DMA behavior was observed. The polyimides PI-5e-m (m = 0-4) from bis{4- [4-(4-aminophenoxy)phenoxy]phenyl} ether with 5 ether linkages showed a two-step decrease in the storage modulus at T g and the melting region, and exhibited adhesion when heated at the melting region [13]. The polyimides from DA-3 and 1,4-bis(4-amino-2-phenylphenoxy) benzene and 4,4'-bis(4-amino-2-phenylphenoxy) biphenyl having two ether linkages showed two rubbery plateau regions above the T g , and two tan  peak temperatures [9].…”