Synthesis and characterization of soluble polyimides based on trifluoromethylated aromatic dianhydride and substitutional diaminetriphenylmethanes

Synthesis and properties of new pyridine-bridged poly(ether-imide)s based on 4-(4-trifluoromethylphenyl)-2,6-bis[4-(4-aminophenoxy)phenyl]pyridine

“…This can be explained that introduction of the strong electron negativity of -CF 3 groups might enhanced the polarity of the polymer, which should restrict the movement of polymer-link and lead better thermal stability [34]. Table 3 Thermal properties of the poly(ether-imide) films, and their comparison with previously reported polyimides [28,29] Polymer Thermal properties According to the data presented in Table 3, these poly(etherimide) films showed higher onset decomposition temperatures, 5% and 10% weight loss temperatures, and char residues than many fluorinated poly(ether-imide)s [14][15][16][17]35]. This should be resulted from the introduction of pyridine ring into the polymer backbone, whose rigidity based on its symmetry and aromaticity should have contributions to the polymer thermal stability [20,21].…”

“…In order to overcome these limitations, soluble polyimides have been targeted by many efforts, including introduction of flexible linkages [4][5][6], bulky units [7,8], bulky pendent substituents [9][10][11], or non-coplanar moieties [12,13], in the polymer backbone. Recently, considerable attention has been devoted to the fluorinated aromatic poly(ether-imide)s, especially trifluoromethyl-containing poly(ether-imide)s, with excellent solubility and low refractive indices, water uptake, and dielectric constant [14][15][16][17]. It was found that the incorporation of bulky -CF 3 into poly(etherimide) backbones resulted in an enhanced solubility and optical transparency together with a lowered dielectric constant, which attributed to low polarizability of the C-F bond and the increase in free volume.…”

Synthesis and characterization of fluorinated polyimides derived from novel unsymmetrical diamines

“…Thus, many studies have focused on designing such chemical structures of the rigid aromatic backbone so as to obtain aromatic polymers that are processable by conventional techniques, while maintaining desirable properties. For example, bulky lateral substituents [3][4][5], flexible linkages [6][7][8], noncoplanar biphenyl moieties [9,10] as well as unsymmetrical structures [11][12][13] have been used to enhance the solubility of aromatic polymers make them processability.…”

“…As well known, introduction of geometrically or molecularly unsymmetrical diamine components into the polyimide main chain has led to new polyimides with improved solubility, melt processability and other desirable properties [14][15][16][17][18][19]; additionally, fluorination is also known for increasing intermolecule space while enhancing the solubility, optical transparency and lower moisture absorption of polyimides [6,20,21].…”

Preparation of Oriented Aluminum Nitride Thin Films on Polyimide Films and Piezoelectric Response with High Thermal Stability and Flexibility

“…Polyimide films were chosen as substrates because they exhibit high thermal stability (working temperature: -269 to 400°C), chemical resistance, and good mechanical properties. [18] In this paper, we report the crystal state and piezoelectric responses of AlN films prepared on polyimide films using a radio frequency (rf) magnetron reactive sputtering technique. The AlN films exhibit crystal orientation and high thermal stability.…”