Synthesis and characterization of ternary-copolymer of soluble fluorinated polyimides based on 1,4-bis (4-amino-2-trifluoromethylphenoxy) benzene

Structure–property relationship of polyetherimide based on aromatic dianhydride and long alkyl chain containing aromatic diamines

A series of new poly(ether imide)s (PEIs) were synthesized from different commercially available dianhydrides like 3,3′,4,4′-benzophenonetetracarboxylic dianyhride (BTDA) and pyromellitic dianhydride (PMDA) and diamines like 1,4-bis(4-aminophenoxy)propane, 1,4-bis(4-aminophenoxy)butane, 1,4-bis(4-aminophenoxy)pentane, and 1,4-bis(4-aminophenoxy)hexane by a typical two-step polymerization method. The structure of the monomers and PEIs prepared were confirmed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance and carbon-13 nuclear magnetic resonance spectral analysis. Solubility of the PEIs was tested in various organic solvents. Thermal properties of the PEIs were investigated by thermogravimetric analysis and differential scanning calorimetry. The temperature corresponding to 5% ( T5%) and 10% ( T10%) weight loss are from 318°C to 418°C and from 380°C to 480°C, respectively. These PEIs exhibit glass transition temperature in the range of 195–245°C, very low water absorption (0.37–0.62%), and low dielectric constant (2.68–3.17) at 1 MHz. The PEIs film possessed good mechanical properties with tensile strength of 77–98 MPa, elongation at break of 8–13%, and tensile modulus of 1.5–2.2 GPa. These results imply that the synthesized PEIs are well suited to be used as dielectric materials. Based on these studies the structure–property relationships were established.

Synthesis and characterization of novel fluorosilicone polyimides with high optical transparency

To overcome insoluble and low transmittance of the traditional polyimides (PIs), two kinds of novel fluorosilicone PIs were prepared. First, 1,4-bis (4-amino-2-trifluoromethylphenoxy) benzene, compound 3a, and 4,4′-bis(4-amino-2-trifluoromethylphenoxy)diphenyl ether, compound (3b), with 2-chloro-5-nitrobenzotrifluoride and p-hydroquinone or 4,4′-dihydroxydiphenyl ether were prepared. Second, hydrosilylation of nadic anhydride (NA) with 1,1,3,3-tetramethyldisiloxane (TMDS) yielded 5,5′-(1,1,3,3-tetramethyl-1,3-disiloxanediyl) bisnorbornane-2,3-dicarboxylic anhydride, compound (4). Initially, the conditions of the synthesis reaction such as reaction temperature, catalyst dosage, molar ratio of TMDS/NA, and reaction time on yield of compound 4 by the single factor approach were studied. The optimal reaction conditions were reaction temperature: 90°C, catalyst dosage: 1 ml (Pt% = 0.37%), molar ratio of TMDS/NA: 1/1.8, and reaction time: 3 h. The yield was 74.6%. Finally, two kinds of new organosoluble, light-colored, and good thermal stable fluorosilicone PI compounds (5a-5b) were synthesized from compounds 3a-3b and 4 and 4,4′-hexafluoroisopropylidenediphthalic anhydride), prepared through a typical two-step polymerization method. The solubility of the novel fluorosilicone PI films of compounds 5a-5b and the traditional PI film (4,4′-diaminodiphenyl ether (ODA)-biphenyltetracarboxylic dianhydride, DIY) were contrasted. The result showed that the fluorosilicone PI films have good solubility. These PIs were soluble in amide polar solvents and even in less polar solvents. The glass transition temperatures of compounds 5a-5b were 229.1 and 186.7°C and the 5% and 10% weight-loss temperatures were 519.8°C and 539°C, respectively. These films had cutoff wavelengths of 331.8 and 318.6 nm. Due to these properties, these PIs could be used as aerospace, photoelectric, and microelectronic materials.