Effects of crosslinking agents on the physical properties of polyimide/amino‐functionalized graphene oxide hybrid films

Abstract

The effects of crosslinking agents (crosslinkers) on polyimide (PI)/graphene oxide (GO) hybrid films were extensively investigated. The surface of GO was modified with amino groups using 4‐aminobenzylamine to improve compatibility with pyromellitic dianhydride/4,4′‐oxydianiline PI, and two kinds of crosslinkers were used: tris(4‐aminophenyl)amine and 1,3,5‐triazine‐2,4,6‐triamine (melamine). The mechanical, thermal and optical properties of the PI hybrid films were investigated. In particular, the transparency and physical properties of the PI hybrid films containing amino‐functionalized GO with homogeneous dispersion were improved. As the content of the crosslinker increased, a crosslinking network was formed between the PI chains, and the stiffness of the hybrid films was increased. The glass transition temperature, heat resistance and mechanical properties were also enhanced. The PI hybrids prepared with a rigid crosslinker exhibited higher optical transparency due to the reduction of the intermolecular charge transfer interactions with increasing interchain spacing between the PI chains. © 2018 Society of Chemical Industry

Photoconductive polyimides derived from a novel imidazole-containing diamine

“…As shown in ATR-FTIR spectra (Figure 3), all PI films showed typical infrared absorption bands of aromatic PIs appeared in the range of 1774 cm −1 (C=O, symmetric), 1716 cm −1 (C=O, asymmetric), and 1367 and 1230 cm −1 (C−N), indicating that all pure PI films showed complete imidization after thermal curing, 25 though bulky groups in diamines usually exhibit lower reactivity in the polycondensation reaction. 26 All PI films were also identified by 1 H NMR spectra.…”

Fast Spectroscopic Gamma Scintillation Using Hafnium Oxide Nanoparticles–Plastic Nanocomposites

“…The EWLT significantly increased from 55.2 to 81.8% when the DVB amount increased from 2 to 5 vol %. This may be attributed to the interchain spacing increase, thus reducing packing density and scattering. , However, the 8.5 mm-thick nanocomposite had a notably lower EWLT (66.6%) due to aggravated scattering in the longer light path as was suggested by a 2.5 nm redshift in its peak emission wavelength (Figure S2). The PL spectra were recorded in a transmission geometry where the incident light hit the nanocomposites from one side while the spectrometer sat at the other side along the incident direction.…”

A Novel Diamine Containing Ester and Diphenylethane Groups for Colorless Polyimide with a Low Dielectric Constant and Low Water Absorption

“…As described in Figure 5 a, the PI film showed typical imide group absorption bands at 1721 and 1370 cm −1 due to C-N asymmetric stretching and C=O asymmetrical stretching of the imide group, respectively. Furthermore, there are no N-H stretching vibration absorption bands at approximately 3200–3450 cm −1 or N-H bending vibration absorption bands at approximately 1550–1650 cm −1 due to the primary amine groups, implying that the chemical imidization process was successfully completed [ 44 ]. The 1 H-NMR spectrum of PI is shown in Figure 5 b.…”