Effects of alicyclic moiety incorporation on the properties of polyimide/silica hybrid films

Abstract

Polyimide (PI)/silica hybrid films were prepared from tetraethyl orthosilicate (TEOS) using a sol‐gel process as well as pyromellitic dianhydride and 4,4‐oxydianiline. 1,4‐Cyclohexanedicarboxylic acid (1,4‐CHDA) was added as a coupling agent. The PI/silica hybrid films were characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, differential scanning calorimetry and wide‐angle X‐ray diffraction. The thermal, tensile and dielectric properties of the hybrid films were measured. The results showed that the tensile and dielectric properties of the hybrid films improved with increasing silica concentration and 1,4‐CHDA content in the PI matrix. Covalent ester bonds were formed between SiOH groups of silica and carboxyl groups of 1,4‐CHDA. As a result, the silica particle size was reduced and dispersed homogeneously in the PI matrix, leading to increased tensile strength and tensile modulus of the typical hybrid film with 1,4‐CHDA (PI‐2), when compared with the PI/silica hybrid film without 1,4‐CHDA at the same silica contents. The presence of an alicyclic moiety containing silica in PI reduced the dielectric constant considerably to 2.83, which was lower than that of pristine PI. Copyright © 2016 John Wiley & Sons, Ltd.

Low Dielectric Constant Polyimide Hybrid Films Prepared by in Situ Blow-Balloon Method

“…The incompatibility between the PI matrix and the inorganic filler is considered to be the main cause of the ductility deficiency of PI/inorganic hybrid films. − Microphase separation control of the PI matrix and inorganic filler are a key point in the preparation. In this work, a blow-balloon method was developed to produce porous PI/rGO films based on our previous study .…”

Synthesis and properties of bisphenol‐Z polycarbonate via melt transesterification

“…As shown in Figure 11 and data in Table 3, the decomposition temperature of BPZ‐PC is slightly lower than that of BPA‐PC, and the residual carbon content of BPZ‐PC also is lower. This may be due to the cyclohexyl groups are prone to undergoing chain reactions through ring opening decomposition at high temperatures, resulting in relatively lower polymer decomposition temperature and residual carbon content 39,40 . However, the difference in thermal decomposition temperatures between the two is not significant.…”

“…This may be due to the cyclohexyl groups are prone to undergoing chain reactions through ring opening decomposition at high temperatures, resulting in relatively lower polymer decomposition temperature and residual carbon content. 39,40 However, the difference in thermal decomposition temperatures between the two is not significant. In comparison, the BPZ-PC still has good thermal performance.…”

Synthesis of a Novel Rigid Semi-Alicyclic Dianhydride and Its Copolymerized Transparent Polyimide Films’ Properties

“…The conventional aromatic PIs display a yellow or brown color caused by the formation of the charge transfer complex (CTC) effect between the donor diamine and the acceptor dianhydride moieties [ 14 , 15 , 16 ]. In order to obtain colorless polyimide (CPI) films, different endeavors have been proposed to achieve the modification of traditional aromatic PI, such as the incorporation of flexible groups [ 17 , 18 , 19 ], large-scale substituents [ 20 , 21 , 22 , 23 ], ring structures [ 24 , 25 , 26 ], fluorine-containing structures [ 27 , 28 , 29 ], and twisted or non-planar structures [ 30 , 31 ] in its backbone to limit the formation of the CTC effect to improve the film’s transparency. Generally, the decreased CTC effect of PI films will degrade other properties, including its thermal stability and mechanical properties [ 32 ].…”