Novel low‐dielectric constant and soluble polyimides from diamines containing fluorene and pyridine unit

Abstract

Polyimides (PI's) with low‐dielectric constant and excellent organic solubility have broad application prospects in the electronic field. Herein, this study designed a series of novel, low dielectric, organic soluble PI films by creatively introducing fluorene and pyridine ring into diamine monomers. Because of the noncoplanar structure of fluorenyl and the polarization of pyridine ring, PI films achieved a low‐dielectric constant (2.22–3.09 at 10 MHz) and excellent organic solubility. Even in some organic solvents with low‐boiling points, these PI films still exhibited outstanding solubility. In addition, all the films possessed high‐tensile strength (≈120 MPa) and excellent optical transparency (>70%, 450 nm). It was worth noting that the glass transition temperature of films was all above 280°C and 5% weight loss temperature (T5%) was at 486–553°C. In general, the novel high‐performance low‐dielectric PI films are expected to be used in the field of microelectronics.

Highly soluble fluorinated polyimides with promising gas transport performance and optical transparency

“…Moreover, 6FDA-BASA exhibited the highest T g , which is attrib-uted to 6FDA with a highly rigid and poorly mobile substituent, such as the bulky -C(CF 3 ) 2 moiety. 45,46 The presence of -Oand -C(CH 3 ) 2 helps to increase the flexibility of the polymer backbone, resulting in lower T g of BPADA-BASA than ODPA-BASA. It seems that the low T g of ODPA-BASA may stem from the overall increasing chain mobility of the polymer backbone because the ether linkage of the ODPA increases its chain flexibility.…”

Constructing high-performance low-temperature curable PI materials by manipulating the side group effects of diamine

“…16 Besides, the nitrogen heterocycle could increase the nucleophilicity of diamines to attack carbonyl carbon, facilitate the acylation reaction and decrease the curing temperature as reported. 20–24 Artem’eva et al investigated the catalytic action of the pyrimidine fragments in the process of imidization, and they considered that there were two influences of the pyrimidine ring on thermal curing: (1) the energy barrier of imidization might be decreased by this ring and (2) the pyrimidine ring could be conducive to more rapid and complete resynthesis of polyamide acid partly damaged by thermocyclization. 20 Subsequently, Li et al reported pyrazine based diamine, and prepared a series of low-temperature curable PI films with an ID of about 73.1% when curing at 200 °C.…”

In-situ polymerization of low-dielectric fluorinated nano carbon/polyimide composites with low-temperature curable property

“…One important challenge is about the data transmission loss in the high frequency communication which would result in high signal transmission loss, destroy signal integrity [9][10][11]. At the same time, the dielectric loss of the insulating dielectric materials will also increase in the high frequency [12][13][14]. Therefore, polymers with low dielectric constant and low dielectric loss have become an important research direction.…”