# Tailoring Properties Through Functionalized Alicyclic Diamine Towards Solution-Processable High-Performance Polyimide Films

## TL;DR

A new fluorinated diamine compound was used to create high-performance polyimide films with excellent solubility, optical transparency, and thermal stability for advanced electronics.

## Contribution

A novel fluorinated diamine monomer was synthesized and used to create solution-processable polyimide films with exceptional combined properties.

## Key findings

- The polyimide films show outstanding solubility in various organic solvents, including low-boiling ones like chloroform.
- Films exhibit high water contact angles (up to 109.4°) and minimal water absorption (as low as 0.26%), indicating strong hydrophobicity.
- The materials maintain excellent thermal stability with 5% mass loss temperatures exceeding 416 °C.

## Abstract

A novel fluorinated diamine monomer, 4,4′-((bicyclo[2.2.1]hept- 5-ene-2,3-diylbis (methylene)) bis(oxy))bis(3- (trifluoromethyl) aniline) (NFDA), featuring a tailored alicyclic norbornane core, flexible ether linkages, and pendant trifluoromethyl groups, was successfully synthesized. This monomer was polymerized with six commercial dianhydrides to produce a series of poly(amic acid) precursors, which were subsequently converted into high-performance polyimide (PI) films via a thermal imidization process. The strategic integration of the alicyclic, ether, and fluorinated motifs within the polymer backbone resulted in materials with an exceptional combination of properties. These PI films display outstanding solubility in a wide range of organic solvents, including low-boiling options like chloroform and tetrahydrofuran, highlighting their superior solution processability. The films are amorphous and exhibit remarkable hydrophobicity, evidenced by high water contact angles (up to 109.4°) and minimal water absorption (as low as 0.26%). Furthermore, they possess excellent optical transparency, with a maximum transmittance of 86.7% in the visible region. The materials also maintain robust thermal stability, with 5% mass loss temperatures exceeding 416 °C, and offer a desirable balance of mechanical strength and flexibility. This unique set of attributes, stemming from a rational molecular design, positions these polyimides as highly promising candidates for next-generation flexible electronics and advanced photovoltaics.