Tianyong Zhang,Yamei Chai,Suisui Wang,Jianing Yu,Zihao Fang,Shuang Jiang,Bin Li
With the diminishing gap between the internal components of chips, the signal transmission delay poses a substantial threat to chip performance. To enhance the transmission speed of electrical signals, the development of materials with a low dielectric constant (D k ) becomes imperative. Polyimide (PI), categorized as a specialized engineering material, exhibits a high D k (≥3), posing challenges in meeting the requirements of electronic and communication industries. Consequently, a new diamine monomer named BTVFD, characterized by spirobifluorene and cross-linkable tetrafluorostyrol groups, was synthesized. It was copolymerized with 2,2′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-diamine (TFDB) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) to synthetize cross-linkable polyimides (TBPIs) with different BTVFD content. The cross-linked TBPIs (CL-TBPIs) were obtained by thermal cross-linking reaction. The study results demonstrate the D k of PIs is significantly reduced through this effective strategy. Notably, CL-TBPI-2 exhibits outstanding comprehensive performance with low D k (1.88@10 MHz) and dielectric loss (0.00513@10 MHz), low water uptake (0.125 %), high thermal decomposition temperature (5 % weight loss at 553 °C) and glass transition temperature (374 °C), excellent tensile strength (121.8 MPa) and nice transparency and flexibility.
Two new spirobifluorene-based conjugated microporous polymers, TS-TAD and TS-TADP, were constructed via Friedel-Crafts coupling reactions. TS-TAD and TS-TADP possess high BET surface area of 828 and 783 m 2 g −1 , large pore volume of 1.51 and 0.54 cm 3 g −1 , good stability, and display excellent guest uptake of 4.15 and 3.65 g g −1 in iodine vapour as well as reversible adsorption of iodine in solution. The specific surface areas of CMPs were increased by the introduction of bispirofluorene rings compared with the corresponding parent polymers. TS-TAD has a similar structure to TS-TADP, but possesses larger specific surface area and pore values than TS-TADP, hence, TS-TAD has a higher adsorption capacity for iodine than TS-TADP. Moreover, the adsorption rate of TS-TAD is slower than that of TS-TADP in I 2 vapor, while it is faster than that of TS-TADP in cyclohexane solution. We also highlight that the both resulting CMPs exhibit outstanding performance for fluorescent sensing to iodine and nitroaromatic compounds, thus making the resulting CMPs ideal absorbent materials for reversible iodine capture, sensing iodine and nitroaromatic compounds to address environmental issues.
危险品化学品经营许可证（带存储）