Low-dielectric polyimide constructed by integrated strategy containing main-chain and crosslinking network engineering

Preparation and performance testing of novel bendable optically transparent fluorinated hyperbranched linear long chain segment poly(amide-imide) films

“…Table 3 lists the values of the dielectric constants of the PAIs at 1 MHz, which are between about 2.10 and 2.48. The reason for the lower dielectric constant of PAI films is that the action of the trifluoromethyl group and pendant unit causes the structural units to have lower molar polarizability and larger molar volumes, 56,57 and the dielectric constants fit in the following order from the largest to the smallest: PAI-1 > PAI-2 > PAI-4 > PAI-3.…”

Impact of ring structure and conjugation on the dielectric properties of polyimides at a high frequency of 10–40 GHz

“…Consequently, materials with low D k and D f values at high frequency offer a vital advantage. Numerous low-k polymers have been applied and researched extensively, such as polyimide (PI), [8][9][10][11][12][13][14] polybenzimidazole (PBI), 15,16 polyethylene terephthalate (PET), [17][18][19] poly(phenylene ether). [20][21][22][23] Among these abundant polymers, PIs demonstrate comprehensive performance, including a high glass transition temperature (T g ), a low coefficient of thermal expansion (CTE), and a high mechanical strength.…”

Increasing Twist Rigidity to Prepare Polyimides with Low Dielectric Constants and Dissipation Factors over a Wide Temperature Range

“…31 Unlike D k , which intuitively depends on molecular polarizability (α) and the number of polarized molecules per unit volume (N), in terms of D f , there is a lack of mature theory for D f . In previous research, interchain interactions have been strengthened using rigid chain copolymerization, 31 crosslinking, 32 crystallization, 8 and blending 33 to restrict the deflection of polar groups in the molecular chain and lessen the D f . Additionally, it has been investigated employing the insertion of tiny body positive groups at particular positions to restrict via interactions between groups inside the chain to minimize the D f , while this raises the D k .…”