In order to obtain low‐k material with good comprehensive properties, a trifluoromethyl‐containing organosiloxane with thermocrosslinkable vinyl and benzocyclobutene groups is designed and synthesized through the Piers–Rubinsztajn reaction. After treating at high temperature, the organosiloxane changed to form a cross‐linked polysiloxane (called as c‐FSi‐BCB). c‐FSi‐BCB exhibits good dielectric properties with dielectric constant (Dk) of 2.60 and dielectric loss (Df) of 1.49 × 10−3 at a high frequency of 5 GHz. Importantly, c‐FSi‐BCB maintains such good dielectric properties and exhibits low water uptake of below 0.076%, even after immersing it in boiling water for 96 h. c‐FSi‐BCB also displays good thermostability with a 5% weight loss temperature (T5d) of 453 °C. These data indicate that this fluorinated organosiloxane is suitable as the matrix resin for the fabrication of devices used in 5G communication.

A new biobased functional norbornene was synthesized by the Diels–Alder reaction between cyclopentadiene and the fluorinated eugenol. Based on the norbornene monomer, a new polynorbornene was prepared with a high molecular weight (M n = 78 000 Da) by the standard ring opening metathesis polymerization (ROMP). This polymer displayed good film-forming ability and can be postpolymerized to form a cross-linked network at high temperature (>150 °C) via the [2 + 2] cycloaddition reaction of trifluorovinyl ether (−OCF2CF2) groups. The cross-linked polymer exhibited good transmittance (T % > 90% at 550 nm) and high thermostability with a 5% weight loss temperature of 412 °C. Moreover, no obvious glass transition temperature (T g) was observed in the DMA measurement when the temperature was elevated near the decomposition temperature of the cross-linked polymer (about 350 °C). The cured resin displayed an average dielectric constant (D k) of below 2.65 with average dissipation factor (D f) of 4.3 × 10–3 for the frequencies varying from 40 Hz to 25 MHz. The cross-linked polymer film also possessed good hydrophobicity with a contact angle of 104° (water on the surface of the film) and a surface energy of 26.8 mJ m–2. These data indicate that the combination of norbornene and the fluorinated eugenol can greatly improve properties of polynorbornene, which could have potential application in microelectronic industry. Thus, this contribution may provide a new way for the usage of the biomass.

Biomass-derived high-performance polymers have recently received much attention because they are easily available and renewable. More recently, researchers have been interested in low-dielectric polymers derived from biomass feedstock. These polymers display good dielectric properties and high thermostability, as well as good mechanical properties, implying that they have potential application in microelectronic industry, especially in fifth-generation communication (5G). This review summarizes recent progress in low dielectric polymers based on the biomass, including the synthesis and properties of different types of biomass resins such as epoxy resins, benzoxazine resins, benzocyclobutene resins, perfluorocyclobutane resins, cyanate eaters, polyester resins, phthalonitrile resins, and a functional maleimide.