Conversion of a Biorenewable Plant Oil (Anethole) to a New Fluoropolymer with Both Low Dielectric Constant and Low Water Uptake

The conversion of a biorenewable plant oil (anethole) to a new fluoropolymer with both low dielectric constant and low water uptake is reported here. First, cationic polymerization of plant oil by using CF3SO3H as an initiator gave a polymer, which was then functionalized by introducing the thermocrosslinkable -OCF=CF2 groups via a three-step procedure. The obtained fluoropolymer can be easily thermally converted to an infusible and insoluble cross-linked network exhibiting low water uptake (<0.24%, in water of 96 degrees C for 4 days) and low dielectric constant (<2.64 at a range of frequencies varying from 1.0 to at 30 MHz at room temperature). TGA and DMA data showed that the cross-linked network had 5 wt % loss temperature of 400 degrees C (in N-2) and a T-g of 160 degrees C, respectively. Nanoindentation tests indicated that the cross-linked film had an average hardness of 0.239 GPa and a Young's modulus of 6.11 GPa. These results mean that the new polymer derived from biorenewable anethole is comparable to the petroleum-based materials, implying that the low k polymers widely utilized in microelectronic industry will have a new sustainable feedstock supply.