Parylene E

1.  Introduction

The Parylene E,a low κ polymer thin film, with the approximate composition 69% diethylated and 25% monoethylated poly(p-xylylene), is nearly optically isotropic without optical loss, and can be used as candidate materials for optical waveguides. The parylene E is soluble in common laboratory solvents (such as chloroform, toluene), making it useful for  archival conservation , cultural relics protection and other fields. In addition, the heat-treated parylene E has a high-sensitivity adsorption affinity for non-polar VOCs, and can be used in high-sensitivity gas sensors in the future.

2.Parylene E coating example¹

The precursor of parylene E is placed in a sublimation furnace, and the vacuum vapor deposition device is evacuated by a vacuum pump to a degree of below 3 mTorr. The sublimation furnace temperature was set at 120℃, the pyrolysis temperature was set at 650 ℃, and film deposition was carried out at a rate of 10.3 Å/min at room temperature. 

3.parylene E film properties

The melting point of Parylene E film is about 200℃, the glass transition temperature (film thickness 0.7μm) is 32.3-40.2℃, and the dielectric constant at 1MHz is 2.34±0.03. Compared with paryleneN/C/C/HT film, Parylene E  has poor solvent resistance，Its dissolution temperature in common solvents is shown in the table below.

References

1.doi:10.1116/1.1487870, Research on the synthesis process of parylene HT, E film precursors [D], Southeast University.