Development of Inkjet Printable Formulations Based on Polyorganosilazane and Divinylbenzene

Within this work, ink formulations based on polyorganosilazane (OPSZ) and divinylbenzene
(DVB) were developed to be processed by inkjet printing. The formulations were studied
regarding their rheological, structural, and thermal properties. The rheological results show that
the new formulations meet the requirements of the inkjet printer by showing both low viscosity
(below 20 mPas at printing temperature) and Newtonian flow behavior even at high shear rates.
Additionally, the inks have surface tensions in the range of 21 to 26 mN/m2. First, printing experiments
of single layers were successfully conducted and show that the developed formulations can be
processed by inkjet printing. The inks were crosslinked by UV light and then pyrolyzed at 1100 C
resulting in a ceramic yield between 75 and 42%, depending on the ink formulation. The crosslinking
behavior was studied via FTIR spectroscopy, and the results reveal that crosslinking occurs mainly
via free-radical polymerization of the vinyl group. Furthermore, the results indicate that silicon
carbonitride (SiCN) was formed after the pyrolysis. The results of the electrical properties of the
... mehr
amorphous ceramics differ in dependence on the amount of DVB in the formulation. A maximum
electrical conductivity of 1.2 S/cm􀀀1 was observed for a UV-cured sample with a high amount of
DVB pyrolyzed at 1100 C. The generation in electrical conductivity is given by the formation of free
carbon derived most likely by DVB.