Non-porous and porous materials prepared by cross-linking of polyhydromethylsiloxane with silazane compounds

作者：Olejarka Justyna; Lacz Agnieszka; Olejniczak Zbigniew; Hasik Magdalena^*

来源：European Polymer Journal, 2018, 99: 150-164.

DOI：10.1016/j.eurpolymj.2017.12.018

• Polysiloxanes
• Silazanes
• Polymer networks
• Porous polymers

In the work, polyhydromethylsiloxane (PHMS) was cross-linked with two vinylsilazanes: 1,1,3,3-tetramethyl1,3-divinyldisilazane ((SiNSivi)-Si-vi) or 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasilazane (((SiN)-Si-vi)(4)) in the presence of Karstedt's catalyst. When the reactions were carried out in solvent-free conditions non-porous polysiloxane-silazane networks were obtained. The processes conducted in high internal phase emulsion (HIPE) resulted in macroporous materials. Their non-porous or porous morphology was established by SEM studies. They were also analyzed by elemental analysis, swelling measurements, FTIR and Si-29 MAS-NMR spectroscopies and thermogravimetry coupled with mass spectrometry (TG/MS). Results showed that the non-porous networks contained high amounts of silazane moieties and were fairly hydrolytically stable. In contrast, contents of silazane units in most porous materials were low. Moreover, hydrolysis of Si-H groups of PHMS followed by condensation of the resulting Si-OH groups took place in HIPE conditions. This led to additional cross-linking of PHMS by siloxane bonds. During preparation of porous systems using (SiNSivi)-Si-vi, hydrolysis of silazane bonds (Si-N) also occurred. All the materials studied in the work contained reactive Si-H groups and therefore exhibit a great potential for various applications. Presence of nitrogen atoms in their structure as well as porosity may be additional advantages.

• 出版日期2018-2