Low-melting siloxane-bridged phthalonitriles for heat-resistant matrices

• Published in: European polymer journal 2015-05, Vol.66, p.452-457
• Main Authors: Babkin, Alexander V., Zodbinov, Elvek B., Bulgakov, Boris A., Kepman, Alexey V., Avdeev, Viktor V.
• Format: Article
• Language: English
• Subjects: Bridges (structures); Column chromatography; Heat-resistance; Low-melting thermosets; Monomers; Oligomers; Phthalonitrile; Processability; Reinforced plastics; Siloxanes; Stability; Thermal properties
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2015.03.015

[Display omitted] •New low melting stable siloxane-bridged phthalonitrile monomers are reported.•Obtained monomers possess Tg lower than any previously reported data.•Thermal and thermooxidative properties remained at the level for phthalonitriles. New low-melting phthalonitrile monomers were obtained by introduction of different flexible siloxane bridges such as –O–SiPh2–O– and –O–SiPhMe–O–. In spite of the presence of the siloxane groups the considered monomers were separated as single compounds by column chromatography with good yields (up to 90%). The synthesized monomers possessed Tg=12–27°C which were by a decade lower than it had been reported for phthalonitrile monomers before and even lower than the lowest Tg=41°C detected for phtalonitrilic oligomers. The cured monomers demonstrated high thermal and thermooxidative stabilities at the same level as described earlier for that type of polymer matrices. Thus a significant decrease of the Tg of the suggested monomers dramatically expands the processing window for the whole class of phthalonitrile matrices for reinforced plastics.