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Abstract In order to synthesize phenolic polysiloxane with stable phenolic hydroxyl content and reactivity, Hexamethyldisilazane (HMDS) and tert-butyldimethylsilyl (TBDMS) were used as the protectant of phenolic hydroxyl of eugenol. After protecting, eugenol was reacted with hydrogen-terminated polysiloxane under the platinum catalyst through hydrosilylation reaction. Eugenol polysiloxane was finally obtained after removing protectant under glacial acetic acid or hydrochloric acid. The protective effect of HMDS and TBDMS on eugenol phenolic hydroxyl under HMDS and TBDMS these both different conditions and its deprotection effect in glacial acetic acid and hydrochloric acid were discussed. The results showed that, compared with TBDMS, the protective effect of HMDS protectant was better. Without solvent and catalyst, the protective effect of HMDS on eugenol had achieved 100% when the reaction temperature was 40 ℃. Adding solvent, acidic catalyst or heating had inhibition effect on this eugenol protection reaction. Compared with acetic acid methanol solution, hydrochloric acid methanol solution was more effective on deprotection reaction of phenolic hydroxyl and its yield reached 94.3%. The characterization of the production by nuclear magnetic resonance hydrogen spectrum and infrared spectrum analyses indicated that eugenol polysiloxane was prepared successfully.
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Received: 28 September 2020
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2020, Vol. 33 
