Synthesis of low-molecular-weight epoxy resins under phase transfer catalysis (PTC) conditions
Polimery 1997, No 2, 96
Single-stage synthesis of low-M epoxy resins from dian (4,4'-isopropylidenediphenol) and epichlorohydrin has been studied in the presence of NaOH in relation to various PTC catalysts used. The epoxy number (LE), Mn, Mw and the degree of polydispersity (Pd) of the resulting products were studied in relation to the PTC catalyst applied. Optimum process conditions were established, viz., the dian—epichlorohydrin—NaOH (as aq.50% solution) ratio 1:3:2, methylene chloride as organic solvent medium, and trioctylbenzylammonium chloride or triethanolbenzylammonium chloride as a PTCcatalyst. The PTC conditions have enabled low-M epoxy resins (M = 360—370) to be synthesized at room temperature and the amount of epichlorohydrin used for the reaction to be considerably reduced.