Epoxy prepolymers cured with boron trifluoride‐amine complexes, 3. Polymerization mechanism of a prepolymer containing epoxy groups

The reaction of a diepoxy prepolymer (2) initiated by the BF3‐complex of 4‐chloroaniline (3), solubilized in poly(ethylene oxide) (PEO) of molecular weight 300, was studied. An initial induction period was observed, followed by a pseudo‐stationary stage with decreasing reaction rate due to gelation. In the pseudo‐stationary stage, the homopolymerization rate is given by the expression: Rp = k[2]1 · [3]·−0,55 · [PEO]·0,57. In addition to 2, we also used a Novolac prepolymer 4. Different networks were prepared and analyzed by thermal and mechanical techniques, and their water‐absorption rates were measured.