The reaction of 1,1,2,2-tetraphenyl- and 1-methyl-1,2,2-tri-phenylcyclopropanes with NOBF4, gave 2-phenyl-2-isoxazolinium tetrafluoroborates via the phenyl migration from 3-phenyl-2-isoxazolidinium or 1-isoxazolinium intermediates.
A resin composition is provided containing a resin (preferably a thermoplastic resin) and an isoxazolidine. The composition exhibits enhanced melt stability and colour stability. The composition is useful for making thermoplastic articles such as extruded sheet and film. Preferably the thermoplastic resin is a polyolefin such as polypropylene. A method for stabilizing thermoplastic polymers is also provided.