| Abstract: | Bisphenol A‐based benzoxazine that contained oligomers (oligo‐Ba) was prepared from bisphenol A, formaline, and aniline. Curing reaction of oligo‐Ba with bisoxazoline and the properties of the cured resin were investigated. Consequently, the ring‐opening reaction of benzoxazine ring occurred, and then the phenolic hydoroxyl group generated by the ring‐opening reaction of benzoxazine ring reacted with oxazoline ring. It was found that the cure induction time and cure time of the molten mixture from oligo‐Ba and bisoxazoline could be reduced and also the cure temperature could be lowered, compared with those from bisphenol A‐based benzoxazine, which contained no oligomers (Ba), and bisoxazoline. The melt viscosity of the molten mixture from oligo‐Ba and bisoxazoline was kept 0.1–10 [Pas] at 140°C even after 40 min, the molten mixture from oligo‐Ba and bisoxazoline showed good flowability below 140°C as well as that from Ba and bisoxazoline. However, above 160°C the curing reaction of oligo‐Ba with bisoxazoline proceeded more rapidly than that of Ba with bisoxazoline. The cured resin from oligo‐Ba and bisoxazoline showed good heat resistance and water resistance, compared with the cured resin from Ba and bisoxazoline. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2331–2339, 2001 |
