| abstract |
Strengthening resins and methods for making and using same. The strengthening resin can include a polyamine partially cross-linked with a bridging moiety and having azetidinium ions. The bridging moiety can be derived from a functionally symmetric cross-linker. The functionally symmetric cross-linker can include a diisocyanate, a 1,3-dialkyldiazetidine-2,4-dione, a dianhydride, a diacyl halide, a dienone, a dialkyl halide, or any mixture thereof. |