Synthesis and properties of quaternary ammonium salt fluorescent brighteners

Triazinyl aminostilbene fluorescent brighteners (FBs) can be synthesized through three-step condensation reaction of 4, 4'-diamino stilbene-2, 2'-disulfonic acid (DSD acid) with cyanuric chloride (CC) and two amino compounds. The quaternary ammonium salt fluorescent brighteners were synthesized by changing reactants of the third condensation reaction. Triethylamine and triethanolamine were used to replace diethylamine and diethanolamine. The ultraviolet ray absorption in solutions, photoinduced isomerization phenomena, fluorescence emission properties and application properties of quaternary ammonium salt FBs and nonquaternary ammonium salt FBs were investigate. The acid/alkali resistance of quaternary ammonium salt FBs was higher and the application was wider, but the ultraviolet ray absorption and fluorescence emission performance were lower than those of nonquaternary ammonium salt FBs. At the same time, quaternary ammonium salt FBs had obvious phenomena of photoinduced isomerization and its light stability was also low.