Preparation of fluorescent brighteners modified by polyadipoyl diethylene triamine and its application in papermaking

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 fluorescent brighteners modified by polyadipoyl diethylene triamine (PPC-FBs) were synthesized by changing reactants of the third condensation reaction, in which PPC is used to replace one of the amino compounds. The experimental results showed that whiteness and light stability of paper were obviously improved by using PPC-FBs in paper coating. The optimal dosage for FBs in coating pigments was identified through experiments.