Research On The Synthesis And Properties Of Fluorescent Whitening Agents Containing P-Aromatic Amino

Triazinylaminostilbene type fluorescent whitening agents (FWA) are widely used in many industry fields such as textile, synthetic fibre, plastic, paper manufacture, synthetic detergent and so on because of their excellent properties and moderate price. The conventional product were VBL, BBU and CXT. The domestic study of this type fluorescent whitening agents laid strong emphasis on technical amelioration and industrialisation. The breed and top-grade product is less, the type is all-purpose and lack marker rivalrousness.Considering the problem of this type of fluorescent whitening agents existed in domestic,usingcyanuricchloride,p-aminobenzoicacidand4,4'-aminostilbene-2,2'-disulfo nic acid (DSD acid) as main materials,8 kinds of anionic FWA were synthesized using variant amine compounds replacing the chlorine of triazine rings. First cyanuric chloride reacts with p-aminobenzoic acid. Then the second nucleophilic substitution occurs by adding DSD acid. Aliphatic amino were added and the third nucleophilic substitution proceeds. After that 8 new kinds of anionic FWA were obtained. The otherness of photophysical and photochemical of the new compounds in aqueous solution is tested. It is established that ultraviolet absorption, fluorescent emission performance of the new products were increased. But all products had obvious photoinduced isomerzation phenomena and their lightfastness were also low. So they should be saved without light.Considering the anionic FWA having limited applied range because of their weak acidresistivity and solubility in the acidic condition,the triazinyl aminostilbene fluorescent whitening agents were synthesized through three-step condensation reactions using 4-aminobenzoic acid with cyanuric chloride (CC),4,4'-diamino stilbene-2,2'-disulfonic acid (DSD acid) and aliphatic amines as the basic materials. Here,aliphaticaminesincludingtriethanolamine,triethylamine,N,N-dimethylethanolamin eandN-methyldiethanolamine were used as reactants of the third step condensation reaction. The structural characterization of the synthesized amphoteric fluorescent whitening agents (FWA) was given. The fluorescence emission properties and the dyeing properties of the amphoteric FWA were compared with those of anionic FWA. The result showed that the fluorescence emission efficiency was lower than that of anionic FWA. But the amphoteric FWA was more suitable for dyeing in acidic conditions.The enhancive efficiency by mixed product is hotspot and emphasis of fluorescent whitening agents research. Some products have already been successfully excogitated or put into production in a few foreign companies, but few in domestic research. Basing on the research of the other people,6 compound products were prepared in proportion with 1:1 by two aroma amine at the first step condensation reaction, and the other 4 compound products were prepared in proportion with 1:1 by two amine at the third step condensation reaction. Then 10 compound products containing 2 symmetrical type and 1 asymmetrical type were prepared. The photophysical and photochemical properties of the products were investigated and compared with those of anionic FWA. It was established that the ultraviolet absorption, fluorescent emission performance of complex types fluorescent whitening agents were higher. But they had obvious photoinduced isomerization phenomena and its light stability were also low because of the existence of the asymmetrical FWA.