Research On Synthesis And Performance Of Multifunctional Brightness Stiabilizer

Triazinyl aminostilbene fluorescent brighteners is a type of compound, which can increase fluorescence quantum yield by a process of absorption light in the near ultraviolet region of the spectrum and emit a high-intensity light as violet–blue fluorescence in the visible region of the spectrum. They are most widely used of fluorescent brighteners in many fields, such as textile, paper manufacture, synthetic fiber and detergents and so on. Recent studies show that the fluorescent brighteners used in high-yield pulp can not only improve the initial whiteness but also improve the brightness stability of high yield pulp. But triazinyl aminostilbene fluorescent brighteners have low water solubility and light stability and fiber binding capacity, which can limit their scope and economic benefits. These deficiencies have been overcome by macromolecular modified in recent years. According to this design idea, a series of multifunction light stabilizers are synthesized.This study is divided into synthetic experiments and optical properties test. On one hand two series of multifunctional light stabilizers were synthesized based on triazinyl aminostilbene fluorescent brightener molecules: polyhroxy light stabilizers and polyether multifunctional light stabilizers. And then their multifunctional will be improved through introducing the small molecular group. On the other hand a new 7-hydroxy-4-methyl coumarin multifunctional light stabilizer was synthesized based on 7-hydroxy-4-methyl coumarin fluorescent brightener.Firstly, with cyanuric chloride as the crosslinking monomer and 4,4’-diamino stilbene-2,2’-disulfonic acid(DSD acid) as the raw materials, according to their characteristics by controning the reaction temperature and p H, the polyhroxy light stabilizers(FWA) was synthesized through joining the carbohydrate molecules and the multifunctional small molecule in the same molecule by the size of nucleophilicity method. Secondly, the polyether multifunctional light stabilizer(PEG-FBs) was synthesized through joining the 2,4-dihydroxy-benzophenone(a ultraviolet absorber) or other small molecule and the series of polyethylene glycol(PEG) in the same molecule with cyanuric chloride as the crosslinking monomer, which had the function of fluorescent whitening and restraining yellowing. Finally, employing the Pechmann method, 7-hydroxy-4-methyl coumarin fluorescent brightener was synthesized through dehydration condensation of resorcinol and ethyl acetoacetate under acid condition. A new 7-hydroxy-4-methyl coumarin multifunctional light stabilizer(FBA) was synthesized by introducing 2,4-dihydroxy-benzophenone(a ultraviolet absorber) and 4-amion-2,2’,6,6’-tetra-mentylniperidine(a free radicals capturer) into the molecule of 7-hydroxy-4-methyl coumarin fluorescent brightener, using cyanuric chloride as the crosslinking monomer.The molecular structures were characterized by IR spectra and 1H NMR, the physical properties were examined by UV spectra and photolu-minescence(PL) spectra, the application effect of the light stabilizer in paper sheet were tested. In application experiments, the compounds were used chemimechanical pulps and their anti-yellowing effects on handsheet from chemimechanical pulps were evaluated as the surface sizing agent on handsheet by using the ultraviolet aging apparatus, compared with the traditional fluorescent whitening agent triazine stilbene fluorescent brighteners(VBL). The results showed that the active ingredient of triazine-stilbene fluorescent brighteners was 28.86%, while the active ingredient of the polyether multifunctional light stabilizer(PEG-FBs2) was 61.8% after illumination. The fluorescence was quenched when the concentration of the multifunctional light stabilizer was over 1×10-3 kg / L, its usage can be enlarged than VBL(1×10-5 kg / L). The coumarin multifunctional light stabilizer is more effective on brightness stability comparing with 7-hydroxy-4-methyl coumarin fluorescent brightener, the decline of PC was 6.9 and 1.2 less than the blank sample and 7-hydroxy-4-methyl coumarin fluorescent brightener. The brightening effect and light stability of the multifunctional light stabilizer are nice in the performance of application. At the same time, its light stability are improved obviously.