The Synthesis And Photoproperties Of Triazinyl Aminstilbene Polymeric Fluorescent Brighteners

Triazinyl aminostilbene fluorescent brighteners (FBs for short) is an important type of dyes,which reduce yellowness and increase fabric brightness and whiteness by a process of absorption light in the near ultraviolet region of the spectrum and re-emit the light as violet-blue fluorescence in the visible region of the spectrum. They are the most widely used type of fluorescent brighteners in the market recently in many industry fields, such as paper manufacture,textile,leather,paint and detergents and so on because of their excellent properties and moderate price. In solution these FBs have low photo resistance,which will lead to decrease the degree of whiteness. In addition, they cannot be used in strong acid/alkali conditions and its environmental impact, thus their application is restricted.The basic structure of chromogen in polymeric fluorescent brighteners (PFBs for short) remains the same, so PFBs have increasing whiteness properties, too. Covalent bonds between chromogen and macromolecule chains enhances their photochemical stability and photo resistance, increases their whitening performance and fluorescence quantum yield. Resistance to wet process and organic solvent is greatly improved, and the less environmental impact be referred to as an new environmental efficient products. PFBs expands the using range of traditional fluorescent brighteners in paper manufacture and printing because of being more suitable for dyeing in strong acid/ alkali conditions. PFBs have higher dyeing whiteness and uptake, no move, easy to metabolism even erosion into organisms, so they are high safety.Polymeric fluorescent brighteners have also been active field in the polymeric material for years, but how to design and synthesis new structure PFBs or functional polymeric fluorescent brighteners with outstanding performance such as using in strong acid and alkali conditions and asymmetrical ploymeric fluorescent brighteners as well as potential applications have still attracted the world attention recently. Domestic research reports rarely. Foreign research mainly focus on triazine-stilbene fluorescent brighteners copolymers by fluorescence monomer with unsaturated polymerizable allyloxy group or acrylamide group in the triazine ring polymerization with styrene or acrylonitrile. Covalent bonds between chromogen and macromolecule chains enhance their photochemical stability, increase their fluorescence quantum yield and whitening performance being coated in substrate. But synthetic PFBs have poor water-soluble and single synthetic products, the application is limited.Main research is divided into two parts:synthetic experiment and performance testing experiment.(1) Synthesis of symmetrical triazinyl aminostilbene polymeric fluorescent brighteners.①Series of polymeric-4,4'-bis(4-N'-methyl-l-piperazi- nyl-R-1,3,5-triazin-2-ylamino)-stilbene-2,2'-disulfonic acid-imine allylic chlorine-acrylamide FBs are synthesized by polymerization of acrylamide and N'-methyl-l-piperazinyl-imine allylic chlorine quaternary ammonium salt from quaterisation reaction with allylic chlorin. Comparing with4,4'-bis(4-N'-methyl-l-piperazinyl-R-1,3,5-triazin-2-ylamino)-stilbene-2,2'-disulfonic acid, photo resistance and heat resistant of polymeric 4-N'-methyl-l-piperazinyl-imine allylic chlorine-acryla-mide is enhanced, and water soluble is improved. Whitening performance and adsorptivity for paper fiber, resistant to hard water and washing fastness ability as well as tensile strength is enhanced notably.The synthetic products have bigger concenteation of fluorescence quenched and wide pH use range.②The series of polymeric-4,4'-bis(4-N-ylmaleimide-R-1,3,5-triazin-2-ylamin-o)- stilbene-2,2-disulfonic acid -styrene fluorescent brightenes are synthesized by using styrene, maleic anhydride (MAH) as monomers modified by tradition triazinyl aminostilbene fluorescent brightener with N,N'- dimethyl formamide (DMF) as solvent, acetic anhydride as dehydrating agent. Comparing with non polymeric fluorescent brighteners, covalent bonds of N-triazene-maleimide polymeric fluorescent brighteners between chromogen and macromolecule chains can enhance chromogen photochemical stability, increase their whitening performance and fluorescence quantum yield. Meanwhile, with the solvent polarity reduce, fluorescence quantity greatly increases, the maxima absorbed wavelength and emission wavelength happen redshift.The type of substituents in the triazine ring can affect directly the concentration of trans and cis isomers, but not affect significantly absorption-fluorescence assignments. In equilibrium of aqueous solution, the concentration of trans-isomers prevails for N-triazene-maleimide polymeric fluorescent brighteners containing aliphatic residues as substituents whereas the aromatic residues increase the cis-isomers.③The synthesis of hanging type macromolecule fluorescent brighteners by of polyhydroxyl or ployamino macromolecule. Replacing one of amino compounds with polyvinyl alcohol (PVA) and chitosan(CS), hanging type triazinyl aminostilbene macromolecule fluorescent brighteners (CS-FBs, PVA-FBs) are synthesized through condensation reaction of fluorescent small molecules like as gourd are hanged one by one according to certain spacing to carbon chain of 4,4'-diaminostilbene-2,2'-disulfonic acid with cyanuric chloride (CC) and two kinds of amino compounds, one of them is CS and PVA. The polyhydroxyl fluorescent brighteners can enhance adsorptivity for paper fiber, the tensile strength and burst index as well as light resistance of coated paper notably.(2) Synthesis of asymmetrical ploymeric fluorescent brighteners.Using 4-nitro-4-aminostilbene-2,2'-disulfonic acid (ANSD) as raw materials, containing 4-nitro group fluorescent brighteners got hold through variant amine compounds replacing the chlorine of triazine rings with condensation reaction and nitro-group being deoxidated to amino group by using sodium bisulfide.The asymmetrical ploymeric fluorescent brighteners are synthesized through condensation reaction with another dibasic triazine compound grafted polyadipoyl diethylene triamine.Comparing with asymmetrical and symmetrical FBs, the active fluorescent component being bonded in the macromolecule chains of the asymmetrical polymeric fluorescent brighteners can enhance chromogen photochemical stability, in addition to the more substituents in triazine ring, their respective photophysical and photochemistry can play an additive synergistic effect and promote each other,the ultraviolet absorption and dyeing properties increases greatly, photo and heating stability as well as water-soluble is improved. The quenche concenteation of polyadipoyl diethylene triamine FBs is 5×10-4 g/mL.(3) Synthesis of amphoteric quaternary ammonium salt fluorescent brighteners.The amphoteric quaternary ammonium salt fluorescent brighteners are synthesized by ring-opening reaction of glycidyl trimethyl ammonium chloride (GTMAC) with triazinyl aminostilbene fluorescent brighteners (FBs) under substituting sulfhydryl, amino and hydroxyl group for one of amino compounds. The absorption spectra and fluorescence spectra of quaternary ammonium salt FBs is a good mirror symmetry relations. Comparing with the traditional FBs, such as CXT and VBL,the light stability is greater, the acid/alkali resistance and ultraviolet absorption performance are improved. The adsorptivity for paper fiber, washing fastness and rubbing fastness ability is enhanced notably. Whitening performance and physical tensile strength of quaternary ammonium salts fluorescent brighteners are higher Use scope is expanded, but fluorescence emission performance is lower slightly.(4) Performance testing experiment.The photophysics and photochemical properties of the synthesis target products is studied, such as ultraviolet absorption and fluorescenc emmission performance, light resistance performance, fluorescence quantum yield, stockes shift and so on. Meanwhile the influence factors on fluorescence performance are discussed, such as pH value in solution, light irradiation time, concentration, organic solvent, etc. The structures and purity are characterized and determined by IR, elemental analysis, nuclear magnetic resonance, HPLC and so on.