Synthesis Of New Modified Lignin Amine Asphalt Emulsifiers And Its Investigation By Online FTIR

Using lignin as the raw material of producing asphalt emulsifier has the advantages of reducing the economic cost of asphalt emulsifier,the raw materials coming from a wide range of sources,the producing process simple.The investigation on the synthesis of lignin-amine asphalt emulsifier based on lignin provides a new way for the comprehensive utilization of lignin.It can reduce the environmental pollution caused by black liquor in paper making industry.It is in keeping with the policies of circular economy,effective comprehensive utilization of resources,energy conservation and environmental protection of our country.Firstly,three new cationic type modified lignin-amine asphalt emulsifiers were synthesized in this paper.The factors affecting the yield of the reaction were investigated.The chemical structure of the product was confirmed by static FTIR.The synthesis process was monitored by React IR 4000 online FTIR technique(dynamic FTIR,Mettler Toledo corporation).Secondly,nine new modified lignin-amine asphalt emulsifiers were got by further modification of these three modified lignin-amine asphalt emulsifiers.Finally,the emulsifying and mixing performance properties were also investigated in the paper.1.Synthesis of asphalt emulsifier(1)A new cationic type asphalt emulsifier of(3-hydroxyethylethylenediamine/formaldehyde modified lignin amine(target product a)was synthesized by the reaction of lignin,?-hydroxyethylethylene diamine(HEED),sodium hydroxide and formaldehyde.The optimum reaction process condition was obtained.The yield reaches 39.54%at the optimum reaction condition of lignin 20.0 g,?-hydroxyethylethylene diamine 0.10 mol,sodium hydroxide dosage(p)0.43 g,the feedstock mole ratio(n)of formaldehyde to ?-hydroxyethylethylene diamine 3.16,reaction temperature 80 ?,and reaction time 3 h.(2)A new cationic type asphalt emulsifier of diethylenetriamine/formaldehyde modified lignin amine(target product b)was synthesized by the reaction of lignin.diethylenetriamine(DETA),sodium hydroxide and formaldehyde.The optimum reaction process condition was obtained.The yield reaches 56.03%at the optimum reaction condition of lignin 20.0 g,diethylenetriamine 0.10 mol,sodium hydroxide dosage(p)0.43 g,the feedstock mole ratio(n)of formaldehyde to diethylenetriamine 2.00,reaction temperature 80 C,and reaction time 2.5 h.(3)A new cationic type asphalt emulsifier of N-aminoethylpiperazine/formaldehyde modified lignin amine(target product c)was synthesized by the reaction of lignin,N-aminoethylpiperazine(AEP),sodium hydroxide and formaldehyde.(4)Nine new cationic lignin-amine asphalt emulsifiers(product A,B,C,D,E,F,G,H and J)were synthesized by the reaction of lignin,sodium hydroxide,diethylenetriamine(DETA),N-aminoethylpiperazine(AEP),?-hydroxyethylethylene diamine(HEED),formaldehyde,acrylic acid,trimethylamine aqueous solution(or triethylamine,or triethanolamine aqueous solution),industrial hydrochloric acid,and epichlorohydrin(ECH).2.Structural characterizationThe chemical structures of the asphalt emulsifier products(target product a,b,c,A,B,C,D,E,F,Q H and J)were analyzed by static FTIR.The synthesis process was detected by React IR 4000 online FTIR technique and the intermediate was found.Regarding to the data and information of the experiment,the reaction mechanism was proposed.3.Mixing performance(1)The lignin-amine asphalt emulsifiers(product a,b,c,A,B,C,D,E,F,G,H and J)have satisfactory emulsification effect to asphalt.The prepared asphalt emulsion showed higher storage stability.The mixing test with aggregate shows that the asphalt emulsifier(product a,b,c,A,B,C,D,E,F,G,H and J)belongs to rapid-set or medium-set emulsifier of asphalt.The emulsifier has potential application prospects in the field of tack coat and chip seal in highway construction and maintenance engineering.(2)The influence of further modification of asphalt emulsifiers on the mixing time was investigated by the determination of mixing time of different asphalt emulsifiers.