Synthesis Of And Performance Of Water Reducing Agent From Phenols In Bio-Oil As A Concrete Additive

As the most abundant and cheapest renewable resources,biomass resources have high development and application value and a wide range of potential market applications,which produced more than 350 billion tons by photosynthesis each year.The composition of lignocellulosic biomass mainly consists of cellulose,hemicellulose and lignin.Among them,lignin is an aromatic high polymer composed of oxyphenylpropanol or a derivative thereof.Bio-oil derived from fast pyrolysis of biomass contains a large amount of phenols due to the decomposition of lignin.The utilization of phenols in bio-oil has received recent attention.In this work,phenols were extracted from bio-oil,and a series of new water reducing agent were prepared from bio-phenols.The synthesis conditions were tested and their application properties were tested.The research of the thesis provides a new way to broaden the application of phenolic compounds in bio-oil.This research broadens the application of phenols in bio-oil.The bio-oil obtained from pyrolysis of pine wood was used as raw material to extract phenols.The extracted phenols were called extract phenols.The reaction process of sulfonated bio-phenol formaldehyde polycondensate type water reducing agent?SBF?was studied by sulfonation and polycondensation of bio-phenol.Firstly,the distribution of various bio-phenols in oil/water phase was studied with ethyl acetate as extractant.Secondly,using bio-phenols as raw material,the sulfonation characteristics of different bio-phenols in the sulfonation reaction process were studied,and their degree of sulfonation and acidity were measured.In the case of SBF content of 1%,the bio-phenol/formaldehyde?molar ratio?was in the range of 1:0.3-1.1,and the effect of the amount of formaldehyde on the performance of the SBF water reducing agent was investigated.The representative bio-phenols?phenol,guaiacol and 2-methylphenol?were used as raw materials to study the properties of the prepared water reducing agent and the effect of Na₂SO₄ and clay on the water-reducing properties of SBF.When the bio-phenol/formaldehyde molar ratio is 1:1 and the dosage?folding?is 1%,the initial fluidity of the cement paste reaches a maximum of 185 mm,which has good moisture retention in 1.0 h.The water reduction rate of cement mortar was 13.1%,and the compressive strength at 3 d,7 d and 28 d was significantly improved.The biophenol-naphthalene copolymer water reducing agent?C-FDN?was prepared by copolymerization of sulfonated bio-phenols/sulfonated naphthalene with different molar ratios.The factors,which effect the performance of FDN,such as the amount of sulfonated bio-phenols,copolymerization and physical compounding were studied.The process of preparing C-FDN by copolymerization with sulfonated naphthalene was studied by using phenol,guaiacol and 2-methylphenol as raw materials,and the performance of the prepared water reducing agent was tested.The effect of the molar ratio of sulfonated bio-phenols and sulfonated naphthalene on the performance of C-FDN.The results show that when the sulfonated bio-phenols/sulfonated naphthalene?molar ratio?is 3:7 and the dosage?defining?is1%,the initial cement paste fluidity of C-FDN reaches a maximum of 218 mm at 1.0.The fluidity of the cement paste after 1.0 h and 2.0 h is better than that of the naphthalene water reducing agent.The water-reducing rate of cement mortar of C-FDN is 21.6%,and the compressive strength at 3 d,7 d and 28 d is basically the same as that of naphthalene water reducing agent.The mixed biomass-based water reducing agent?B-PS?was synthesized by using thioglycolic acid as chain transfer agent,ascorbic acid and hydrogen peroxide as initiators,and its application performance was tested.The influence of clay on B-PS was investigated.It was found that the amount of chain transfer agent,hydrogen peroxide and ascorbic acid had a significant effect on the performance of the B-PS.The chain transfer agent had a greater influence on the average relative molecular mass of B-PS,which in turn affected the initial fluidity and cement paste moisture retention of the B-PS.The amount of hydrogen peroxide affects the polymerization rate of B-PS,and the amount of ascorbic acid has a great influence on the color of B-PS.When the amount of thioglycolic acid is 0.35%of TPEG,the amount of hydrogen peroxide is 0.1%of TPEG,and the ratio of n?H₂O₂?/n?ascorbic acid?is 4:1,the mud resistance and moisture retention of B-PS are much better than polycarboxylic acid-based water reducing agent under the same dosage.