Study On Preparation Of LPF From Phenolation Modification Lignin

Lignin was the second renewable natural macromolecule organic matter in plant kingdom. At present, the pulp and paper industry was developed at top speed, produced a large number of waste liquid to pollute the environment. From year to year it can refined0.5million tons of industrial lignin, but only10%of the industrial lignin can be reasonable utilization. Phenolic resin was one kinds of famous adhesive used in industry, it has good adhesion properties and good waterproof property, but also has some disadvantages like high limits of harmful substances and production of raw materials is not renewable. Used the phenolation modification industrial lignin can replace phenol or formaldehyde to prepare lignin phenolic resin, can improve some of the shortcomings of the phenolic resin, this study can reduce the dependence of the phenolic resin synthetic industrial petrochemical byproducts, and also can take advantage of the resources of industrial lignin, reduce phenolic synthetic resin costs, it has great economic value and social significance..The thesis focuses on phenolation modification lignin, used the modified lignin to replace phenol to prepare lignin phenol formaldehyde resin(called "LPF" for short). Chose two kinds of commonly industrial lignin:①Alkali lignin;②Ammonium lignosulfonate.Firstly, analysis the components of two kinds of lignin, study the solubility and the water insoluble matter content, moisture, ash content, lignin content and total sugar content. The results showed that, the moisture content of ammonium lignosulfonate was far greater than the alkali lignin, the two can be dissolved in water, the ash content of alkaline lignin was more than ammonium lignosulfonate, the lignin content of alkali lignin was less than ammonium lignosulfonate, total sugar content of two similar.Secondly, choose four parameters like lignin and phenol ratio(L/P), reaction temperature(T), reaction time(t) and the amount of catalyst(c), study on the residue rate and the brominable substance content of phenol liquefied products. Determined the optimum process conditions of the phenolation modification ammonium lignosulfonate:L/P=50%, T=120℃, t=90min, c=6%; determined the optimum process conditions of the phenolation modification alkali lignin:L/P=40%, T=120℃, t=120min, c=5%.Finally, select the factors like molar ratio of phenol liquefied products and formaldehyde(P/F), catalyst amount(c), reaction temperature(T), reaction time(t), used the single factor experiment design method, study on the bonding strength, free phenol content and free formaldehyde content of LPF, optimized the synthesis technology. Determined the optimum process conditions of the LPF(ammonium lignosulfonate):P/F=1:1.9, c=2%, T=100℃, t=150min; determined the optimum process conditions of the LPF(alkali lignin):P/F=1:2.1, c=5%, T=110℃, t=150min. The comprehensive performance of LPF which prepared in two kinds of optimization of process conditions ware all in line with the relevant national standards of GB/T14732-2006/Wood adhesives:urea formaldehyde, phenol formaldehyde and melamine formaldehyde resins.