Method for preparing phenol-formaldehyde resins, resin materials and method for preparing resin molding materials
A method for preparing a phenol-formaldehyde resin is provided. The method includes extracting a biomass pyrolysis oil to obtain a first phenolic mixture, mixing the first phenolic mixture, furfural and an alkaline catalyst to proceed to a first polymerization reaction to form a phenol-formaldehyde resin precursor solution, and adding the alkaline catalyst to the phenol-formaldehyde resin precursor solution to proceed to a second polymerization reaction to form a phenol-formaldehyde resin solution. The disclosure also provides a resin material prepared from the phenol-formaldehyde resin. The disclosure further provides a method for preparing a resin molding material.
1. A method for preparing a phenol-formaldehyde resin, comprising the following steps:
extracting a biomass pyrolysis oil to obtain a first phenolic mixture;
mixing the first phenolic mixture, furfural and an alkaline catalyst to proceed to a first polymerization reaction to form a phenol-formaldehyde resin precursor solution;
adding the alkaline catalyst to the phenol-formaldehyde resin precursor solution to proceed to a second polymerization reaction to form a phenol-formaldehyde resin solution; and
adding an alcohol during the first polymerization reaction, wherein the alcohol and the first phenolic mixture have a weight ratio of 0.25:1-10:1, wherein the alcohol is ethanol, methanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, n-hexanol or t-butanol.
2. The method for preparing a phenol-formaldehyde resin as claimed in claim 1 , wherein the first phenolic mixture comprises at least two of phenol, 2-cresol, 4-cresol, 3-cresol, guaiacol, 2,6-dimethyl phenol, 2,4-dimethyl phenol, 4-ethyl phenol, m-ethyl phenol, 2-methoxy-4-methyl phenol, 1,2-benzenediol, 3,4-xylenol, 4-ethyl-m-cresol, 3-methoxy catechol, 3-methyl pyrocatechol, 1,4-benzenediol, 4-ethyl guaiacol, 4-methyl catechol, 4-vinyl-2-methoxy phenol, 2-methyl-1,4-benzenediol, 2,6-dimethoxy phenol, 2-methoxy-4-propyl phenol, isoeugenol, 2-methoxy-4-propyl phenol, 2,6-dimethoxy-4-allyl phenol, or 3-allyl-6-methoxy phenol.
3. The method for preparing a phenol-formaldehyde resin as claimed in claim 1 , wherein the biomass pyrolysis oil is extracted by an extractant, and the extractant is ethyl acetate, propyl acetate, butyl acetate, methyl isopropyl ketone, methyl isobutyl ketone, methyl i-amyl ketone, ethyl ethyl ketone- or toluene.
4. The method for preparing a phenol-formaldehyde resin as claimed in claim 3 , wherein the extractant further comprises a second phenolic compound.
5. The method for preparing a phenol-formaldehyde resin as claimed in claim 4 , wherein the second phenolic compound comprises phenol, 2-cresol, 4-cresol, 3-cresol, guaiacol, 2,6-dimethyl phenol, 2,4-dimethyl phenol, 4-ethyl phenol, m-ethyl phenol, 2-methoxy-4-methyl phenol, 1,2-benzenediol, 3,4-xylenol, 4-ethyl-m-cresol, 3-methoxy catechol, 3-methyl pyrocatechol, 1,4-benzenediol, 4-ethyl guaiacol, 4-methyl catechol, 4-vinyl-2-methoxy phenol, 2-methyl-1,4-benzenediol, 2,6-dimethoxy phenol, 2-methoxy-4-propyl phenol, isoeugenol, 2-methoxy-4-propyl phenol, 2,6-dimethoxy-4-allyl phenol, or 3-allyl-6-methoxy phenol, or a combination thereof.
6. The method for preparing a phenol-formaldehyde resin as claimed in claim 4 , wherein the second phenolic compound and the biomass pyrolysis oil have a weight ratio of 0.1:1-1:1.
7. The method for preparing a phenol-formaldehyde resin as claimed in claim 1 , wherein the furfural and the first phenolic mixture have a weight ratio of 0.1:1-4:1.
8. The method for preparing a phenol-formaldehyde resin as claimed in claim 1 , wherein the first polymerization reaction has a reaction temperature greater than or equal to 130° C. and smaller than or equal to 160° C.
9. The method for preparing a phenol-formaldehyde resin as claimed in claim 1 , wherein the second polymerization reaction has a reaction temperature greater than or equal to 70° C. and smaller than 130° C.
10. The method for preparing a phenol-formaldehyde resin as claimed in claim 1 , further comprising diluting the phenol-formaldehyde resin solution to form a phenol-formaldehyde resin diluent.
11. The method for preparing a phenol-formaldehyde resin as claimed in claim 10 , wherein the phenol-formaldehyde resin solution is diluted with a second alcohol.
12. The method for preparing a phenol-formaldehyde resin as claimed in claim 10 , further comprising impregnating a matrix with the phenol-formaldehyde resin diluent to form a resin-impregnated material.
13. The method for preparing a phenol-formaldehyde resin as claimed in claim 12 , further comprising hot-pressing the resin-impregnated material to form a resin molding material.
14. The method for preparing a phenol-formaldehyde resin as claimed in claim 1 , wherein the alcohol and the first phenolic mixture have a weight ratio of 0.25:1-0.6:1.