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CN-122011962-A - Preparation method of cassava starch-waste syrup-vinasse protein composite formaldehyde-free binder

CN122011962ACN 122011962 ACN122011962 ACN 122011962ACN-122011962-A

Abstract

The invention discloses a preparation method of a tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder, which adopts tapioca starch, waste syrup and vinasse protein as main raw materials to prepare an environment-friendly formaldehyde-free binder. The preparation method comprises the steps of firstly, preprocessing the distillers 'grains protein extract, mixing the distillers' grains protein extract with starch milk prepared in a certain proportion, adding waste syrup after gelatinization, adjusting the pH value of the mixed solution, and adding a cross-linking agent to realize cross-linking reaction to prepare the binder. The binder prepared by the invention has no formaldehyde emission in the production and use processes, and realizes the high-value utilization of various biomass resources such as waste syrup, vinasse, tapioca starch and the like. The adhesive prepared by the invention has good adhesive property and water resistance, is environment-friendly, and can be widely applied to the field of artificial board manufacturing.

Inventors

  • ZHANG BO
  • WU WEITAO

Assignees

  • 张波
  • 吴维涛

Dates

Publication Date
20260512
Application Date
20260312

Claims (10)

  1. 1. The preparation method of the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder is characterized in that the binder is formed by mixing tapioca starch, waste syrup, vinasse protein, a cross-linking agent, water and a pH regulator, and comprises the following steps: Step 1), preparing a choline chloride-urea DES green solvent, mixing vinasse and the DES solvent according to a liquid-solid ratio of 1:5, stirring and extracting at 60 ℃, and then separating solid from liquid to obtain an extracting solution; step 2), adding ethanol as a stripping agent into the extracting solution to precipitate and separate out vinasse protein and polysaccharide to obtain a precipitate, and separating and drying the precipitate to obtain the vinasse protein and the polysaccharide; Step 3), dissolving the vinasse protein obtained in the step 2) in water to form a vinasse protein solution with the concentration of 10% -20%, and stirring until the vinasse protein solution is dissolved; Step 4), mixing tapioca starch and water in a weight ratio of 1:2-1:3 to form starch milk; Step 5), adding the vinasse protein solution in the step 3) into the starch milk in the step 4) to obtain a mixed solution according to the weight ratio of starch to vinasse protein dry solids of 100:10-100:50, and stirring at the same time; step 6), heating and gelatinizing the mixed solution obtained in the step 5) to 60-65 ℃ and stirring; step 7), adding the waste syrup into the gelatinized mixed solution in the step 6) according to the weight ratio of starch to waste syrup dry solids of 100:20-100:40, and stirring and mixing; Step 8), adding a dilute sodium hydroxide solution into the mixture obtained in the step 7), and adjusting the pH value of the mixture to 8-9; step 9), adding the cross-linking agent into the mixture obtained in the step 8) according to the weight ratio of 100:5-100:15 of dry solids of the starch and the cross-linking agent, and stirring for 10-15 minutes; step 10), heating the mixture obtained in the step 9) to crosslink to 85-95 ℃ and reacting for 30-60 minutes at a constant temperature; And 11) transferring the binder reacted in the step 10) to room temperature, and continuously stirring and cooling to below 40 ℃ to obtain the composite formaldehyde-free binder.
  2. 2. The preparation method of the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder is characterized by comprising the following steps of: 1) Preparing a choline chloride-urea DES green solvent, mixing vinasse and the DES solvent according to a liquid-solid ratio of 1:5, stirring and extracting for 2 hours at 60 ℃, then centrifuging to obtain an extracting solution, adding ethanol into the extracting solution to precipitate and separate out protein and polysaccharide, and separating and drying a precipitate to obtain vinasse protein; 2) Adding 100 g cassava starch into 250g of water, stirring to form starch milk, weighing 30g of vinasse protein solid powder, dissolving in 170 g of water to prepare a solution with the concentration of 15%, regulating the pH value to 8.0 by using a dilute sodium hydroxide solution, adding the protein solution into the starch milk under stirring, heating to 65 ℃ for gelatinization, adding waste syrup 50g, regulating the pH value to 8.5 by using dilute sodium hydroxide after stirring, adding 10g of citric acid, stirring for 15 minutes, heating to 90 ℃, preserving heat for reacting for 45 minutes, stirring and cooling to room temperature after the reaction is finished, and obtaining the composite formaldehyde-free binder.
  3. 3. The preparation method of the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder is characterized by comprising the following steps of: 1) Preparing a choline chloride-urea DES green solvent, mixing vinasse and the DES solvent in a liquid-solid ratio of 1:5, stirring and extracting for 2 hours at 60 ℃, then centrifuging to obtain an extracting solution, adding ethanol into the extracting solution to precipitate and separate out protein and polysaccharide, and separating and drying the precipitate to obtain vinasse protein; 2) Adding 100 g parts of tapioca starch into 250g of water, stirring to form starch milk, dissolving 30 g parts of vinasse protein solid powder into 170 parts of g water to prepare a solution with the concentration of 15%, regulating the pH value to 8.0 by using a dilute sodium hydroxide solution, adding the protein solution into the starch milk under stirring, heating to 65 ℃ for gelatinization, adding waste syrup 50g, regulating the pH value to 8.5 by using dilute sodium hydroxide after stirring, adding 10g parts of borax, stirring for 15 minutes, heating to 90 ℃, preserving heat for reacting for 45 minutes, stirring and cooling to room temperature after the reaction is finished, and obtaining the composite formaldehyde-free binder.
  4. 4. The preparation method of the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder is characterized by comprising the following steps of: 1) Preparing a choline chloride-urea DES green solvent, mixing vinasse and the DES solvent in a liquid-solid ratio of 1:5, stirring and extracting for 2 hours at 60 ℃, then centrifuging to obtain an extracting solution, adding ethanol into the extracting solution to precipitate and separate out protein and polysaccharide, and separating and drying the precipitate to obtain vinasse protein; 2) Adding 100 g cassava starch into 250 g cold water, stirring to form starch milk, weighing 50 g vinasse protein solid powder, dissolving in 283 g water to prepare a solution with the concentration of 15%, regulating the pH value to 8.0 by using a dilute sodium hydroxide solution, adding the protein solution into the starch milk under stirring, heating to 65 ℃ for gelatinization, adding waste syrup 50 g, regulating the pH value to 8.5 by using dilute sodium hydroxide after stirring, adding 10g citric acid, stirring for 15 minutes, heating to 90 ℃, preserving heat for reacting for 45 minutes, stirring and cooling to room temperature after the reaction is finished, and obtaining the composite formaldehyde-free binder.
  5. 5. The method for preparing the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder according to claim 1, wherein in the step 9), the adding amount of the cross-linking agent is 5% -15% of the weight of the dry starch.
  6. 6. The method for preparing the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder according to claim 1, wherein in the step 9), the cross-linking agent is selected from one of borax, citric acid and ammonium zirconium carbonate.
  7. 7. The method for preparing the tapioca starch-waste syrup-distillers' grains protein composite formaldehyde-free binder according to claim 1, wherein in the step 9), a silane coupling agent is added as an interfacial binding force improving auxiliary agent.
  8. 8. An application method of a tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder is characterized in that the composite formaldehyde-free binder is prepared by the preparation method of claim 1, and the application method comprises the following steps: 1) Sizing, namely coating or spraying the composite formaldehyde-free binder on a substrate to be bonded to carry out sizing; 2) Paving and prepressing, namely paving the glued raw materials in a die to form a plate blank, and prepressing at room temperature to remove air; 3) Cold pressing, namely placing the pre-pressed slab into a cold press, applying a pressure of 1-3MPa at room temperature, and maintaining the pressure for 30-60 minutes; 4) And (3) post-curing and drying, namely placing the cold-pressed plate into an oven or a drying room, and performing heat treatment for 2-4 hours at the temperature of 100-120 ℃.
  9. 9. The method of claim 8, wherein the adhesive is applied in an amount of 10% -20% by weight of the oven dry weight of the base material.
  10. 10. The method for applying the tapioca starch-waste syrup-distillers' grains protein composite formaldehyde-free binder according to claim 8, wherein the method is characterized by comprising the following steps: the base material is wood dust, straw powder or cotton stalk.

Description

Preparation method of cassava starch-waste syrup-vinasse protein composite formaldehyde-free binder Technical Field The invention relates to the technical field of binders for artificial boards, in particular to a preparation method of a tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder. Background Formaldehyde-based adhesives such as urea-formaldehyde resins and phenol-formaldehyde resins have been dominant in the artificial board industry for a long time because of their excellent adhesive strength and water resistance. However, such binders can continuously release formaldehyde during use, contaminate indoor air, harm human health, and their raw materials are derived from non-renewable fossil resources. Therefore, development of adhesives that are renewable in sources, free of formaldehyde emissions during production and use, has become an urgent need for industry development. The starch binder has the advantages of wide raw material sources, low price, no toxicity, environmental protection and the like. However, the traditional starch binder has the defects of poor water resistance, insufficient bonding strength and the like, and is difficult to meet the performance requirements of industrial plate production bonding. In order to improve the performance of the starch binder, the prior art usually adopts a method of chemical modification or addition of synthetic resin, but the cost is often increased or harmful substances such as formaldehyde are introduced. Waste syrup in sugar industry is a byproduct produced in the sugar production process, is rich in reducing sugar, can be used as a plasticizer and a crosslinking reaction accelerator of a starch binder, and has limited individual modification effect. Vinasse is a main byproduct of the wine industry, has huge annual output and is rich in protein and polysaccharide, but is mainly treated in the form of low-added-value feed or fertilizer at present, and high-value utilization of resources cannot be realized. How to extract the vinasse protein efficiently and apply the vinasse protein to the modification of starch-based adhesive, and meanwhile, the technology is environment-friendly and cost-controllable, and the technical problem to be solved in the field is urgent. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide the preparation method of the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder, which adds the vinasse protein extracted by DES into a tapioca starch-waste syrup binder system, realizes zero formaldehyde release in the preparation and use processes while obviously improving the bonding strength and the water resistance, and provides a new way for recycling high-value utilization of waste syrup and vinasse. The raw materials of the tapioca starch-waste syrup-vinasse protein composite formaldehyde-free binder comprise tapioca starch, sugar industry waste syrup (for filtering impurities), vinasse protein, a cross-linking agent, water and a pH regulator. The preparation method of the cassava starch-waste syrup-vinasse protein composite formaldehyde-free binder comprises the following steps: step 1), preparing a choline chloride-urea DES green solvent, mixing the distilled grain and the DES solvent according to a liquid-solid ratio of 1:5, stirring and extracting for 2 hours at 60 ℃, and separating solid from liquid by centrifugation or filtration after the extraction is finished to obtain an extracting solution. And 2) adding ethanol as a stripping agent into the extracting solution obtained in the step 1) to precipitate and separate vinasse protein and polysaccharide to obtain a precipitate, and separating and drying the precipitate to obtain a mixture of the vinasse protein and the polysaccharide. And 3) dissolving the vinasse protein obtained in the step 2) in water to form a vinasse protein solution with the concentration of 10-20%, and stirring to ensure uniform dissolution. And (3) initially adjusting the pH value of the vinasse protein solution to be neutral or slightly alkaline by using sodium hydroxide or hydrochloric acid. And 4) mixing the tapioca starch and cold water in a weight ratio of 1:2-1:3, and stirring at a low speed to form uniform starch milk. And 5) adding the vinasse protein solution pretreated in the step 3) into the starch milk obtained in the step 4) according to the weight ratio of starch to vinasse protein (dry solids content) =100:10-100:50, so as to obtain a mixed solution, and simultaneously keeping stirring at a low speed. And 6) heating and gelatinizing the mixed solution obtained in the step 5) to 60-65 ℃ and continuously stirring. And 7) adding the waste syrup into the gelatinized mixed solution in the step 6) according to the weight ratio of the starch to the waste syrup (calculated as dry solids) of 100:20-100:40, and continuously stirring and uniformly mixing. And 8) adding a dilute sodium hydroxide