Wood based panel cross-linkable starch modified urea formaldehyde resin adhesive and preparation method thereof

The present invention relates to a wood based panel cross-linkable starch modified urea formaldehyde resin adhesive and a preparation method thereof. The preparation method comprises: adding a formaldehyde aqueous solution to a reaction kettle, adjusting the pH value to 8.5-8.8with sodium hydroxide, adding first batch of urea, heating to a temperature of 70-90 DEG C, and carrying out thermal insulation for 30-45 min; adjusting the pH value to 4.7-5.1, and carrying out a reaction to achieve the T-4 viscosity cup viscosity measurement value of 17-18 s at a temperature of 30 DEG C; adjusting the pH value to 6.0-6.5, adding second batch of urea, controlling the temperature at 80-90 DEG C, and carrying out a reaction to achieve the T-4 viscosity cup viscosity measurement value of 18-19 s at a temperature of 30 DEG C; adjusting the pH value to 7.0-7.5, adding third batch of urea, controlling the temperature at 75-80 DEG C, carrying out thermal insulation for 10-40 min, and cooling; adding fourth batch of urea when