Method for synthesizing straw bonding phenolic resin

The invention discloses a method for synthesizing straw bonding phenolic resin. The method comprises the following steps of: (1) adding 100 weight parts of phenol, 5 to 30 weight parts of a modifying agent and 0.5 to 3 weight parts of an acid catalyst into a reactor, raising the temperature to between 130 and 150 DEG C, keeping a constant temperature for 3 to 5 hours, and reducing the temperatureto between 60 and 80 DEG C; (2) adding 10 to 25 weight parts of sulfite and 60 percent of formaldehyde into the reactor of the step (1), regulating the temperature to be between 60 and 100 DEG C, andstirring at the constant temperature until the viscosity at the temperature of 25 DEG C is between 300 and 500CP, wherein the molar ratio of the phenol to the formaldehyde is 1:2-3; (3) regulating the temperature in the reactor of the step (2) to be between 80 and 100 DEG C, adding the rest of formaldehyde, and stirring at the constant temperature of between 80 and 100 DEG C until the viscosity at the temperature of 25 DEG