The invention relates to a method for preparing carboxymethyl
hydroxypropyl guar gum
powder by a
guar gum sheet one-
step method. The method comprises the following steps of adding
guar gum sheets into an
organic solvent-water
mixed solution, heating the solution to a temperature of 30-80 DEG C, adding a
sodium hydroxide solution into the heated
mixed solution, carrying out an alkalization reaction process for 2-60min, then adding an etherifying agent into the
reaction product, carrying out a reaction process at a temperature of 30-80 DEG C for 30-180min, then carrying out cooling and
filtration, washing the filter residue, carrying out crushing, and carrying out
drying to obtain a finished product. The method utilizes cheap
guar gum sheets as raw materials, realizes carboxymethyl and hydroxyalkyl etherification modification by the one-
step method, and greatly shortens reaction time than a multi-
step method. Through synchronization of carboxymethylation and hydroxyalkylation, processes are simple and convenient, reaction time is short, and the product has low water-insoluble
substance content, good crosslinking performances, good fracture
initiation and sand-carrying functions and good application prospects in the field of
oil field pressing crack liquids. The method has a wide application prospect in the field of
oil field auxiliary agents.