an adhesive suitable for bonding wood is both heat curable and radio frequency curable . this adhesive is composed of an isocyanate - terminated prepolymer and hydrolyzed soy protein having a ph of at least about 9 and advantageously from about 9 to 11 . 5 . the weight ratio of prepolymer to soy protein hydrolyzate ranges from about 70 : 30 to 90 : 10 .