The potassium pHospHate were used as esterifying agent and carbamide was used as a catalyzer in preparation of starch pHospHate with high degree of substitution.The production technique was confirmed by the investigation of dosage of esterifying agent and catalyzer,temprture,time and pH of reaction.In details: 100g corn starch +8gKH2PO4+10-12g carbamide,pH=6.5-7,140℃,4.5-5h.A kind of water-soluble starch pHospHates with 0.09 of DS and 1000 mpa.s of viscosity,which contained N,P,K elements 2.1%,3.7%,4.3%respectively,was prepared.A promising starch pHospHates was to be used in the field of agroforestry.
