The organic montmorillonite (OMMT) modified urea-formaldehyde (UF) resin adhesives were prepared by base-acid-base synthetical technology and adding OMMT to the different stage of the synthesis.The technical characteristics of adhesives were tested.The structure of the sample was characterized by X-ray diffraction

infrared spectroscope and scanning electron microscope.The thermal property was measured by thermogravimetric analysis.The results indicated that with the addition of OMMT

the free formaldehyde content in adhesives decreased and the bonding strength increased.And the OMMT added had obviously decreasing aldehyde effect at the first stage and obviously reinforcing effect at the second stage.The SEM results indicated that the sheet structure of the OMMT in the modified adhesive showed a curled shape due to the matrix covered or squeezed.The XRD results indicated that the crystallinity of OMMT/UF adhesives was lower than that of UF adhesives

which suggested that the arrangement regularity of the carbonyl and amino groups in UF resin adhesives was destroyed because of the introduction of the OMMT.The FTIR results indicated that there were a lot of free urea and low content of free formaldehyde in the modified UF resin adhesive.The TG results indicated that the TG curve of the modified resin adhesive moved to higher temperatures

and the thermal decomposition temperature increased.