Research on Phenol Liquefied Products of Peanut Shell-urea-formaldehyde Resin Adhesive
HOU Xing'ai, SUN Fengwen, LIU Longlong, MI Ling
2018, 52 (6):
The phenol liquefied product of peanut shell was used as raw material to prepare the phenol liquefied product of peanut shell-urea-formaldehyde(PLPUF) resin adhesive. The optimal ratio of PLPUF resin adhesive was studied by orthogonal test, and its comprehensive performance was improved. The results showed that the substance ratios of first batch of urea(U1)/the second batch of urea(U2), liquefaction products(PL)/urea(U总), and the total amount of liquefied product and urea(PL+U总) to the amount of formaldehyde(F) were 3:1, 1:1.5 and 1:1, respectively, which were the best ratio of PLPUF resin adhesive preparation. Under these conditions, the ratio of the bonding strength reached 0.83 MPa, the solid content was 47.11%, and the free formaldehyde content was 0.05%. With the phenolic resin adhesive as the standard, the PLPUF resin adhesive could meet the requirements of the wood industry resin. The viscosity of PLPUF resin gradually increased as time went on. When the resin was stored for 5-15 days, the bonding strengths were 0.87-1.15 MPa. After 22 days, the bonding strength reduced to 0.74 MPa. Therefore, the conditions of use be met within 22 days. In the FT-IR spectra of PLPUF resin, the stretching vibration peaks such as amide C=O and C—N appeared, indicating that urea participated in the reaction and modified resin, and the FT-IR absorption peaks of the resin before and after the addition of the curing agent were the same. Combined with the DSC curve, the addition of the curing agent did not change the structure of PLPUF resin, but could improve the curing process of the PLPUF resin and decrease the curing temperature and reaction heat.
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