Characterization of pre-curing behavior of urea-formaldehyde resin affected by different temperatures

3rd International Conference on Agricultural and Biological Sciences

农业科学;生物科学

Chen, Y.Z.^1,2 ; Xiao, H.^1,2

College of Forestry, Sichuan Agricultural University, Chengdu, Sichuan

611130, China^1

Key Laboratory of Wood Industry and Furniture Engineering, Sichuan Agricultural University, Chengdu, Sichuan

611130, China^2

关键词: Activation energies (Ea);    Cross-linking degree;    Increasing temperatures;    Isothermal temperature;    Lower temperatures;    Network structures;    Thermal behaviors;    Water evaporation;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/77/1/012007/pdf
DOI  :  10.1088/1755-1315/77/1/012007

来源: IOP

【 摘 要 】

Differential scanning calorimetry (DSC) was applied to investigate the thermal behavior of pre-curing urea-formaldehyde (UF) resin as affected by different temperatures; the activation energies (Ea) in different stages during the pre-curing course were analyzed by Kissinger method. The results indicated that the curing time was decreased with temperature increasing. Under isothermal temperature, the DSC curves of pre-curing UF resin shifted to shorter time, the conversion increased with increasing temperature. In dynamic scanning, with the pre-curing degree increasing, the DSC curves shifted to lower temperature, while both the onset and peak temperature decreased due to the cross-linking degree increased. The Ea and Z value decreased obviously firstly due to the concentration and reactivity of the reactants increased with water evaporation in the first stage, and then the increasing cross-linking degree and the formation of the network structure lead to both the Ea and Z value increasing in the second stage, indicating that the pre-curing behavior appeared.