In order to evaluate the significant effects of curing temperature, solid content, and pH on the pre-curing behavior of the UF resin, the isothermal and non-isothermal thermal behaviors were discussed by differential scanning calorimetry in this work. The results indicated that the temperature and pH showed significant influence on the whole shape of the DSC curves and the conversion at the same time of the UF resin. Meanwhile, the non-isothermal thermal behavior showed that when the UF resin pre-cured for the same time of 30 s, the onset and peak and end temperature of the DSC curves were decreased, and the activation energy and the conversion was also increased with the increasing curing temperature or decreasing pH. Based on the analysis of the contribution rate of the temperature, solid content, and pH on the conversion and heat of pre-curing UF resin, the results indicated that the pH and temperature showed significance effect on the pre-curing action than solid content.
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This work was supported by Undergraduate Innovative Training Program of China (Project No. 201610626068) and Project of Sichuan education department (Project No. 035Z1378).
HX designed the experiments and supervised the research; YC performed the experiments, analyzed the data, and wrote the paper; JX and JQ helped to analyze the data and review the English; SX and FL contributed to the sampling and field work. All authors read and approved the final manuscript.
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