黄顶菊秸秆pH值、缓冲容量及脲醛树脂固化特性的研究

Study on pH Value,Buffer Capacity and UF Resin Curing Characteristics of Flaveria bidentis(L.) Kuntze Straw

对黄顶菊秸秆粉末进行冷水、热水、1%NaOH预处理,测定其pH值、缓冲容量、脲醛树脂固化时间。实验结果表明:未处理及经冷水、热水、1%NaOH处理后的黄顶菊秸秆的pH平均值分别为4.27、4.87、5.05、8.66;未处理及经冷水、热水、1%NaOH处理后的黄顶菊秸秆的酸缓冲容量平均值分别为0.627 6、0.646 4、0.687 6、2.091 6;未处理和经冷水、热水处理后黄顶菊秸秆的碱缓冲容量平均值分别为0.156 9 mmol、0.161 6 mmol、0.171 9 mmol;未处理及经冷水、热水、1%NaOH处理后黄顶菊秸秆的脲醛树脂胶固化时间平均值分别为91 s、123 s、127 s、135 s。pH值越低,酸缓冲容量越低,秸秆粉末与脲醛树脂固化时间越短,反之固化时间则延长。综合考虑,未处理的黄顶菊秸秆粉末更有利于脲醛树脂胶的固化。

Pretreatment of Flaveria bidentis（ L.） kuntze straw power is conducted using cold water,hot water and 1%NaOH to measure its pH value,buffer capacity and UF resin curing time. The experimental result shows that the pH value average,acid buffer capacity average,alkali buffer capacity average and UF resin average curing time of untreated Flaveria bidentis（ L.） kuntze straw and Flaveria bidentis（ L.） kuntze straw treated with cold water,hot water and 1% NaOH are 4. 27,4. 87,5. 05,8. 66; 0. 627 6,0. 646 4,0. 6 876,2. 091 6; 0. 156 9 mmol,0. 161 6 mmol,0. 171 9 mmol; 91 s,123 s,127 s,135 s respectively. The lower the pH value,the lower the acid buffer capacity,the shorter the straw power and UF resin curing time,vice versa. Comprehensive consideration shows that untreated Flaveria bidentis（ L.） kuntze straw power is more conducive to the curing of UF resin adhesive.