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为得到不同水解程度的EVA皂化产物,以乙烯-醋酸乙烯酯共聚物(Ethylene-vinyl acetate,EVA)为原料,甲苯为溶剂,氢氧化钠为催化剂使EVA中的乙酰基在碱性作用下进行水解而得到水解产物。通过化学滴定法研究了EVA在不同水解温度、水解时间、碱浓度下的皂化度,并利用红外、核磁对水解产物的结构进行了分析。结果表明:通过控制水解温度、水解时间和碱浓度实现了EVA的可控皂化度,并经13C-NMR分析得出EVA皂化产物有九种不同的序列结构。该研究为今后对EVA进行化学改性提供了基础。
In order to obtain EVA saponification products with different degrees of hydrolysis, ethylene was used as raw materials, toluene as solvent and sodium hydroxide as catalyst to make the acetyl groups in EVA under alkaline action Hydrolysis to obtain the hydrolyzate. The degree of saponification of EVA at different hydrolysis temperature, hydrolysis time and alkali concentration was studied by chemical titration. The structure of hydrolyzate was analyzed by IR and NMR. The results show that the controlled degree of saponification of EVA can be achieved by controlling the hydrolysis temperature, hydrolysis time and alkali concentration. The 13C-NMR analysis shows that the EVA saponified product has nine different sequence structures. This study provides the basis for the chemical modification of EVA in the future.