脲-异丁醛-甲醛三元缩聚树脂的合成与表征

Synthesis and Characterization of Urea-Isobutyraldehyde-Formaldehyde Terploycondensate

以脲、异丁醛、甲醛为原料,在酸性条件下,合成出三元缩聚树脂(UIFR),考察了合成条件对UIFR软化点和羟基值的影响,并用FT-IR,1H-NMR,TG和GPC对其进行了表征。结果表明,在异丁醛、甲醛摩尔比为1.5,醛、脲摩尔比为6,真空蒸馏温度为140℃、时间为1 h的条件下,合成出的UIFR软化点为90℃,羟基值为32 mgKOH/g,M-n为377 g/mol,且树脂具有良好的溶解性和抗黄变性。FT-IR及1H-NMR结果说明合成反应发生在异丁醛中的α氢原子上。

Urea-isobutyraldehyde-formaldehyde terpolycondensate （UIFR） was synthesized from urea, isobutyraldehyde and formaldehyde under acid condition. Effect of synthesis condition on softening point and OH value of UIFR was investigated. The terpolycondensate was characterzated by FT-IR,^1H-NMR,TG and GPC. It is found that UIFR with softening point of 90℃, OH value of 32mg KOH/g and Mn of 377 g/mol is synthesized when molar ratio of isobutyraldehyde to formaldehyde is 1.5, molar ratio of aldehyde to urea is 6, vacuum distillation temperature and time is 140℃ and 1 h respectively. The terpolycondensate is soluble in most solvents of paints and exhibits excellent yellowing-resistance. FT-IR and ^1H-NMR results show that the reaction occurs in the α-H atom of isobutyraldehyde.