受阻酚杂化体系的氢键强度和数量与阻尼性能的关联

Correlation between Hydrogen Bonding Strength and Numbers of Polymer/Hindered Phenol Hybrids and Damping Properties

考察了含3个受阻酚羟基的1,1,3-三(2-甲基-4-羟基-5-叔丁基)丁烷(CA)与多种丙烯酸树脂共混物的玻璃化转变温度(Tg)和阻尼性能。CA的分子内自聚氢键强度远小于同聚丙烯酸酯的分子间氢键强度,小分子在聚合物中具有良好的分散稳定性。对于聚合物中含有甲氧基的杂化体系而言,除了羰基与酚羟基的氢键作用,还可能存在甲氧基与酚羟基之间的氢键作用,因此氢键数量较多。动态机械分析测试(DMA)表明,杂化体系的阻尼性能随CA质量分数的增加而提高,并且随着聚合物基体中甲氧基数目比例的提高,阻尼增效逐渐增强,其中聚丙烯酸甲氧基乙酯杂化体系(POEA/CA)具有最优异的阻尼性能。这些结果说明对于同一种小分子而言,小分子与聚合物之间实际形成的氢键数量越多,小分子对聚合物的阻尼增效越强。

The glass transition temperatures （Tg） and damping properties of different blends consisting of 1 ,1 ,3-tris （2-methyl-4-hydroxy-5-ieri-butyl） butane （CA） containing three hindered phenolic hydroxyl groups and various acrylic polymers were investigated in this paper. The results showed that the intramolecular hydrogen bonding of CA was much weaker than the intermolecular one between acrylic polymer and CA. The small molecule had good dispersion stability in the polymer. There probably existed extra hydrogen bonding between the methoxyl and phenolic hydroxyl groups besides that between the carbonyl and the hydroxyl groups in hybrids which contained methoxyl groups. The dynamic mechanical analysis （DMA） results showed that the damping properties were improved by the addition of CA. Upon increasing the ratio of methoxyl in the polymer structure, the improvement of damping properties became more and more significant. Among them,the poly（methoxyethyl acrylate） hybrid （POEA/CA） showed the best. Accordingly, in the case of the same small molecule, more hydrogen bondings led to better damping properties.