聚丙烯酸丁酯/受阻酚阻尼杂化体系的相容性研究

Study on Compatibility of Butyl Polyacrylate/Hindered Phenol Damping Hybrid System

受阻酚等小分子存在易自聚集析出的问题,影响阻尼性能。为了研究杂化体系长期使用的稳定性,使用熔点降低法和溶度参数法测定了四种不同结构受阻酚和聚丙烯酸丁酯(PBA)间的Flory-Huggins相互作用参数χ,并绘制了热力学相图。研究表明,随着温度向熔点方向升高,χ越来越小,杂化体系呈现上临界共溶温度相行为(UCST)。紫外可见分光光度透光率测试结果以及广角X射线衍射(WAXRD)结果验证了所绘制热力学相图的准确性。χ值的大小受聚合物-受阻酚间氢键强度和受阻酚分子结构的影响,提高小分子-大分子间氢键强度可有效降低χ值,增大受阻酚羟基受阻程度,并且增大受阻酚的范德华体积会使χ变大,影响体系稳定性。相图对优化杂化体系的受阻酚类型及用量,预测杂化体系相行为具有良好的指导作用。

Small molecules,such as hindered phenols,are prone to self-aggregation and precipitation,which affects their damping properties.In order to study the long-term stability of hybrid systems,the Flory-Huggins interaction parametersχbetween poly(butyl acrylate)(PBA)and four kinds of hindered phenols were measured by melting point reduction method and solubility parameter method.The thermodynamic phase diagrams were drawn.The results showed that theχdecreased with the increase of temperature toward melting point,and the system possessed an upper critical temperature(UCST)behavior.The accuracy of the thermodynamic phase diagram was verified by the results of the transmittance test of ultraviolet spectrophotometer and wide-angle X-ray diffraction(WAXRD).The value ofχdepended on the intensity of hydrogen bond between polymer and hindered phenol and the molecular structure of hindered phenol.Increasing the degree of hindered phenolic hydroxyl and Van der Waals volume of hindered phenol would increaseχand decrease the stability of the system.Phase diagrams is useful to optimize the type and dosage of hindered phenols in hybrid systems and to predict the phase behavior of hybrid systems.