聚天冬氨酸酯聚脲的动态力学行为研究

Research on the Dynamic Mechanical Properties of Polyureas Based on Polyaspartic Esters

通过聚天冬氨酸酯(PAE)与脂肪族异氰酸酯六亚甲基二异氰酸酯(HDI)三聚体/聚四亚甲基二醇(PTMG)预聚物反应,合成了一系列PAE聚脲,考察了PAE种类、软段分子量及成型温度对聚脲动态力学性质的影响。实验结果表明,三官能度PAE-F扩链的聚脲具有较高的低温和高温储能模量(E’)及硬段玻璃化转变温度(Tgh),其微相分离程度也高于二官能度PAE-a扩链的聚脲。软段分子量较高的聚脲向于微相分离。室温成型的聚脲为半相容结构,成型温度提高至60℃时,呈现微相分离结构。

Several polyaspartic esters （PAE） based polyureas were prepared from synthesized PAE and hexamethylene diisocyanate（HDI） trimer/polytetramethylene ether glycol （PTMG） prepolymer. The dynamic mechanical analysis （DMA） was used to reasearch the effect of PAE structure, length of soft segments and curing temperatures on the morphology and mechanical properties of these polyureas. The results indicated that the polyurea exhibits larger storage modulns（E＇ ）, higher glass transi- tion temperature of hard segment（Tgh）, and higher level of microphase separation when three degree of functional PAE-F was used as chain extender instead of two degree of functional PAE-a. Polyurea contenting longer soft segment exhibits a higher level of microphase separation. While curing at room temperature, the polyurea was related with a half compatibility morphology, while curing at 60 ℃ it was related with better microphase separated morphology.