马来酸单聚乙二醇单甲醚酯等温结晶行为研究

Study on Isothermal Crystallization Behavior of MPEGMA

采用偏光显微镜（POM）和差示扫描量热仪（DSC）观察了马来酸单聚乙二醇单甲醚酯（MPEGMA）的结晶形态,并对其结晶动力学进行了研究。结果表明：随着等温结晶温度的升高,MPEGMA结晶中的束状结构逐渐消失,球晶生长速率呈非线性下降;随着等温结晶时间的延长,MPEGMA的球晶半径呈线性增加。MPEGMA的等温结晶动力学分析结果显示,其Avrami指数为1.84~2.16,结晶活化能为136.3 k J/mol。Avrami指数的数据表明MPEGMA晶体呈二维生长模式,成核方式为均相成核。

The crystal morphology and melt crystallization kinetics of mono polyethylene glycol maleate （MPEGMA） were investigated by means of polarizing microscope （POM） and differential scanning calorimeter （DSC）. The results show that the sheaflike structure in MPEGMA crystals disappears gradually, and the growth rate of MPEGMA spherulites nonlinearly decreases as the isothermal crystallization temperature increases. The radius of MPEGMA spherulites increases linearly with the increase of isothermal crystallization time. The isothermal crystallization kinetics of MPEGMA indicates that the Avrami exponent changes in the range from 1.84 to 2.16 and crystallization activation energy is 136.3 kJ/mol The data of Avrami exponent shows that the crystallization mechanism of MPEGMA belongs to homogeneous nucleation with dimensional growth.