Abstract

In this study we prepared the novel compound L-isoleucine-phthalandione (LIPTA), featuring carboxyl and amide groups, and its calcium salt, the calcium salt of L-isoleucine-phthalate (LIPTA-Ca), and characterized them using ¹H nuclear magnetic resonance spectroscopy, thermogravimetric analysis, and differential scanning calorimetry (DSC). LIPTA-Ca has a relatively high melting point and thermostability. We employed DSC and polarized optical microscopy and tests of mechanical properties to examine the effect of LIPTA-Ca on the crystallization behavior and mechanical properties of isotactic polypropylene (iPP). We found that LIPTA-Ca is a highly effective α-nucleating agent that can increase the crystallization temperature of iPP by more than 10 °C during cooling, when present as an additive at a content of 0.15 wt%, while greatly decreasing the spherulite size and accelerating the crystallization rate of iPP. In addition, LIPTA-Ca can improve the rigidity of iPP significantly without decreasing its toughness.

摘要

在这项研究中，我们制备了具有羧基和酰胺基团的新型化合物 L-异亮氨酸-邻苯二甲酸 (LIPTA) 及其钙盐，L-异亮氨酸-邻苯二甲酸钙盐 (LIPTA-Ca)，并使用¹H 核磁共振波谱、热重分析和差示扫描量热法 (DSC)。LIPTA-Ca 具有相对较高的熔点和热稳定性。我们采用 DSC 和偏光显微镜以及机械性能测试来检查 LIPTA-Ca 对等规聚丙烯 (iPP) 结晶行为和机械性能的影响。我们发现 LIPTA-Ca 是一种高效的 α-成核剂，当作为添加剂以 0.15 wt% 的含量存在时，它可以在冷却过程中将 iPP 的结晶温度提高 10 °C 以上，同时大大降低球晶尺寸并加快iPP的结晶速度。此外，LIPTA-Ca可以在不降低韧性的情况下显着提高iPP的刚性。