Effect of final heating temperature on crystallization of isotactic polypropylene nucleated with an aryl amide derivative as β-form nucleating agent
(308-317)  Chinese Journal of Polymer Science 29, #3 (2011)
Dong et al of Tsinghua University, Chinastudied the effect of heating on an aryl dicarboxylic acid amide compound TMB-5, an efficient β-form nucleating agent for isotactic polypropylene (iPP). Because of the solubility of TMB-5, superstructure and morphology of iPP crystals changed with melting conditions.  It was discovered that the crystallization temperature increased with decreasing T f value. The optical microscopic images indicated that when TMB-5 partially dissolved in iPP melt, the remaining (non-dissolved) TMB-5 facilitated the recrystallization of dissolved nucleating agent from the melt, which promoted crystallization. Complete solubility of nucleating agent caused the decreasing efficiency. TMB-5 recrystallized in the form of tiny needles, whose aggregates induced dendritic iPP crystals.  (RDC 5/16/2011)