Abstract: This work presents the effect of di(3，4-dimethyl) dihenzaldchyde sorhitol (DMDBS) on the crystallization behavior of polypropylene (PP).The contents of DMDBS in PP were 0.1%，0.3%，0 .5%，0.7%，and 0.J%.Various techniques including FT-IR, DSC, WAXD, polarized light microscopy, etc. were employed to investigate crystal structures and thermal properties for the samples.
Extensive experiments demonstrated that DMDBS acted as an effective a form nucleating agent for PP，resulting in smaller spherulite size, higher crystallization and melting temperatures, and higher trans-parency of the samples.

Key words: di(3, 4-dimethyl) dihenzaldchyde sorhitol, polypropylene, nucleating agent, crystal morphology