Temperature Effects on the Crystalline Structure of iPP Containing Different Solvent-Treated TMB-5 Nucleating Agents.

TMB-5 nucleating agent (NA) treated by different solvents were used as the β -NA of iPP. The effects of temperature on the crystalline structure of different iPP/TMB-5, as well as the crystallization and melting behaviors were investigated. It was found that strong polar solvent treated TMB-5 (TMB-5 DMSO and TMB-5 DMF ) could induce more β -crystal at high T c = 140 °C than the other TMB-5 NAs, while the β -crystal inducing efficiency of untreated TMB-5 (TMB-5 UT ) and non-polar solvent treated TMB-5 (TMB-5 LP ) is seriously reduced at high T c = 140 °C. TMB-5 DMSO can induce a high and stable content of β -crystal with K β = 83-94% within T c = 90-140 °C, and TMB-5 ODCB can induce a high content of β -crystal with K β > 91.3% within T c = 90-130 °C. TMB-5 DMF is the most temperature-sensitive one, but can induce a high fraction of β -crystal with K β > 92% both at low T c = 90 °C and high T c = 140 °C. High temperature pre-crystallization at T pc = 150 °C tremendously reduces the β -crystal inducing efficiency of all TMB-5 NAs. TMB-5 UT and TMB-5 LP exhibit higher nucleating efficiency than TMB-5 DMSO , TMB-5 DMF and TMB-5 ODCB . During the non-isothermal crystallization process, TMB-5 UT induced β -crystal possesses higher structural perfection and stability, while TMB-5 LP is more likely to induce α -crystal with considerable quantity and stability. The structural perfection and stability of TMB-5 induced β -crystal can be enhanced with appropriate increasing of T c .