Crystallization Behavior of Isotactic Polybutene Blended with Polyethylene

Area of Science:

• Polymer Science
• Materials Science
• Crystallization

Background:

• Polybutene (PB) exhibits complex melt crystallization and solid-phase transitions.
• Understanding these behaviors is crucial for tailoring PB-based material properties.

Purpose of the Study:

• To investigate the melt crystallization and solid-phase transition of isotactic polybutene (PB) in blends with high-density polyethylene (PE).
• To elucidate the effect of PE composition on PB's polymorphic behavior and transition kinetics.

Main Methods:

• Dynamic cooling crystallization experiments.
• Ex situ X-ray diffraction (XRD) and in situ Fourier transform infrared spectroscopy (FTIR).
• Isothermal crystallization studies at varying temperatures.

Main Results:

• PE addition influences PB crystallization temperature non-monotonically.
• High PE content (≥70 wt%) induces direct formation of PB's trigonal form I' from the melt.
• PB/PE blends with ≥70 wt% PE show accelerated phase transition from form II to form I at room temperature.

Conclusions:

• High-density polyethylene significantly modifies polybutene's crystallization pathways and solid-state phase transitions.
• The composition and temperature play critical roles in controlling PB's polymorphic outcomes in PB/PE blends.
• Blends with substantial PE content offer enhanced control over PB phase transitions.