How Depolymerization-Based Plasticization Affects the Process of Cold Crystallization in Poly(P-Dioxanone)

Area of Science:

• Polymer Science
• Materials Science
• Crystallization Studies

Background:

• Self-plasticization, an increase in polymer chain mobility via monomer inclusion, affects polymer properties.
• Poly-(p-dioxanone) (PDX) is a polymer whose structural, thermal, and mechanical characteristics can be influenced by self-plasticization.

Purpose of the Study:

• To investigate the impact of thermally induced self-plasticization on poly-(p-dioxanone) crystallization.
• To analyze changes in crystal growth from amorphous and molten states due to self-plasticization.

Main Methods:

• Differential Scanning Calorimetry (DSC)
• Optical and Raman Microscopies
• Thermo-Mechanical Analysis (TMA)
• Size Exclusion Chromatography with Multi-Angle Light Scattering (SEC-MALS)
• X-ray Diffraction Analysis (XRD)

Main Results:

• Significant changes in PDX crystallization and mechanical properties observed above 150°C (depolymerization temperature).
• Intense self-plasticization decreased crystallization temperature, increased crystal growth rate, eliminated polymorphic transition, and lowered melting temperature.
• Self-plasticization did not significantly alter crystallite magnitude, localization, or morphology, which were primarily governed by crystal growth temperature.

Conclusions:

• Thermally induced self-plasticization above 150°C profoundly affects PDX crystallization behavior and thermal properties.
• The study discusses the manifestation of the variable activation energy concept in the observed crystallization data.