Fabrication of Crosslinked Poly(L-lactic acid) with Enhanced Shape Memory Performance via γ-Ray Irradiation

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Poly(L-lactic acid) (PLLA) based shape memory polymers (SMPs) possess intrinsic limitations hindering their performance.
• Achieving high shape recovery ratios and stable cycling performance in PLLA SMPs remains a challenge.
• Developing advanced SMPs with multiple shape memory capabilities is an active area of research.

Purpose of the Study:

• To overcome the intrinsic limitations of PLLA-based SMPs.
• To develop PLLA SMPs with enhanced shape memory properties and triple-shape memory performance.
• To investigate the effect of γ-ray-induced crosslinking on PLLA/triallyl isocyanurate (TAIC) blends.

Main Methods:

• Fabrication of miscible PLLA/triallyl isocyanurate (TAIC) blends.
• Introduction of γ-ray-induced crosslinking to the PLLA/TAIC blends.
• Precise adjustment of crosslinking density via TAIC content and absorbed irradiation dose.

Main Results:

• Achieved outstanding shape memory properties in crosslinked PLLA SMPs.
• Demonstrated a high shape recovery ratio (99.5%) and excellent cycle stability (97.9% after three cycles).
• Exhibited triple-shape memory performance utilizing both glass transition and melting temperatures as switch conditions.
• Maintained a high recovery ratio (99.3%) even under extreme deformation (800% strain).

Conclusions:

• γ-ray-induced crosslinking effectively suppresses cold crystallization and prevents irreversible chain slippage in PLLA SMPs.
• The crosslinking strategy provides a novel approach for fabricating high-performance PLLA SMPs with exceptional shape recovery.
• The developed PLLA SMPs exhibit promising potential for advanced applications requiring superior shape memory capabilities.