Achieving PLA with Excellent Heat Resistance and Transparency via Synergistic Nucleation Effect Assisted by Hydrogen...

Area of Science:

• Polymer Science and Engineering
• Materials Chemistry
• Crystallization Kinetics

Background:

• Poly(l-lactic acid) (PLA) requires effective nucleating agents (NAs) for enhanced heat resistance and transparency.
• Traditional self-assembling NAs for PLA demand long processing times due to slow network formation during cooling.
• This limitation restricts PLA's crystallization window, necessitating high temperatures and extended annealing periods.

Purpose of the Study:

• To develop a synergistic nucleation strategy for accelerating PLA crystallization.
• To overcome the limitations of slow self-assembly of NAs in rapid cooling processes.
• To improve the thermal and mechanical properties of PLA through faster induced crystallization.

Main Methods:

• Utilized hexanedioic,1,6-bis (2-benzoyl hydrazide) (TMC) to induce self-assembly of N,N-ethylenebis(12-hydroxystearamide) (EBH) nanofibers via hydrogen bonding.
• Promoted PLA crystallization using the nucleating effect of the pre-formed EBH nanofibrous network.
• Investigated the effect of the synergistic nucleation on PLA crystallinity, crystal morphology, and annealing time.

Main Results:

• Achieved earlier induction of PLA crystals during rapid cooling, leading to higher crystallinity and smaller crystal sizes.
• Significantly reduced annealing time at 85 °C to 90 seconds.
• Enhanced heat deflection temperature (HDT) to 96.6 °C, increased light transmission at 600 nm from 21% to 70%, and improved impact strength from 3.2 to 7.8 kJ/m².

Conclusions:

• The synergistic nucleation strategy effectively accelerates PLA crystallization kinetics.
• This method provides a universal approach for rapid NA self-assembly in PLA processing.
• The enhanced properties broaden the application potential of PLA-based materials.