Stiffening and Toughening Rigid Polymers Through Controllable Stress Concertation Induced by Hard-Hard Dual...

Area of Science:

• Polymer Science
• Materials Science
• Nanotechnology

Background:

• Rigid polymers often exhibit a trade-off between rigidity and extensibility.
• Achieving both high rigidity and extensibility in polymers like poly(lactic acid) (PLA) is challenging due to conflicting molecular requirements.

Purpose of the Study:

• To overcome the rigidity-extensibility trade-off in rigid poly(lactic acid) (PLA).
• To enhance both the rigidity and extensibility of PLA through a novel nanophase strategy.

Main Methods:

• Fabrication of dual nanophases using a masterbatch method and low-temperature annealing.
• Incorporation of nanodispersed carbon nanotubes (CNTs) and nanoscale PLA crystals as hard-hard dual nanophases.
• Characterization of mechanical properties, including Young's modulus, elongation at break, and toughness.

Main Results:

• Achieved unprecedented improvements in PLA's rigidity (32% increase in Young's modulus) and extensibility (644% increase in elongation at break).
• Enhanced toughness by 776% through a toughening mechanism involving controlled microcrack initiation and suppression.
• Demonstrated improved heat resistance and electrical conductivity in the dual-nanophase PLA.

Conclusions:

• The hard-hard dual nanophase strategy effectively overcomes the rigidity-extensibility trade-off in rigid polymers.
• This approach offers a promising pathway for developing high-performance polymers with superior comprehensive properties.
• The findings contribute to polymer toughening theory and industrial applications.