Multiple shape memory polymers based on laminates formed from thiol-click chemistry based polymerizations

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Shape memory polymers (SMPs) offer transformative potential in various fields.
• Developing multi-responsive SMPs with tunable properties remains a key challenge.
• Advanced fabrication techniques are needed for complex SMP architectures.

Purpose of the Study:

• To fabricate polymer network trilayer laminates using thiol-X click chemistries.
• To evaluate the quadruple shape memory behavior of these laminates.
• To investigate the role of interfacial properties on material performance.

Main Methods:

• Utilized thiol-Michael addition and thiol-isocyanate reactions for layer fabrication.
• Achieved independent control over each layer's chemistry and properties.
• Employed step-growth thiol-X reactions for network uniformity and narrow thermal transitions.

Main Results:

• Successfully fabricated trilayer laminates with three distinct glass transition temperatures within a 100 °C range.
• Demonstrated a step-wise modulus drop by varying layer thicknesses, enabling multi-step programming.
• Quantified quadruple shape memory performance and confirmed strong interfacial binding with no delamination during cyclic testing.

Conclusions:

• Thiol-X click chemistries provide precise control for fabricating advanced polymer laminates.
• The developed trilayer system exhibits robust quadruple shape memory behavior.
• Strong interlayer adhesion is crucial for the stability and performance of these multi-functional materials.