Today's KNOWLEDGE Share : VITRIMERS:

Today's KNOWLEDGE Share

VITRIMERS:

Vitrimers is a relatively new term for a class of polymers that have existed for decades. These classes of polymers are special as they have properties of both thermosets and thermoplastics. Traditionally, thermoplastics can be recycled and reworked. Thermosets are generally known to not undergo any further reactions and chemical changes once they are formed and crosslinked.

Vitrimers have crosslinked structures like thermosets but they can be recycled like thermoplastics. This is made possible because of bond exchange reactions. These bond exchange reactions happen even in the solid state so the thermoset polymer has a mechanism of plasticity and adhesive bonding even in the solid-state.

The first vitrimer polymer was developed by James Economy’s group at UIUC in the 1990’s.The research demonstrated a new class of thermoset polymer systems that were processable by virtue of topology changes within the covalent networks as mediated by bond exchange reactions.This class of polymers was called aromatic thermosetting copolyester. It was shown composite laminae could be consolidated to make a dense composite structure.The Economy group conducted studies employing secondary ion mass spectrometry (SIMS) on deuterated and nondeuterated fully cured vitrimer layers to discriminate the length scales (<50 nm) for physical interdiffusion between vitrimers constituent atoms providing evidence towards eliminating physical interdiffusion of the polymer chains as the governing mechanism for bonding between vitrimer layers.

The term vitrimer came after two decades of this work and it has drawn interest to this new field of polymers.Vitrimers were first termed as such in the early 2010s by French researcher Ludwik Leibler, from CNRS. Leibler and co-workers developed silica-like networks using the wellestablished transesterification reaction of epoxy and fatty dicarboxylic or tricarboxylic acids. Besides epoxy resins, other polymer networks have been used to produce vitrimers, such as aromatic polyesters, polylactic acid (polylactide),polyhydroxyurethanes,epoxidized soybean oil with citric acid and polybutadiene.

Healthcare:

The integration of Smart materials is transforming the healthcare industry by addressing long-standing challenges. Consider the possibilities of prosthetic limbs that dynamically adjust their shape to match various objects,providing amputees with a natural and adaptive grip. With the strategic incorporation of vitrimers, prosthetic technologies are advancing, enabling wearers to regain functionality and enhance their quality of life.

Smart plastics are driving innovation in the development of smart bandages that intelligently adapt to changes in wound conditions.These bandages leverage their shapeshifting properties to optimize healing and prevent infections by releasing targeted medications/adjusting their shape to suit the wound environment.

Source:ATSP INNOVATIONS/ACSPublications/Mallinda/Smart Mater