Room-Temperature Self-Healing Polyurethanes Containing Halloysite Clay with Enhanced Mechanical Properties

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Room-temperature self-healing polyurethanes (PUs) often have limited mechanical strength.
• Improving mechanical properties without compromising self-healing is a key challenge.

Purpose of the Study:

• To enhance the mechanical properties of intrinsically self-healing polyurethanes.
• To investigate the effect of halloysite clay filler on PU performance.
• To maintain room-temperature self-healing capabilities.

Main Methods:

• Synthesized polyurethanes using polycarbonate diol, aliphatic diisocyanate, and 1,4-butanediol.
• Incorporated varying amounts (0.5-10 wt.%) of thermally treated halloysite clay into the polyol during synthesis.
• Evaluated structural, thermal, viscoelastic, and mechanical properties of the halloysite-filled PUs.

Main Results:

• All halloysite-filled PUs retained room-temperature self-healing ability.
• The PU with 0.5 wt.% halloysite (E0.5) exhibited the best balance of properties, with well-dispersed nanotubes enhancing chain mobility.
• Increased halloysite content beyond 0.5 wt.% led to agglomeration and limited improvements, with no further gains above 3 wt.%.

Conclusions:

• Halloysite clay can effectively enhance mechanical properties of self-healing polyurethanes.
• Optimal filler loading is crucial for maximizing benefits and avoiding negative effects like agglomeration.
• This research provides insights into filler-polymer interactions for designing advanced multifunctional PUs.