Room-Temperature Self-Healing, High Ductility, Recyclable Polyurethane Elastomer Fabricated Via Asymmetric Dynamic Hard Segments Strategy Combined with Self-Cleaning Function Application

Abstract

Constructing room-temperature self-healing materials which overcome the trade-off between material self-healing and mechanical properties is challenging. This study introduces the concept of “asymmetric dynamic hard segments” to balance mechanical strength and self-healing properties while ensuring high ductility and recyclability. The introduction of the asymmetric dynamic hard segments allows the polymer chains to have an amorphous structure and high mobility and enables dissociation and rapid recombination of multiphase hydrogen bonds. Based on this feature, a simple two-step polycondensation reaction is reported for synthesizing a room-temperature-self-healing polyurethane elastomer (PPG-IH-IPDA) with good mechanical strength, good toughness, high ductility and excellent recyclability. Experimental results show that room-temperature self-healing can completely eliminate scratches on PPG-IH-IPDA, and the mechanical properties of the elastomer are totally restored. With the advantageous characteristics of PPG-IH-IPDA, the perfect combination of self-healing and self-cleaning functions leads to the preparation of a superhydrophobic composite material (SHN-SiO 2 /PPG-IH-IPDA) that shows a contact angle greater than 150°, which enables surface damage self-healing at room temperature. Such combination of self-healing and self-cleaning properties provides substantial guidance for the development of versatile materials.

Keywords: asymmetric dynamic hard segments, self-healing, self-cleaning, multi function combination