Double-network hydrogels with superior self-healing properties using starch reinforcing strategy

• Published in: Carbohydrate polymers 2021-04, Vol.257, p.117626-117626, Article 117626
• Main Authors: Shang, Xiaoqin, Wang, Qingling, Li, Jinghao, Zhang, Guojie, Zhang, Jianguo, Liu, Peng, Wang, Liming
• Format: Article
• Language: English
• Subjects: Double-network; Mechanical properties; Self-healing; Starch
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2021.117626

A starch reinforced strategy brings in superior self-healing property as well as remarkably enhanced mechanical strength to polymer hydrogels. [Display omitted] •A hybrid DN hydrogel with enhance properties is prepared with a starch reinforcing tactic.•Starch significantly enhances both the mechanical and self-healing properties of gels.•Starch gelatinization and solvent soaking treatment play important roles in behaviors of the gels.•The composite gel shows rapid self-recovery and excellent fatigue resistance.•The DN gel shows superior healing efficiencies (up to 99 % after 24 h of healing). Constructing hybrid double network (DN) hydrogels has become an important strategy to prepare strong and tough hydrogels with good self-healing properties for durable usage. However, the recoverable and self-healing efficiencies of DN hydrogels are usually low. We develop a type of hybrid DN hydrogel, which contain the starch network for generating strong dynamic interactions within the gel matrix. The composite gels show tensile strength over 200 kPa with the elastic modulus of ∼29.7 kPa. Gelatinization of cassava starch is a key procedure that can significantly raise mechanical strengths. The healing efficiency of the composite gel gradually increased to as high as 99 % after 24 h at room temperature. This work shows that dynamic physical bonding in hydrogels can be greatly enhanced by a simple starch reinforcing tactic. The combination of naturally abundant starch with hydrophilic polymers provides a general approach to design functional soft materials for applications in various fields.