Journal
MECHANICS OF MATERIALS
Volume 156, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.mechmat.2021.103785
Keywords
-
Categories
Funding
- National Natural Science Foundation of China [11972011, 11702248]
- Major Program of National Natural Science Foundation of China [11932007]
- Opening Project of Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province [SZDKF-201901]
- Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices [2019B121203003]
- Recruitment Program of Guangdong [2016ZT06C322]
- Program for Guangdong Introducing Innovative and Entrepreneurial Teams, China [2019ZT08Y318]
Ask authors/readers for more resources
The study investigated the tensile and fracture behavior of physically and chemically crosslinked HA/chitosan hydrogels at different stretch velocities. It was found that the fracture energy of highly chemically crosslinked hydrogels scales with the crack velocity as a power law relation, while the fracture energy of physically and lightly chemically crosslinked hydrogels increases with the crack velocity as a complex growth function. This indicates that the viscoelastic energy dissipation around the crack tip dominates the fracture energy of highly chemically crosslinked hydrogels, while the fracture energy of physically and lightly chemically crosslinked hydrogels is dominated by the unzipping of the polyion complex structure and viscous energy dissipation.
Tough bio-based hydrogels based on the association of physical bonds are promising materials for use in biomedical applications due to their biocompatibility, biomimicry and biodegradability. Understanding the mechanical mechanisms at work during the fracture in such applications is indispensable. Using tough and self-healing bio-based hydrogels attained by the complexation of the negatively charged sodium hyaluronate (HA) and positively charged chitosan as a model system, an investigation of the tensile and fracture behavior over five decades of stretch velocities in physically and chemically crosslinked HA/chitosan hydrogels was systematically performed. In this study, the tensile analysis shows that the both of physically and chemically crosslinked hydrogels at small deformation are viscoelastic at a low stretch velocity, while they exhibit quasi-elastic character at a relatively high stretch velocity. In comparison to the physically and lightly chemically crosslinked HA/chitosan hydrogels exhibiting plastic-like behavior, the highly chemically crosslinked hydrogels demonstrate strong finite chain extensibility before fracture. The fracture analysis shows that the fracture energy of the highly chemically crosslinked hydrogels scales with the crack velocity as a power law relation Gamma infinity V-c(a) (a= 0.15), where the exponent a can be well predicted from the viscoelastic spectrum of the bulk sample. These findings indicate that the viscoelastic energy dissipation around the crack tip dominates the fracture energy of the highly chemically crosslinked hydrogels. On the other hand, the fracture energy of the physically and lightly chemically crosslinked hydrogels is noted to increase with the crack velocity as a complex growth function, which can be effectively predicated by a viscoplastic model. The observed finding shows that the fracture energy of the physically and lightly chemically crosslinked hydrogel is dominated by the unzipping of the polyion complex structure and viscous energy dissipation due to the pulled out chains from the polymer network structure.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available