Cross-linked nanocomposite hydrogels based on cellulose nanocrystals and PVA: Mechanical properties and creep recovery

Abstract

Cellulose nanocrystal (CNC) reinforced poly(vinyl alcohol) (PVA) hydrogels with a water content of ~92% were successfully prepared with glutaraldehyde (GA) as a cross-linker. The effects of the CNC content on the thermal stability, swelling ratio and mechanical and viscoelastic properties of the cross-linked hydrogels were investigated. The compressive strength at 60% strain for the hydrogels with 1 wt% CNCs increased by 303%, from 17.5 kPa to 53 kPa. The creep results showed that the addition of CNCs decreased the creep elasticity due to molecular chain restriction. The almost complete strain recovery (~97%) after fixed load removal for 15 min was observed from the hydrogels with CNCs, compared with 92% strain recovery of the neat cross-linked PVA hydrogels. The incorporation of CNCs did not affect the swelling ratio and thermal stability of the hydrogels. These results suggest the cross-linked CNC-PVA hydrogels have potential for use in biomedical and tissue engineering applications.

Crosslinked poly(vinyl alcohol) composite films with cellulose nanocrystals: Mechanical and thermal properties

“…TGA thermograms of nPVA, XPVA, and CNCs are presented in Figure (a). The nPVA thermogram shows three main thermal degradation transition stages, similar to other observations . The initial transition region is found up to 100 °C and is due to water evaporation.…”

“…After the load removal, the strain of the crosslinked PVA films with CNCs immediately decreased to ∼0.03%, and completely returned to their original state after 40 min of relaxation time. The results imply that the crosslinked PVA films show a high degree of crosslinking . Conversely, the PVA sample required a longer time to reach the original shape after the load removal.…”

“…The decrease of the decomposition temperature could also be found when the degradation temperature of CNCs is much lower than that of the matrix. For example, CNC/PVA hydrogels crosslinked with glutaraldehyde were prepared . With 2 wt % of CNCs, the degradation temperature of the crosslinked hydrogel decreased significantly to 320 °C, compared to the degradation temperature of 347 °C for the crosslinked PVA hydrogel without CNCs.…”

Polylactic acid/polyurethane blend reinforced with cellulose nanocrystals with semi-interpenetrating polymer network (S-IPN) structure

“…IPNs and SIPNs were one of the key classes of polymeric materials in the late 1960s and 1970s, and a major part of the research was conducted in that era. Lately, IPN and SIPN hybrid materials have been used especially for biomedical applications [9][10][11]. By definition, IPNs comprise an interwoven matrix of two chemically distinct polymers that are intimately mixed with each other with nominal bonding and that are both present as a continuous phase.…”

Preparation and properties of a poly(vinyl alcohol) hydrogel‐melamine formaldehyde foam composite

“…Poly(vinyl alcohol) (PVA) is a well‐known synthetic polymer widely applied in industries due to its desirable properties including nontoxicity, good biocompatibility, excellent mechanical properties, water solubility, biodegradability, and relatively low cost . Particularly, PVA hydrogel materials constructed by a three‐dimensional polymer network and large quantity of water have attracted much attention in the field of the biological treatment of wastewater in the last decades .…”