Effect of cellulose size-concentration on the structure of polyvinyl alcohol hydrogels

[Display omitted] •Both size and concentration of cellulose fibrils affects the hydrogel structure.•At higher cellulose concentration, chain entanglement and structure are modified.•Microfibrillated cellulose loaded onto PVA hydrogels have a slower kinetic release.•Cellulose drastically increases the mechanical properties of PVA dried hydrogels. Microfibrillated cellulose as a reinforcement agent has been investigated extensively due to their unique characteristics, which can reorder the structure of polymers and hydrogels leading to improved mechanical properties with minimal disadvantages in terms of the targeted original applications. However, effect of using a macro- to a micro-fibrillated cellulose onto polyvinyl alcohol hydrogels is still unknown, because of the unique ability for both to be produced as hydrogels from freeze-thawing mechanisms – hydrogen bonding - there is a potential synergism. Therefore, macro and microfibrillated kraft bleached paper was synthesised at various concentrations on polyvinyl alcohol hydrogels. The overall effect presented a strong interaction between both compounds but it was increased with macrofibrillated cellulose. Increase in crystallinity was also observed with a macro-sized fibre without variation on tensile elastic modulus but an overall improvement was perceived on thermal properties and a slower swelling rate with a microfibrillated cellulose.