Improvement of Poly(Vinyl Alcohol) Adhesives With Cellulose Microfibre from Sugarcane Bagasse

The properties of eco-friendly adhesives prepared from poly(vinyl alcohol) (PVOH) can be improved by the use of cellulose microfibre (CMF). The CMF was prepared from oven dried sugarcane bagasse fibres. They were hydrolyzed with nitric acid of 10% (w/w). The cellulose content of the CMF increased from 44.10% to 88.99% after treatment. The CMF was added into PVOH adhesives in varied amounts of 0.5, 1.5, 2.5 and 3.5 wt% of total dry adhesive weight. The effects of CMF on chemical structure, thermal properties and crystallinity of the composite adhesives were investigated by Fourier-transform infrared spectroscopy and differential scanning calorimetry. The results showed the interactions of OH groups of PVOH with CMF molecular chains which led to increased melting point and crystallinity. In addition, the molecular weight and concentration of PVOH influenced the adhesion property of the composite adhesives. The results indicated that with the addition of CMF filler the shear strength of samples of PVOH (BF-17) of medium molecular weight increased from 1.55 to 2.41 MPa, while those of high molecular weight (BF-26) increased from 1.79 to 2.15 MPa. Furthermore, the incorporation of the CMF into the PVOH adhesives led to an improved drying time during adhesion of the test specimens.