A review on lignocellulose/poly (vinyl alcohol) composites: cleaner approaches for greener materials

Lignocellulose (LC) is an abundant resource in nature often neglected, underutilised, and even disposed of with an extra cost. Though extracting cellulose or starch from LC is very common for materials production, the use of complete LC has a cleaner prospect as fewer purification treatments are required, and more residues are eliminated in the process. However, to transform LC into a required shape, synthetic polymers are often required to perform as a matrix by holding the LC particles together. In this regard, poly (vinyl alcohol) (PVA) is a great choice due to its reasonable cost, commercial availability and probably its biodegradation. Although the biodegradation of PVA is controversial, currently there is a large amount of encouraging evidence on its natural degradation. In recent years, several LC/PVA studies have shown promise in producing plastic films, sheets, sticks, nanofibres and hydrogel. Taking account of the greener and cleaner aspect of the LC/PVA combination, this review comprehensively evaluates the morphological, mechanical, thermal, crystalline, moisture, optical, antimicrobial, antioxidant and biodegradation properties of the reported composites in relation to the chemical structure of LC and PVA. In addition, the advantages and challenges of LC/PVA composites are discussed and future opportunities are explored.