Preparation and Characterization of Poly (3-hydroxybutyrate-co-4-hydroxybutyrate)/Porous Cellulose Aerogel Biocomposites

A green biocomposite of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) and cellulose aerogels was developed. Cellulose gel was prepared from NaOH/urea aqueous solution, and subsequent regenerating by Na2SO4 solution and freeze-drying resulted in porous cellulose aerogels. The P34HB/cellulose aerogel biocomposite was fabricated by immersion of porous cellulose in a polymer solution and hot-pressing. The morphology, crystallization, thermal, mechanical, and barrier properties (H2O) of biocomposite were investigated. The cellulose aerogels matrix exhibited a three-dimensional network structure with porosity and a wide pore size distribution, contributing to the change of the glass transition temperature and cold crystallization temperature of biocomposites. Compared with cellulose aerogels, the tensile strength and elongation at break of biocomposites were increased by as much as 48% and 25.1%, respectively. Moreover, biocomposites demonstrated an increased contact angle and water vapor permeability coefficient compared with the cellulose aerogel. The results revealed the potential of P34HB/cellulose aerogel biocomposites for practical application as packaging materials.