Mechanical, thermal, and barrier properties of PHBH/cellulose biocomposite films prepared by the solution casting method

Abstract

A biocomposite film from bacterial polyester, poly(3- hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), and natural cellulose was developed by the solution casting method. The structure, the mechanical, thermal, and barrier properties (oxygen and water vapor), and the biodegradation of the PHBH/cellulose biocomposite films were studied. With an increase in cellulose content, the tensile strength of biocomposite films increased from 28.5 MPa to 45.9 MPa, an improvement of 351% compared with neat PHBH. The PHBH/cellulose biocomposite films exhibited improved thermal stability, with the maximum thermal decomposition temperature increased from 264 °C to 330 °C. More importantly, PHBH/cellulose biocomposite films possessed better barrier properties against oxygen, up to approximately 10 times more than neat PHBH. With cellulose content increased from 50 wt% to 90 wt%, the mass loss of composite films increased gradually and then decreased. This high performance biocomposite has potential to expand the use of cellulose from renewable bioresources and the practical application of PHBH-based biodegradable plastics instead of traditional petrochemical materials in the packaging field.