Hydroxypropyl methylcellulose films reinforced with cellulose micro/nanofibrils: study of physical, optical, surface, barrier and mechanical properties Valorization cellulosic materials for films production

The accumulation of petroleum products causes damage to ecosystems, which can be avoided with cellulose-based products. The influence of different ratios of cellulose micro/nanofibrils (MFC/NFC) on the properties of hydroxypropyl methylcellulose (HPMC) films was evaluated. Films were prepared using proportions of 0, 25, 50, 75 and 100 % (w/w) of MFC/NFC from Pinus sp. in relation to HPMC. Physical, barrier, surface, optical, morphological and mechanical properties were evaluated. Solids content, basis weight and density values increased with higher amount of MFC/NFC and thickness and porosity were reduced. SEM images showed that films with more than 50 % MFC/NFC had a more granular surface, which decreased transparency from 80 to 65 %. Water vapor penetration did not differ between films and degradation in water was reduced from 40 to 5 % with MFC/NFC addition. There were no differences in contact angle and wettability, but all films showed high resistance to fat penetration. Films with MFC/NFC content between 75 and 100 % showed higher values for tensile strength (50 to 65 MPa) and Young's modulus (6 to 10 MPa) and lower elongation at break (1 to 2 %). The experimental results indicated that films with MFC/NFC content above 50 % have potential to be used as packaging material.