Abstract
This work proposes a new approach to fabricate highly transparent and flexible composite films that exhibit enhanced UV-shielding properties. Lignin has innate UV-shielding properties. However, when purified lignin, which is conventionally extracted through chemical treatment, is mixed with polymeric materials, its presence negatively influences the transparency of the resulting composite. High transparency and UV-shielding are desirable properties for many applications. In this study, composites were made by mixing lignocellulose particles and polyvinyl alcohol (PVA), where lignocellulose particles were obtained from ball-milled waste hemp hurd without chemical treatments. The UV-shielding properties of the resulting composite film, as a function of hemp/PVA weight ratios, were investigated. The intermolecular interactions between the hemp particles and the PVA were characterized using infrared spectroscopy with the presence of –C=O group at 1655 cm−1, providing evidence that the chemical structure of lignin was preserved. The fabricated hemp/PVA films exhibit stronger UV-shielding, in the UVA-I range (340–400 nm) than TiO2/PVA films. The composite films also showed comparable water vapor permeability (WVP) with commercial packaging plastic film made of HDPE (high-density polyethylene). The optimization experiments were reported, with aim at understanding the balance between the UV-shielding and mechanical properties of the hemp/PVA films. The findings of this work can be applicable to the packaging, food and cosmetic industries where UV shielding is of utmost importance, hence adding value to hemp hurd waste.
Highlights
Long-term exposure to ultraviolet radiation causes severe damage to animals, plants and to some materials [1]
The findings of this work can be applicable to the packaging, food and cosmetic industries where UV shielding is of utmost importance, adding value to hemp hurd waste
%film; film; Figure (b) Transmission spectra of the composite composite films films with with various various hemp hemp hurd hurd additions additions in in this this study study and and (b)
Summary
Long-term exposure to ultraviolet radiation causes severe damage to animals, plants and to some materials [1]. UV shielding research has focused mainly on the role of inorganic metal oxides such as titanium dioxide (TiO2 ), zinc dioxide (ZnO) and silicon dioxide (SiO2 ) [2,3,4]. Inorganic metal oxides exhibit good UV-shielding, their synthesis and disposal methods may have some environmental and health concerns [5]. Lignin has innate UV-shielding properties and it has been proposed as a substitute for inorganic metal oxides [7]. Use of lignin as a UV-shielding additive may reduce the environmental and health impacts of inorganic metal oxides [5]. Research work on the UV shielding properties of lignin has been focused on understanding the influence of its size [8], chemical modifications [1] and its sourcing [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
