Tannic acid: An interesting natural filler for HDPE
Topic(s) : Material science
Co-authors :
Alexandra ZAMBOULIS (GREECE), Samiotaki CHRISTINA (GREECE), Myrto TARA , Evangelia TARANI (GREECE), Konstantinos CHRISAFIS , Dimitrios BIKIARISAbstract :
Due to the environmental crisis experienced by our modern societies in the 21st, alternatives to the liner model of production and consumption established in the 20th century. One of the most popular approaches to improve the sustainability of our products and reduce their environment footprint, is the valorisation of renewable resources, which in turn will allow the lower use of fossil-based ones. In this context, natural fillers are extensively investigated and polymeric composites with a variety of natural fillers have been reported. Depending on their structure, the filler can act as a reinforcing agent or endow the matrix with higher degradability or hydrophilicity. Overall, with suitable filler content, materials with tunable properties, improved performances and lower cost are obtained.
After lignin, tannin has recently attracted significant interest as an inexpensive biobased renewable resource that is worth investigating. Tannins are composed mainly of tannic acid, a polyphenol. Structurally, tannic acid can be defined as decagalloyl glucose (central glucose molecule with 10 galloyl groups), but in fact it is a mixture of different glucoses with various galloyl moieties. In any case, tannins and tannic acid are characterized by the presence of numerous phenolic OH groups. They exhibit various interesting properties such as superior antioxidant activity, UV protection effects, it is non-toxic and biocompatible, while also presenting antibacterial properties. Owing to these characteristics, tannic acid has emerged as a promising renewable additive.
In the present work, tannic acid was used as a biobased filler to confer, among others, antioxidant properties to HDPE. Tannic acid/HDPE composites were prepared through melt-mixing and characterised via conventional techniques: infrared spectroscopy, differential scanning calorimetry, X-ray diffraction and thermogravimetric analysis. The antioxidant activity was evaluated by monitoring the reduction rate of the DPPH• radical in the composites presence via UV-Vis spectroscopy, and promising results were obtained. Furthermore, ageing studies will be conducted to investigate whether tannic acid contributes to a slower deterioration of the composite properties.
Acknowledgements
This project has received funding from the European Union's Horizon Europe Framework Programme under Grant Agreement No 101058449. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or HADEA. Neither the European Union nor the granting authority can be held responsible for them.
After lignin, tannin has recently attracted significant interest as an inexpensive biobased renewable resource that is worth investigating. Tannins are composed mainly of tannic acid, a polyphenol. Structurally, tannic acid can be defined as decagalloyl glucose (central glucose molecule with 10 galloyl groups), but in fact it is a mixture of different glucoses with various galloyl moieties. In any case, tannins and tannic acid are characterized by the presence of numerous phenolic OH groups. They exhibit various interesting properties such as superior antioxidant activity, UV protection effects, it is non-toxic and biocompatible, while also presenting antibacterial properties. Owing to these characteristics, tannic acid has emerged as a promising renewable additive.
In the present work, tannic acid was used as a biobased filler to confer, among others, antioxidant properties to HDPE. Tannic acid/HDPE composites were prepared through melt-mixing and characterised via conventional techniques: infrared spectroscopy, differential scanning calorimetry, X-ray diffraction and thermogravimetric analysis. The antioxidant activity was evaluated by monitoring the reduction rate of the DPPH• radical in the composites presence via UV-Vis spectroscopy, and promising results were obtained. Furthermore, ageing studies will be conducted to investigate whether tannic acid contributes to a slower deterioration of the composite properties.
Acknowledgements
This project has received funding from the European Union's Horizon Europe Framework Programme under Grant Agreement No 101058449. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or HADEA. Neither the European Union nor the granting authority can be held responsible for them.