Food Packaging and Shelf Life 26 (2020) 100593 Available online 2 November 2020 2214-2894/© 2020 Elsevier Ltd. All rights reserved. Plant extracts as natural additives for environmentally friendly polylactide flms Krzysztof Moraczewski a, *, Alona Pawłowska a , Magdalena Stepczy´ nska a , Rafał Malinowski b , Daniel Kaczor b , Bogusław Budner c , Krzysztof Gocman d , Piotr Rytlewski a a Kazimierz Wielki University, Chodkiewicza 30, 85-064, Bydgoszcz, Poland b Łukasiewicz Research Network - Institute for Engineering of Polymer Materials and Dyes, Marii Skłodowskiej-Curie 55, 87-100, Toru´ n, Poland c Institute of Optoelektronics, Military University of Technology, gen. Sylwestra Kaliskiego 2, 00-908, Warsaw, Poland d Faculty of Mechanical Engineering, Military University of Technology, gen. Sylwestra Kaliskiego 2, 00-908, Warsaw, Poland A R T I C L E INFO Keywords: Polylactide Natural polifeonols Plant extracts Polymer flms ABSTRACT The use of biodegradable polymers derived from renewable sources may in the future be a solution to the problem of environmental pollution with polymer waste. By using natural fllers and additives in addition to the biodegradable matrix, we are able to obtain truly eco-fendly green materials. The paper presents the result of selected properties of polylactide flms containing natural coffee, cocoa or cinnamon extracts which primarily were proposed as natural antioxidants. The focus was on properties relevant to the packaging industry such as color and transparency, surface roughness, wettability, surface energy, friction coeffcient, adhesion strength and gas permeability. It was found that the extracts used at the appropriate contents have a benefcial effect on the studied properties. The obtained results were often better not only than the values obtained for pure polymer, but also better than the values obtained for the flm containing a synthetic anti-aging compound. It can therefore be concluded that the proposed plant extracts have a positive effect not only on the aging resistance of polylactide, but also other properties of this polymer. They can be therefore an alternative to synthetic additives. 1. Introduction It is diffcult to imagine the modern world without polymer mate- rials. Just look around to notice how important they are in everyday life (Leal Filho et al., 2019; Rodrigues et al., 2019; Stachowitsch, 2019). However, only 70 years of production of polymer materials was enough to get the problem of plastic waste out of control. The problem of polymer waste ending up in the as environment burden is huge (Leb- reton & Andrady, 2019). Only 30 % of the total polymer materials that have been manufactured are still used. 60 % - about 4.9 billion tons - is unprocessed in any way. Since the late 1980s, the so-called The Great Pacifc Garbage Patch, consisting of 80 % polymer materials is being formed (Critchell et al., 2019; Geyer, Jambeck, & Law, 2017). Conser- vative estimates estimate its area to be around 700,000 square meters (roughly the size of Russia). Conservative estimates estimate its area to be around 700,000 square meters (roughly the size of Russia). This problem does not belong to only one hemisphere. A similar phenomenon also occurs in the south of the Atlantic Ocean (Ryan, Dilley, Ronconi, & Connan, 2019). There are three ways to reduce the amount of polymer wastes in the environment. The frst is to reduce the production of polymer materials. However, this is diffcult to imagine. On the contrary, their production increases every year. It should not be expected that this trend will stop in the coming years. The second way is to increase the process of recycling plastic waste. Fortunately, this trend is becoming more and more important and visible all over the world, not only in highly developed countries. The third solution is to increase the use of biodegradable polymers, especially those that are obtained from renewable raw ma- terials. An effective combination of the last two methods can visibly halt the growth of residual waste and have a positive impact on the environment. The main advantage of biodegradable polymers is that they degrade completely under appropriate conditions within a few months (Siracusa, Rocculi, Romani, & Rosa, 2008). Biodegradation is a process in which polymeric materials are degraded under the infuence of microorgan- isms - primarily yeast, bacteria and fungi. The time at which decom- position occurs is determined by environmental conditions - the appropriate humidity and ambient temperature - and the properties of * Corresponding author. E-mail address: kmm@ukw.edu.pl (K. Moraczewski). Contents lists available at ScienceDirect Food Packaging and Shelf Life journal homepage: www.elsevier.com/locate/fpsl https://doi.org/10.1016/j.fpsl.2020.100593 Received 22 January 2020; Received in revised form 23 June 2020; Accepted 19 October 2020