The Role of Birch Tar in Changing the Physicochemical and Biocidal Properties of Polylactide-Based Films

• Published in: International journal of molecular sciences Vol. 23; no. 1; p. 268
• Main Authors: Richert, Agnieszka, Olewnik-Kruszkowska, Ewa, Dąbrowska, Grażyna B, Dąbrowski, Henryk P
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27-12-2021; MDPI
• Subjects: agriculturalfilms; Agriculture; Anti-Bacterial Agents - pharmacology; Antibacterial activity; antibacterial properties; Antiinfectives and antibacterials; Atomic force microscopy; Bacteria; Bacteria - drug effects; Betula - chemistry; Biocides; birch tar; Calcium Chloride - chemistry; Chemical Phenomena; Disinfectants - pharmacology; Elongation; Microbial Sensitivity Tests; Microorganisms; Morphology; Permeability; Plastics - chemistry; Polyesters - pharmacology; Polyethylene glycol; Polylactic acid; polylactide; Polymers; Recesses; Scanning electron microscopy; Spectroscopy, Fourier Transform Infrared; Spectrum analysis; Steam; Surface Properties; Tar; Tars - chemistry; Topography; Veterinary medicine; Water vapor; birch tar; antibacterial properties; polylactide; agriculturalfilms
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23010268

The objective of this study was to produce bactericidal polymer films containing birch tar (BT). The produced polymer films contain PLA, plasticiser PEG (5% wt.) and birch tar (1, 5 and 10% wt.). Compared to plasticised PLA, films with BT were characterised by reduced elongation at break and reduced water vapour permeability, which was the lowest in the case of film with 10% wt. BT content. Changes in the morphology of the produced materials were observed by performing scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis; the addition of BT caused the surface of the film to be non-uniform and to contain recesses. FTIR analysis of plasticised PLA/BT films showed that the addition of birch tar did not change the crystallinity of the obtained materials. According to ISO 22196: 2011, the PLA film with 10% wt. BT content showed the highest antibacterial effect against the plant pathogens
,
,
,
,
. It was found that the introduction of birch tar to plasticised PLA leads to a material with biocidal effect and favourable physicochemical and structural properties, which classifies this material for agricultural and horticultural applications.