(Bio)Degradable Polymeric Materials for Sustainable Future-Part 3: Degradation Studies of the PHA/Wood Flour-Based Composites and Preliminary Tests of Antimicrobial Activity.

Marta Musioł,Magdalena Klim,Izabela Radecka,Joanna Rydz,Brian Johnston,Wanda Sikorska,Piotr Kurcok,Michał Sobota,Sebastian Jurczyk,Magdalena Zięba,Henryk Janeczek

doi:10.3390/ma13092200

Abstract

The need for a cost reduction of the materials derived from (bio)degradable polymers forces research development into the formation of biocomposites with cheaper fillers. As additives can be made using the post-consumer wood, generated during wood products processing, re-use of recycled waste materials in the production of biocomposites can be an environmentally friendly way to minimalize and/or utilize the amount of the solid waste. Also, bioactive materials, which possess small amounts of antimicrobial additives belong to a very attractive packaging industry solution. This paper presents a study into the biodegradation, under laboratory composting conditions, of the composites that consist of poly[(R)-3-hydroxybutyrate-co-4-hydroxybutyrate)] and wood flour as a polymer matrix and natural filler, respectively. Thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy were used to evaluate the degradation progress of the obtained composites with different amounts of wood flour. The degradation products were characterized by multistage electrospray ionization mass spectrometry. Also, preliminary tests of the antimicrobial activity of selected materials with the addition of nisin were performed. The obtained results suggest that the different amount of filler has a significant influence on the degradation profile.

Highlights

The waste of products from conventional plastics is one of the most troublesome categories of refuse, which is a serious threat to the environment
Samples containing 30 wt. % of wood flour had the highest, more than 20%, mass loss and water uptake on a level above 35% after 70 days incubation in water (Figure 6)
Thedegradation under laboratory and industrial composting conditions of composites made of P(3HB-co-4HB) and wood flour as well as the antimicrobial activity of selected materials with nisin were studied

Summary

Introduction

The waste of products from conventional plastics is one of the most troublesome categories of refuse, which is a serious threat to the environment. To reduce the high price of (bio)degradable polymers and to improve their physical properties, biocomposites. Wood flour is a material with low density, high stiffness, biodegradability and it is the most widespread natural, renewable and available material at low cost. A waste from woodworking and furniture companies, contains organic compounds such as cellulose, hemicellulose, and lignin. It contains simple carbohydrates, proteins, starch, tannins, essential oils, natural rubber and mineral salts. All the possibilities of using new products, including composites with the addition of recycled wood, help to reduce the environmental impact and the consumption of the conventional polymers [7]

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Conclusion