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

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.

Antibacterial and Antiviral Functional Materials: Chemistry and Biological Activity toward Tackling COVID-19-like Pandemics

“… 316 , 317 Furthermore, the antimicrobial ability is also significantly affected by other physio-chemical features of NPs such as morphology, oxidation states, and the aggregation/dissolution state. 222 , 318 , 319 Hence, Ag NPs of different shapes such as beads, mats, rods, nanoprisms, and sheets are being reported for their specific antibacterial effects. Ag NPs based antimicrobial wound therapy has proven to be an effective tool to cure wounds and is now widely used in wound healing products.…”

An Overview of the Antimicrobial Properties of Lignocellulosic Materials

“…The use of wood flour in polymer composites with antimicrobial activity is reported in the literature for different polymer matrices, such as polyvinyl chloride (PVC) [ 93 ], polyhydroxyalkanoate (PHA) [ 94 , 95 ], polylactic acid (PLA) [ 96 ], poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHVB) [ 97 ] and polyvinyl alcohol (PVA) [ 98 ]. The composites with PHA and PLA presented good antibacterial activity against E. coli .…”

End-of-Life Options for (Bio)degradable Polymers in the Circular Economy

“…The compostable products should also be made with biodegradable additives. In the literature, the numerous publications on the degradation behaviour of polymers in different environments such maturing compost (after the active composting stage), industrial compost, compost with the addition of activated sludge, and in home-type composters can be found [106][107][108][109][110][111][112][113][114][115][116][117][118]. For example, the studies of the whole and complete package of PLA Biota bottles conducted under real composting condition in a special preparing piles show that (bio)degradation degree of the tested PLA bottles is about 85% after 58 days of process [106], while for the Novamont plastic, Mater-Bi degraded only in 7.1% within a period of 72 days of composting [114].…”

“…It was concluded that both hydrolytic degradation and enzymatic degradation occur in the compost. Moreover, the production of such (bio)degradable materials could be a way for utilisation of waste from the wood industry fit with the idea of a circular economy [112]. Recently, the degradation tests of PLA prototype packaging in industrial compost (in a composting pile and in a BIODEGMA system) and, for comparison, under laboratory, controlled conditions, using respirometric method, were conducted.…”