• (Bio)degradable polymeric materials for a sustainable future – part 1. Organic recycling of PLA/PBAT blends in the form of prototype packages with long shelf-life

      Musioł, Marta; Sikorska, Wanda; Janeczek, Henryk; Wałach, Wojciech; Hercog, Anna; Johnston, Brian; Rydz, Joanna (Elsevier, 2018-04-23)
      Prediction studies of advanced (bio)degradable polymeric materials are crucial when their potential applications as compostable products with long shelf-life is considered for today’s market. The aim of this study was to determine the effect of the polylactide (PLA) content in the blends of PLA and poly(butylene adipate-co-terephthalate) (PBAT); specifically how the material’s thickness corresponded to changes that occurred in products during the degradation process. Additionally, the influence of talc on the degradation profile of all samples in all environments was investigated. It was found that, differences in the degradation rate of materials tested with a similar content of the PLA component could be caused by differences in their thickness, the presence of commercial additives used during processing or a combination of both. The obtained results indicated that the presence of talc may interfere with materials behavior towards water and consequently alter their degradation profile.
    • Forensic engineering of advanced polymeric materials Part IV: Case study of oxo-biodegradable polyethylene commercial bag – Aging in biotic and abiotic environment

      Musioł , Marta; Rydz, Joanna; Janeczek, Henryk; Radecka, Iza; Jiang, Guozhan; Kowalczuk , Marek (Elsevier, 2017-04-03)
      The public awareness of the quality of environment stimulates the endeavor to safe polymeric materials and their degradation products. The aim of the forensic engineering case study presented in this paper is to evaluate the aging process of commercial oxo-degradable polyethylene bag under real industrial composting conditions and in distilled water at 70 °C, for comparison. Partial degradation of the investigated material was monitored by changes in molecular weight, thermal properties and Keto Carbonyl Bond Index and Vinyl Bond Index, which were calculated from the FTIR spectra. The results indicate that such an oxo-degradable product offered in markets degrades slowly under industrial composting conditions. Even fragmentation is slow, and it is dubious that biological mineralization of this material would occur within a year under industrial composting conditions. The slow degradation and fragmentation is most likely due to partially crosslinking after long time of degradation, which results in the limitation of low molecular weight residues for assimilation. The work suggests that these materials should not be labeled as biodegradable, and should be further analyzed in order to avoid the spread of persistent artificial materials in nature.
    • Forensic engineering of advanced polymeric materials. Part III - Biodegradation of thermoformed rigid PLA packaging under industrial composting conditions.

      Musioł , Marta; Sikorska, Wanda; Adamus, Grazyna; Janeczek, Henryk; Richert, Jozef; Malinowski, Rafal; Jiang, Guozhan; Kowalczuk , Marek (Elsevier, 2016-04-18)
      This paper presents a forensic engineering study on the biodegradation behaviour of prototype packaging thermoformed from PLA-extruded film and plain PLA film under industrial composting conditions. Hydrolytic degradation in water was conducted for reference. The effects of composting duration on changes in molar mass, glass transition temperature and degree of crystallinity of the polymeric material were monitored using gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The chemical structure of water soluble degradation products of the polymeric material was determined using nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS). The results show that the biodegradation process is less dependent on the thermoforming process of PLA and more dependent on the composting/degradation conditions that are applied. The increase in the dispersity index, leading to the bimodal molar mass distribution profile, suggests an autocatalytic hydrolysis effect at the early stage of the composting process, during which the bulk hydrolysis mechanism dominantly operates. Both the prototype PLA-packaging and PLA rigid film samples were shown to have a gradual increase in opacity due to an increase in the degree of crystallinity.
    • Prediction studies of environment-friendly biodegradable polymeric packaging based on PLA. Influence of specimens’ thickness on the hydrolytic degradation profile

      Sikorska, W.; Musioł, M.; Rydz, J.; Zięba, M.; Rychter, P.; Lewicka, K.; Šiškova, A.; Mosnáčková, K.; Kowalczuk, Marek; Adamus, G. (Elsevier, 2018-07-11)
      Application of new biodegradable polymer packaging based on polylactide (PLA), susceptible to organic recycling, can help in the waste reduction in landfills. In this paper, the results of the study on abiotic degradation of PLA and its blend containing 15 mol% of poly[(R,S)-3-hydroxybutyrate], as a model for the first step of organic recycling were presented. The samples used for this study have different shapes and thicknesses: rigid films and cuboid-bars. Particular emphasis was placed on determining the pattern of degradation products released into the medium. Originally, the results of present study revealed that the application of electrospray ionization mass spectrometry supported by high performance liquid chromatography allowed envisaging the differences in the degradation products pattern released from the studied PLA-based samples differing in thickness. The significant differences in degradation products pattern were predominately observed in the first steps of incubation process and are caused by an autocatalytic effect, which occurs mainly during degradation of the large size PLA samples. Although, the thickness of PLA-based packaging changes the degradation product patterns, however this does not increase the total amounts of acids released to the medium. Thus, it may be concluded that thickness should not affect significantly organic recycling of the packaging.
    • Rethinking and optimising post-consumer packaging waste: A sentiment analysis of consumers’ perceptions towards the introduction of a deposit refund scheme in Scotland

      Oke, A; Osobajo, O; Obi, L; Omotayo, T; Aberdeen Business School, Robert Gordon University, Garthdee Road, Aberdeen AB10 7QE, UK. Electronic address: a.oke1@rgu.ac.uk. (Elsevier, 2020-09-23)
      © 2020 Elsevier Ltd Packaging waste production, especially single-use containers, is exerting detrimental effects on terrestrial and aquatic ecosystems, including human health. To internalise the externalities associated with single-use containers, different instruments, including a deposit refund scheme (DRS), have been operationalised in many countries. Therefore, DRS is introduced in Scotland to reduce plastic litters by increasing recycling rates and incentivising pro-environmental behavioural change. This study addresses the complexity of single-use plastic containers by analysing consumers’ perceptions regarding the introduction of DRS in Scotland. Using 940 comments from the BBC “Have Your Say” messageboard, this study adopts sentiment analysis to understand consumers’ opinions about the introduction and implementation of DRS in Scotland. Findings suggest that a UK-wide scheme that is similar in terms of operations and structure is required for DRS to be successful. While consumers’ knowledge and opinions about DRS are mixed, the efficacy of DRS including its relevance is questioned and raises doubts about its contribution to sustainability. The findings imply the need for UK countries to negotiate and collaborate on appropriate and attractive interventions in addressing post-consumer single-use plastic containers. The implications of the findings for policy and practice, especially in improving the operations of DRS are further discussed.