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End-of-life options for plastics include recycling and energy recovery (incineration). Taking into account the polymeric waste, recycling is the intentional action that is aimed at reducing the amount of waste deposited in landfills by industrial use of this waste to obtain raw materials and energy. The incineration of waste leads to recovery of the energy only. Recycling methods divide on mechanical (reuse of waste as a full-valuable raw material for further processing), chemical (feedstock recycling), and organic (composting and anaerobic digestion). The type of recycling is selected in terms of the polymeric material, origin of the waste, possible toxicity of the waste, and its flammability. The (bio)degradable polymers show the suitability for every recycling methods. But recycling method should be used in such a form that it is economically justified in a given case. Organic recycling in a circular economy is considered to be the most appropriate technology for the disposal of compostable waste. It is addressed for plastics capable for industrial composting such as cellulose films, starch blends, and polyesters. The biological treatment of organic waste leads also to a decrease of landfills and thereby reducing methane emissions from them. If we add to their biodegradability the absence of toxicity, we have a biotechnological product of great industrial interest. The paper presents the overview on end-of-life options useful for the (bio)degradable polymers. The principles of the circular economy and its today development were also discussed.

The gas transport properties of the mixed matrix membranes (MMM) prepared from the synthesized, structurally different poly(hydroxyimide)s (HPI) and mesoporous MCM-41 silica particles were investigated. The both series of filled and unfilled precursors were used to obtain and examine thermally rearranged (TR) polybenzoxazoles (PBO). The effect of a number and position of hydroxyl groups in HPI chains as well as that of filler presence on TR conversion was studied using FTIR, DSC, TGA, WAXD, SEM, mechanical testing, and density measurements. With 7 wt% of MCM-41 silica, gas permeability of the filled HPI precursors and that of the respective filled PBOs increased 1.5–2.2 and 4.4–15.1 times, respectively, comparing to the neat HPIs. The permeability increase along with relatively low loss of gas selectivity for filled membranes shift them towards the upper bound demonstrating that incorporation of porous fillers into polybenzoxazoles precursors can be a new approach to improve membrane performance.

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.

The use of (bio)degradable polymers, especially in medical applications, requires a proper understanding of their properties and behavior in various environments. Structural elements made of such polymers may be exposed to changing environmental conditions, which may cause defects. That is why it is so important to determine the effect of processing conditions on polymer properties and also their subsequent behavior during degradation. This paper presents original research on a specimen&rsquo, s damage during 70 days of hydrolytic degradation. During a standard hydrolytic degradation study of polylactide and polylactide/polyhydroxyalkanoate dumbbell-shaped specimens obtained by 3D printing with two different processing build directions, exhibited unexpected shrinkage phenomena in the last degradation series, representing approximately 50% of the length of the specimens irrespective of the printing direction. Therefore, the continuation of previous ex-ante research of advanced polymer materials is presented to identify any possible defects before they arise and to minimize the potential failures of novel polymer products during their use and also during degradation. Studies on the impact of a specific processing method, i.e., processing parameters and conditions, on the properties expressed in molar mass and thermal properties changes of specimens obtained by three-dimensional printing from polyester-based filaments, and in particular on the occurrence of unexpected shrinkage phenomena after post-processing heat treatment, are presented.

This paper presents ex-ante examination of advanced polymer materials to detect defects and define and minimize the potential failure of novel polymer products before they arise. The effect of build directions on the properties of dumbbell-shaped specimens obtained by three-dimensional printing from polylactide and polylactide/polyhydroxyalkanoate commercial filaments was investigated, as well as the hydrolytic degradation of these specimens at 50 °C and 70 °C. Taking into account previous studies, we have found further dependences of the properties of 3D printed species before and during abiotic degradation from the orientation of printing. The initial assumption that only the contact time with the 3D printer platform leads to an increase in the crystalline phase during printing turned out to be insufficient. Further investigations of individual parts of the dumbbell-shaped specimens showed that the size of the specimens' surface in contact with the platform also affected the structural ordering of the material.

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.

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.

Graphenic materials have been produced from thermally treated highly metamorphosed carbon material – anthracite using two different methods: (1) the improved Hummers method followed by thermal redu...

The use of biobased plastics is of great importance for many applications. Blending thermoplastic polylactide (PLA) with polyhydroxyalkanoate (PHA) enables the formulation of a more mechanically powerful material and this enables tailored biodegradation properties. In this study we demonstrate the 3D printing of a PLA/PHA blend as a potential candidate for biocompatible material applications. The filament for 3D printing consisted of PHA, which contains predominantly 3-hydroxybutyrate units and a small amount of 3-hydroxyvalerate units, as revealed by multistage mass spectrometry (ESI-MSn). This research found that the properties of 3D printed species before and during abiotic degradation are dependent on printing orientation. Furthermore, the 3D printed specimens exhibited good biocompatibility with HEK293 cells, indicating real promise as biological scaffolds for tissue engineering applications.

Three (two novel) conjugated, thiophene phenylene based polyazomethines have been obtained parallel, by chemical vapour deposition (CVD) and by chemical synthesis. They were subsequently identified and characterised by an X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry and detailed UV–Vis-NIR spectroscopy. Absorption spectra of the polymers' solutions and thin films have been examined. The spectra of polyazomethines without, with methoxy and with octyloxy side chains attached to the polymer backbone showed a conjugation-improving effect of alkyloxy side chain introduction. A comparison of spectra of the same polyazomethine's thin films deposited separately by spin-on and CVD methods revealed decrease in conjugation of compounds obtained during CVD. Additionally, amorphous character of the investigated thin films allowed to calculate the absorption edge parameters, in a way typical for amorphous semiconductor and to discuss their values in the context of chemical structure and deposition method. Surface imaging with atomic force microscope revealed different character of thin films deposited by spin-on and CVD methods.

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.

Materials with shape memory effect (SME) have already been widely used in the medical field. The interesting part of this group is represented by double function materials. The bioresorption and SME ability are common in polyesters implants. The first information about vascular stent made of bioresorbable polyester with SME was published in 2000. However, there are not many investigations about SME control of elements in the aspect of material processing. In the present work, the ability to control the shape memory (SM) of bioresorbable and semicrystalline poly(L-lactide) (PLLA) is investigated. The studies are based on the unexpected effect of material orientation which was demonstrated even at low percentage deformation in crystallized mould injected material. The presented studies revealed that the different degrees of crystallinity obtained during processing might be a useful switch to create a tailored SME for a specific application. The prepared samples of variable morphology revealed a possibility to control the value of material stress during permanent shape recovery. The degree of shape recovery of the prepared samples was also controlable. The highest stress value observed during permanent shape recovery reached 10MPa for the sample annealed 60min at 115°C even when the sample was only deformed in 8%. The other significant aspect of this work is to present the problem of slow crystallization of the material during and after processing (cooling rate) as well as the possibility of negative SME change during the shelf life of the fabric.

This study investigated the molecular structure of the polyhydroxyalkanoate (PHA) produced via a microbiological shake flask experiment utilizing oxidized polypropylene (PP) waste as an additional carbon source. The bacterial strain Cupriavidus necator H16 was selected as it is non-pathogenic, genetically stable, robust, and one of the best known producers of PHA. Making use of PHA oligomers, formed by controlled moderate-temperature degradation induced by carboxylate moieties, by examination of both the parent and fragmentation ions, the ESI-MS/MS analysis revealed the 3-hydroxybutyrate and randomly distributed 3-hydroxyvalerate as well as 3-hydroxyhexanoate repeat units. Thus, the bioconversion of PP solid waste to a value-added product such as PHA tert-polymer was demonstrated.

This study describes the preparation, physicochemical characterization and the biological studies of the polymeric delivery systems of proanthocyanidins (PCAN) extracted from Pelargonium sidoides for the potential use as wound dressings. In this study 20 wt% PCAN demonstrated good antimicrobial activity against Staphylococcus aures, a gram-positive wound pathogen. Poly(D,L-lactide) and atactic poly[(R,S)-3-hydroxybutyrate] biopolymers were used to construct biodegradable dressings. A series of polylactide/poly[(R,S)-3-hydroxybutyrate] (P(D,L)LA/a-PHB) blends, containing 10, 20, and 30 wt% of a-PHB were prepared and characterized by means of NMR, GPC, FT-IR, and DSC. Based on the findings, the P(D,L)LA/a-PHB [70/30 wt%] blend with the best thermomechanical properties (Tg value equal 37 °C) was chosen for the preparation of two kinds of electrospun mats, both with and without PCAN. About 50% of PCAN was released from the tested mats during the first 10–12 days of incubation. The electrospun mats with elastic properties, ensuring compatibility with the wound topology, were obtained. The studies of hydrolytic degradation of the constructed mats allowed us to gain complete knowledge of their hydrolysis process, and examine the PCAN release profile as well as identify and characterize the molecular structure of the degradation products of the developed delivery system. Furthermore, preliminary cytotoxicity MTT tests (in vitro) results support the potential application of PCAN-loaded (P(D,L)LA/a-PHB) electrospun mats in wound dressings.

In this study we present a novel and simple approach to improve the gas separation performance of the thermally rearranged membranes, which involves doping the polyimide precursors (HPI) with ionic liquid (IL), and carrying out its degradation along with the conversion process to polybenzoxazole (PBO) in order to facilitate the formation of larger and /or more numerous free volumes. A series of aromatic (co)poly(hydroxyimide)s based on 6FDA and HAB/4MPD diamines in different molar ratios, as well as BPADA-HAB poly(hydroxyimide) were synthesized as the precursors to be doped with IL and thermally rearranged to PBO. The structural modifications of the precursor backbone were applied to study the impact of IL on the physical properties, thermal conversion process, as well as gas transport properties of the doped polymers with different chain rigidities. The pure and IL doped (co)polyimides and their thermally rearranged counterparts were characterized by WAXD, DSC, TGA, tensile tests, and PALS, and examined in pure gas permeation experiments. TR conversion temperature was considerably reduced by IL doping (e.g. by 126 °C). This effect depended on the precursor chemical structure and the IL content. After thermal rearrangement of the IL doped HPIs, the membrane permeability to gases increased significantly compared to the un-doped analogues (e.g. 2 fold increase for O2 permeability). The permeability increase was larger for the higher IL content and the precursor chain rigidity. This was accompanied by a relatively small loss in selectivity leading to the performance shift towards the 2008 upper bound. The differences in permeability among the samples correlated with the free volume size from PALS. In particular, a very good correlation was obtained (r2 = 0.958), when the data fitted to the Cohen-Turnbull model concerned only PBO samples with low cohesive energy density. Further studies on HPIs doped with IL with lower degradation temperatures are suggested to mitigate polymer degradation and explore this new method for the design of improved gas separation membrane materials.

The rigid foils obtained from polylactide (PLA) with synthetic poly[(R,S)-3-hydroxybutyrate] ((R,S)-PHB) can be used for production of food packages, which is important enhancement of biodegradable materials application. The biodegradable rigid packaging can be subjected to organic recycling together with food remains. The degradation of PLA and its blend with (R,S)-PHB as rigid foils were studied under industrial composting conditions. Incubation of these materials in water at 70 °C (hydrolytic degradation) was conducted as reference experiment. Gel permeation chromatography, electrospray mass spectrometry, nuclear magnetic resonance and differential scanning calorimetry were used to determine the progress of degradation during incubation in selected environments. The present results showed that PLA-based rigid foil degrades under industrial composting conditions. In the blends, (R,S)-PHB content was found to accelerate the degradation process under industrial composting conditions in comparison with the reference experiment. Thus, it is possible to control the degradation process by changing the composition of polymer blend.

Welding technology may be considered as a promising processing method for the formation of packaging products from biopolymers. However, the welding processes used can change the properties of the polymer materials, especially in the region of the weld. In this contribution, the impact of the welding process on the structure and properties of biopolymer welds and their ability to undergo hydrolytic degradation will be discussed. Samples for the study were made from polylactide (PLA) and poly(3-hydroxyalkanoate) (PHA) biopolymers which were welded using two methods: ultrasonic and heated tool welding. Differential scanning calorimetry (DSC) analysis showed slight changes in the thermal properties of the samples resulting from the processing and welding method used. The results of hydrolytic degradation indicated that welds of selected biopolymers started to degrade faster than unwelded parts of the samples. The structure of degradation products at the molecular level was confirmed using mass spectrometry. It was found that hydrolysis of the PLA and PHA welds occurs via the random ester bond cleavage and leads to the formation of PLA and PHA oligomers terminated by hydroxyl and carboxyl end groups, similarly to as previously observed for unwelded PLA and PHA-based materials.

Excessive levels of plastic waste in our oceans and landfills indicate that there is an abundance of potential carbon sources with huge economic value being neglected. These waste plastics, through biological fermentation, could offer alternatives to traditional petrol-based plastics. Polyhydroxyalkanoates (PHAs) are a group of plastics produced by some strains of bacteria that could be part of a new generation of polyester materials that are biodegradable, biocompatible, and, most importantly, non-toxic if discarded. This study introduces the use of prodegraded high impact and general polystyrene (PS0). Polystyrene is commonly used in disposable cutlery, CD cases, trays, and packaging. Despite these applications, some forms of polystyrene PS remain financially and environmentally expensive to send to landfills. The prodegraded PS0 waste plastics used were broken down at varied high temperatures while exposed to ozone. These variables produced PS flakes (PS1&ndash, 3) and a powder (PS4) with individual acid numbers. Consequently, after fermentation, different PHAs and amounts of biomass were produced. The bacterial strain, Cupriavidus necator H16, was selected for this study due to its well-documented genetic profile, stability, robustness, and ability to produce PHAs at relatively low temperatures. The accumulation of PHAs varied from 39% for prodegraded PS0 in nitrogen rich media to 48% (w/w) of dry biomass with the treated PS. The polymers extracted from biomass were analyzed using nuclear magnetic resonance (NMR) and electrospray ionization tandem mass spectrometry (ESI-MS/MS) to assess their molecular structure and properties. In conclusion, the PS0&ndash, 3 specimens were shown to be the most promising carbon sources for PHA biosynthesis, with 3-hydroxybutyrate and up to 12 mol % of 3-hydroxyvalerate and 3-hydroxyhexanoate co-monomeric units generated.

Using conventional nondegradable and noncompostable polymers has a significant negative impact on the environment, so biodegradable polymers can attract much attention in regards to the current interest in the field of sustainable development, recycling, or environmental protection. Morphological and structural transformations resulting from the degradation of the material have a significant impact on the polymer material properties. Thus, evaluation and understanding of the structure, properties, and behavior of advanced materials for perspective food packaging applications is important to avoid degradation during storage. This review focuses on biodegradable polymer materials with approved or potential applications in food packaging. The major groups of biodegradable natural, microbial, and synthetic polymers will briefly be discussed with regard to properties required for packaging materials, like permeability, physical and mechanical properties, antioxidative and antimicrobial additives, plasticization, and biodegradability, based on studies reported in the literature as well as future trends.

The semicrystalline poly(L-lactide) (PLLA) belongs to the materials with shape memory effect (SME) and as a bioresorbable and biocompatible polymer it have found many applications in medical and pharmaceutical field. Assessment of the SME impact on the polymer degradation profile plays crucial role in applications such as drug release systems or in regenerative medicine. Herein, the results of in vitro degradation studies of PLLA samples after SME full test cycle are presented. The samples were loaded and deformed in two manners: progressive and non-progressive. The performed experiments illustrate also influence of the material mechanical damages, caused e.g. during incorrect implantation of PLLA product, on hydrolytic degradation profile. Apparently, degradation profiles are significantly different for the material which was not subjected to the deformation and the deformed ones. The materials after deformation of 50% (in SME cycle) was characterized by non-reversible morphology changes. The effect was observed in deformed samples during the SME test which were carried out ten times.

The main aim of the present study was to determine the behavior of the specimens from Ecovio, in the form of dumbbell-shaped samples and films, during degradation in selected cosmetic ingredients such as water and paraffin. The (bio)degradation test of the prototype cosmetic package (sachet) made from a PBAT (poly[(1,4-butylene adipate)–co–(1,4-butylene terephthalate)]) and PLA (polylactide) blend was investigated under industrial composting conditions, and compared with the sample behavior during incubation in cosmetic media at 70 °C. During the degradation tests, the changes of the samples were evaluated using optical microscopy, 1H NMR (proton nuclear magnetic resonance) and GPC (gel permeation chromatography) techniques. The structures of the degradation products were investigated using ESI-MSn (mass spectrometry with electrospray ionization on positive and negative ions) analysis. The thermal properties of selected materials were determined by DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis) analysis. It was concluded that the PBAT and PLA blend studied had a good stability during aging in cosmetic media, and could be recommended for long-shelf-life compostable packaging of cosmetics, especially with oily ingredients.

Knowledge of degradation and impairment phenomena of (bio)degradable polymeric materials under operating conditions, and thus the selection of test procedures and prediction of their behavior designates the scope and capabilities as well as possible limitations of both: the preparation of the final product and its durability. The main novelty and objective of this research was to determine the degradation pathways during testing of polylactide and polylactide/polyhydroxyalkanoate materials made with three-dimensional printing and the development of a new strategy for the comprehensive characterization of such complex systems including behavior during waste disposal. Prototype objects were subjected to tests for damage evolution performed under simulating operating conditions. The reference samples and the tested items were characterized by gel permeation chromatography and differential scanning calorimetry to determine changes in material properties. The studies showed that: polyhydroxyalkanoate component during accelerated aging and degradation in environments rich in microorganisms accelerated the degradation of the material, paraffin accelerates polylactide degradation and slows degradation of polyhydroxyalkanoate-based material, under the influence of an environment rich in enzymes, paraffin contamination accelerates biodegradation, under the influence of natural conditions, paraffin contamination slowed degradation, the processing conditions, in particular the printing orientation of individual parts of the container, influenced the material properties in its various regions, affecting the rate of degradation of individual parts.

The degree of degradation of pure poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] and its composites with cork incubated under industrial and laboratory composting conditions was investigated. The materials were parallelly incubated in distilled water at 70 &deg, C as a reference experiment (abiotic condition). It was demonstrated that addition of the cork into polyester strongly affects the matrix crystallinity. It influences the composite degradation independently on the degradation environment. Moreover, the addition of the cork increases the thermal stability of the obtained composites, this was related to a smaller reduction in molar mass during processing. This phenomenon also had an influence on the composite degradation process. The obtained results suggest that the addition of cork as a natural filler in various mass ratios to the composites enables products with different life expectancies to be obtained.

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.