Succinate Adipate Research Articles

The effect of biodegradable polymer blending on the disintegration rate of PHBV, PBS and PLA in soil

This study generates new insights into the disintegration phenomena that take place upon blending different classes of biodegradable polymers. Polymer blending is found to be an effective method to tailor the disintegration rate of these polymers in soil. It is shown that the biodegradation of poly(hydroxybutyrate-valerate) (PHBV) can be accelerated by blending with polybutylene succinate adipate (PBSA) and polycaprolactone (PCL). The observed high rate of disintegration of polybutylene succinate (PBS) in soil (severe deterioration in 4 weeks, and fragmentation in 4 months) does not fully align with its current reputation in the market as a polymer that is non-biodegradable in soil. Disintegration trials executed in soil media with different inoculants demonstrate that the biodegradation rate of PBS in soil is highly dependent on the specific soil conditions. Moreover, it is shown that the biodegradation of PBS can be substantially accelerated by blending it with PBSA (fragmentation in 8 weeks). Finally, it is shown that the disintegration of polylactic acid (PLA) in soil can be enhanced by blending it with PCL. Experiments that monitor the CO2 evolution of these blends, both in soil and in home composting environments, demonstrate that not just the disintegration, but also the overall biodegradation of PLA is enhanced by blending with PCL (39% conversion to CO2 in 12 months incubation in soil; 89% conversion to CO2 in 6 months incubation in home composting conditions). This opens up possibilities for targeted blending strategies to reduce potential accumulation of PLA-based plastics in soil environments.

Poly(lactic acid) (PLA)/poly(butylene succinate adipate) (PBSA) films with Micro fibrillated cellulose (MFC) and cardanol for packaging applications

Micro Fibrillated Cellulose (MFC) has emerged as a promising component in film formulations due to its unique barrier prope.rties. In this study, to best of our knowledge, cardanol, a biobased plasticizer derived from cashew processing, was employed for the first time, as a dispersing aid for MFC, during a liquid assisted extrusion technique with a Poly(lactic acid) (PLA)/Poly(butylene succinate adipate) (PBSA) blend. The aim of the work is the production of PLA/PBSA/MFC films for packaging applications. The addition of different MFC amount was investigated (added at 0.5, 0.75 and 1 wt.% concentrations). The results obtained are very interesting, in fact from one hand Cardanol improved the compatibility between PLA and PBSA and avoided the MFC agglomeration. On the other hand, micro fibrillated cellulose ensured a stable film blowing and the achievement of enhanced barrier properties, seal ability and mechanical resistance. In particular, the best result was obtained with an MFC content of 0.75 wt.% for which a good compromise in terms of films ductility, barrier properties and seal ability was achieved.

Development and Optimization of the Extrusion of Potato Peel–Based Biocomposite Films

ABSTRACTSide streams from the agricultural and food industries are considered an interesting alternative source for the production of packaging materials due to their composition. However, their use often involves complex and energy‐intensive extraction of individual components. Therefore, this study investigated the application of entire potato peels, without prior extraction, to produce extruded films. Potato peels (PP) and biobased polybutylene succinate adipate (BioPBS) at 1:0, 3:2, 1:1 and 2:3 ratios were used to produce pellets and films in a two‐stage extrusion process. The influence of PP concentration, the addition of maleic anhydride and tartaric acid as compatibilizers and the addition of carnauba wax on the film properties were characterized in terms of morphological, mechanical, physicochemical and thermal properties. Films with a high PP content (50%–100%) showed weak mechanical properties. However, increasing the BioPBS content to PP/PBS 2:3 resulted in a significant increase in tensile strength and elongation at break to 6.20 MPa and 38.09%, respectively, and significantly reduced the water vapour permeability of the film to 5.5 × 10−6 gm/m2 d Pa. The use of 1% maleic anhydride had no significant effect on tensile strength (6.23 MPa), but further increased the elasticity to 65.48%, with no additional effect on barrier properties. The addition of 0.5% tartaric acid showed a similar elongation at break (56.23%) while significantly increasing the tensile strength to 6.56 MPa. The incorporation of 5% carnauba wax increased the surface hydrophobicity of the films from 69.5° to 99.7°, but at the expense of a decrease in mechanical properties.

Development of PBS/Nano Composite PHB-Based Multilayer Blown Films with Enhanced Properties for Food Packaging Applications.

Biobased and biodegradable plastics have emerged as promising alternatives to conventional plastics offering the potential to reduce environmental impacts while promoting sustainability. This study focuses on the production of multilayer blown films with enhanced functional properties suitable for food packaging applications. Films were developed through co-extrusion in a three-layer film configuration, with Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) as the external and internal layers, respectively. The functional layer consisted of Polyhydroxybutyrate (PHB) enhanced with nanoclays Cloisite® 30B at varying weight ratios. Films were also processed by manipulating the extruder screw speed of the functional layer to investigate its impact on the functional properties. Rheology, mechanical strength, and barrier performance were characterised to establish correlations between processing conditions and functional layer blends (Cloisite® 30B/PHB) on the properties of the resultant films. Rheological test results indicated that the system with 5% Cloisite® had the best polymer/nanofiller matrix dispersion. Mechanical and permeability tests showed that by varying the process conditions (the alteration of the thickness of the functionalized layer) resulted in an improvement in mechanical and barrier properties. Furthermore, the addition of the nanofiller resulted in a stiffening of the film with a subsequent decrease in permeability to oxygen and water vapour.

In-Line Chemical Composition Monitoring for the Injection Molding Process of Biodegradable Polymer Blends Using Simultaneous Measurement of Near-Infrared Diffuse Reflectance and Transmission Spectra.

In the processing of polymer blends and composites, in-line near-infrared (NIR) spectroscopy enables monitoring of the composition and its composite uniformity and contributes to rapid process development and quality control. However, in the injection molding process, the study of the composition of polymer materials has been delayed due to high-pressure conditions. Our research group developed NIR probes for transmission and diffuse reflectance measurements that can withstand high-pressure and temperature conditions up to 130 MPa and 200 °C. In this research, transmission and diffuse reflectance spectra were measured inline during the injection molding process of polymer blends of poly(lactic acid) and polybutylene succinate adipate. The intensity of each polymer band in the second-derivative spectra exhibited a monotonic increase or decrease in response to changes in the blend ratio. Using transmission and diffuse reflectance spectra as explanatory variables of the partial least squares regression model simultaneously, the model showed high estimation accuracy for the entire region of the blend ratio. Finally, this model was applied to monitor the polymer changeover operation, and the change in the blend ratio in the molded product was successfully estimated in line.

A lesson from polybutylene succinate plastisphere to the discovery of novel plastic degrading enzyme genes in marine vibrios.

Polybutylene succinate (PBS) is an eco-friendly green plastic. However, PBS was shown as being non-biodegradable in marine environments, and up until now, only a limited number of PBS-degrading marine microbes have been discovered. We first set up in vitro PBS- and PBSA (polybutylene succinate adipate)-plastispheres to characterize novel PBS-degrading marine microbes. Microbial growth and oxygen consumption were observed in both PBS- and PBSA-plastispheres enriched with natural seawater collected from Usujiri, Hokkaido, Japan, and Vibrionaceae and Pseudoalteromonadaceae were significantly enriched on these films. Further gene identification indicated that vibrios belonging to the Gazogenes clade possess genes related to a PBS degrading enzyme (PBSase). The PBS degradation assay for six Gazogenes clade vibrios identified Vibrio ruber, Vibrio rhizosphaerae, and Vibrio spartinae as being capable of degrading PBS. We further identified the gene responsible for PBSase from the type strain of V. ruber, and the purified recombinant vibrio PBSase was found to have low-temperature adaptation and was active under high NaCl concentrations. We also provided docking models between the vibrio PBSase and PBS and PBSA units to show how vibrio PBSase interacts with each substrate compared to the Acidovorax PBSase. These results could contribute to a more sustainable society through further utilization of PBS in marine environments and plastic recycling.

Manufacture, physical properties, and degradation of biodegradable polyester microbeads

The conventional microbeads in cosmetics and personal care products comprise non-biodegradable plastics, which pollute the marine environment. In the present study, we used a simple melt-homogenizing method to manufacture microbeads from four biodegradable polyesters, i.e., poly(butylene succinate) (PBS), poly(butylene succinate adipate) (PBSA), poly(lactic acid) (PLA), and poly[(R)-3-hydroxybutyrate] (P(3HB)). We then determined the morphology, compression properties, and biodegradability of each polyester. The microbeads ranged in size from 25 to 200 μm, were almost spherical, and had smooth surfaces, as verified by scanning electron microscopy (SEM). The single microbeads were subjected to compression tests because their mechanical properties are correlated to their sensory performance. The compression strengths of the four plastic microbeads, which were comparable to those of commonly used microbeads such as polyethylene and polypropylene, were widely distributed. In particular, the PBSA and P(3HB) microbeads were readily biodegradable, as evaluated by enzymatic degradation and sea water degradation tests, indicating their potential as alternatives to conventional microbeads.

Overview of the mechanical, thermal and barrier properties of biobased and/or biodegradable thermoplastic materials

This study gives an overview of the most relevant processing and performance properties of a wide selection of biobased and biodegradable plastic materials that are currently commercially available. It provides the most extensive and up-to-date scientific overview of critical properties of biobased and biodegradable plastics. Materials that are tested include fully biobased polymers (polylactic acid, polyethylene, polyamide 10,10 and a range of polyhydroxy alkanoates), partially biobased polymers (polybutylene succinate, polybutylene succinate adipate, cellulose acetate, cellulose acetate propionate, polyethylene terephthalate, polytrimethylene terephthalate, an isosorbide based polycarbonate, a thermoplastic urethane and a starch based blend) and a number of fossil-based materials (polycaprolactone, polybutylene adipate terephthalate, polyglycolic acid and polypropylene). The mechanical (tensile, flexural, impact resistance and hardness), thermal (glass transition temperature, melting temperature, melt-flow index and haul-off force) and barrier (oxygen transmission rate, water vapour transmission rate) properties of all these materials were measured and are presented in a comprehensive overview. This overview shows that the majority of functionalities that are currently being offered by fossil based polymers can be met by biobased alternatives and by biodegradable materials if this is considered to be favourable at end-of-life.

Lamination of Cast Hemp Paper with Bio-Based Plastics for Sustainable Packaging: Structure-Thermomechanical Properties Relationship and Biodegradation Studies

Composite laminate recycling and waste disposal routes remain a burden to existing systems, requiring special treatment and separation. The inclusion of a plastic layer is important for several key properties that are required for food safety, which in turn has made these products exceptionally hard to substitute in food packaging. Yet, the continued use of non-degradable commodity plastics is unsustainable. In this research, we compare the four most promising biodegradable and bio-based plastics that could replace non-degradable plastics in laminates. Polyhydroxyalkanoate (PHA), polylactic acid (PLA), polybutylene succinate (PBS), and polybutylene succinate adipate (PBSA) were applied as a direct melt coating on porous cast hemp papers, and the final composite was compressed under three different loads: 0.5 MT, 1.5 MT, and 3.0 MT. To promote sustainable agriculture waste management, we opted to use cast paper made from ground hemp stalks. The formation of the composite structure was examined with scanning electron microscopy (SEM), while surface wetting on the paper side of the laminate was performed to understand structural changes induced by polymer impregnation into the paper layer. Mechanical performance properties were investigated with tensile and peel tests, and suitability for an extended range of temperatures was examined with dynamical mechanical analysis. An increase in compression pressure yielded up to a two-fold improvement in elastic modulus and tensile strength, while thermomechanical analysis revealed that the polymer’s transition into a viscoelastic state significantly affected the laminate’s storage modulus values. Biodegradation was performed in a controlled compost at 58 °C, resulting in full degradation within 40 to 80 days, with PLA and PHA laminates showing 40 and 50 days, respectively. Produced bioplastic laminates have a tremendous potential to replace polyolefin laminates in packaging applications.

Wheat bran addition as potential alternative to control the plasticizer migration into PLA/PBSA blends

Wheat bran (WB) was investigated as potential filler for controlling the plasticizer migration in poly(lactic acid) (PLA)/poly(butylene succinate adipate) (PBSA) binary blends (with 60 wt.% of PLA and 40 wt.% of PBSA). The migration process of three different biobased and biodegradable plasticizers [Triacetin (TA), acetyl tri-n-butyl citrate (ATBC) and oligomeric lactic acid (OLA)] was investigated adding them at a fixed amount of 10 wt.%. TA revealed the greater mass loss over the time as confirmed from the calculation of the diffusion coefficients. The addition of WB in different amount (from 10 to 30 wt.%) revealed its tendency to influence the diffusion process in a manner strictly dependent on its content. The great dimensions of the WB, however, weaken the material suggesting to adopt a preliminary dimensional reduction of the filler to mitigate the negative effect observed on the mechanical properties. From this study emerged the WB potential to be used as filler for controlling the plasticizer migration, thus suggesting a possible valorization of this waste byproduct in biobased and biodegradable materials.

Valorization of Ferulic Acid from Agro-Industrial by-Products for Application in Agriculture.

The use of bioplastic mulch in agriculture has increased dramatically in the last years throughout the world. Nowadays, biodegradable materials for mulching films strive to constitute a reliable and more sustainable alternative to classical materials such as polyethylene (PE). The main challenge is to improve their durability in the soil to meet the required service length for crop farming by using benign and sustainable antioxidant systems. Here, we report the design and fabrication of biodegradable materials based on polybutylene (succinate adipate) (PBSA) for mulching applications, incorporating a fully biobased polymeric antioxidant deriving from ferulic acid, which can be extracted from an industrial by-product. Poly-dihydro (ethylene ferulate) (PHEF) from ferulic acid was synthesized by a two-step polymerization process. It is characterized by improved thermal stability in comparison with ferulic acid monomer and therefore suitable for common industrial processing conditions. Different blends of PBSA and PHEF obtained by melt mixing or by reactive extrusion were prepared and analyzed to understand the effect of the presence of PHEF. The results demonstrate that PHEF, when processed by reactive extrusion, presents a remarkable antioxidant effect, even in comparison with commercial additives, preserving a high level of the mechanical properties of the PBSA matrix without affecting the biodegradable character of the blend.

Evaluating the Ready Biodegradability of Biodegradable Plastics.

Reducing the environmental burden and assessing the safety of plastics are huge global challenges. However, standard test data on the ready biodegradability of plastics are limited. We evaluated the ready biodegradability of 8 biodegradable plastics using Organisation for Economic Co-operation and Development (OECD) test guideline 301F with nonspecific bacteria and examined the effects of prolonging the test duration to a maximum of 90 d. Cellulose used as a potential reference material for plastics was not comparable to the reference material of OECD test guideline 301, but it may be improved by using a test concentration lower than the typical test concentration (100 mg/L). Of the 8 plastics examined, polyamide 4, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), polycaprolactone, and poly(butylene succinate adipate; PBSA) were biodegraded by >60% by day 28 and considered to show ready biodegradability. Poly(3-hydroxybutyrate; PHB), poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid; PHBV), and poly(butylene succinate; PBS) were biodegraded but did not fulfill the ready biodegradability criteria. Because the typical test concentration is considered to have negative effects on biodegradation and calculation of biodegradation percentage, using a lower concentration may result in PHB, PHBV, and PBS fulfilling the ready biodegradability criteria. Poly(d,l-lactide; PLA) was not biodegraded. The biodegradation of PBS and PBSA was noted to vary depending on the used inoculum and/or particle size. For the 7 plastics except PLA, the percentage biodegradation on day 60 was larger than that on day 28, indicating that a longer test period could be useful for evaluating the environmental persistence of plastics. In tests in which the plastics were not biodegraded by day 60, no marked biodegradation was observed by day 90. Environ Toxicol Chem 2021;40:2443-2449. © 2021 SETAC.

Effect of Mineral Fillers on the Mechanical Properties of Commercially Available Biodegradable Polymers.

In the successful transition towards a circular materials economy, the implementation of biobased and biodegradable plastics is a major prerequisite. To prevent the accumulation of plastic material in the open environment, plastic products should be both recyclable and biodegradable. Research and development actions in the past few decades have led to the commercial availability of a number of polymers that fulfil both end-of-life routes. However, these biobased and biodegradable polymers typically have mechanical properties that are not on par with the non-biodegradable plastic products they intend to replace. This can be improved using particulate mineral fillers such as talc, calcium carbonate, kaolin, and mica. This study shows that composites thereof with polybutylene succinate (PBS), polyhydroxybutyrate-hexanoate (PHBH), polybutylene succinate adipate (PBSA), and polybutylene adipate terephthalate (PBAT) as matrix polymers result in plastic materials with mechanical properties ranging from tough elastic towards strong and rigid. It is demonstrated that the balance between the Young’s modulus and the impact resistance for this set of polymer composites is subtle, but a select number of investigated compositions yield a combination of industrially relevant mechanical characteristics. Finally, it is shown that the inclusion of mineral fillers into biodegradable polymers does not negate the microbial disintegration of these polymers, although the nature of the filler does affect the biodegradation rate of the matrix polymer.

16S rRNA Gene Amplicon Sequencing of Microbiota in Polybutylene Succinate Adipate-Packed Denitrification Reactors Used for Water Treatment of Land-Based Recirculating Aquaculture Systems.

Information on the microbiota in polybutylene succinate adipate (PBSA)-packed denitrification reactors is limited. Here, we provide 439,817 high-quality reads of the 16S rRNA gene sequences of microbiota in PBSA-packed denitrification reactors used for land-based recirculating aquaculture. The predominant microorganisms belonged to the following families: Nocardiaceae, Chitinophagaceae, Xanthobacteraceae, Burkholderiaceae, Rhodocyclaceae, Pseudomonadaceae, Rhodanobacteraceae, and Xanthomonadaceae.

Development of PLA-PBSA based biodegradable active film and its application to salmon slices

Abstract Due to negative impacts of non-biodegradable plastic films to the environment, biodegradable packaging materials have become a research hotspot. Novel biodegradable active films based on polylactic acid (PLA) blended with poly (butylene succinate adipate) (PBSA), carvacrol, and thymol were developed. Mechanical properties of films including tensile strength (TS), elongation at break (EAB), optical properties including transmittance (T) and haze (H), barrier properties including water vapor permeability (WVP), oxygen transmission rate (OTR), and releasing rates of active compound from films and antioxidant efficiency of films were investigated to evaluate the films. A shelf life test of salmon slices packed with PLA-PBSA bags (with and without active compound) were carried out. The results showed that PLA-PBSA based films had better mechanical properties than those of similar biodegradable films such as PLA-PHB, and even better than EVOH in terms of two major mechanical properties, TS and EAB. As to active properties, the results also showed a high release of active compound and high antioxidant efficiency of PLA-PBSA films with either carvacrol or thymol. The shelf life test of salmon slices showed the antibacterial and antioxidant properties of the PLA–PBSA films were enhanced when the active compound were released into salmon slices at equilibrium. As a result, spoilage and deterioration of the salmon slices were reduced, which extended the shelf life of salmon slices by 3–4 days during cold storage. Thus, the biodegradable PLA–PBSA films with active compound could prolong shelf life of fisheries products in particular, and food in general.

Molecular and Supramolecular Changes in Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) Copolymer during Degradation in Various Environmental Conditions.

In this paper, the influence of the various degradation conditions, on the molecular and supramolecular structure of polybutylene succinate (PBS) and polybutylene succinate adipate (PBSA) copolymer during degradation is described. The experiment was carried out by the use of injection molded samples and normalized conditions of biodegradation in soil, composting and artificial weathering. Materials were studied by size-exclusion chromatography (SEC) coupled with multiangle laser light scattering (MALLS) detection and wide-angle X-ray diffraction (WAXD). Additionally, the physical and mechanical properties of the samples were determined. The performed experiments clearly show difference impacts of the selected degradation conditions on the macroscopic, supramolecular and molecular parameters of the studied aliphatic polyesters. The structural changes in PBS and PBSA explain the observed changes in the physical and mechanical properties of the obtained injection molded samples.

Improving mechanical properties of cardanol-bonded cellulose diacetate composites by adding polyester resins and glass fiber

We developed advanced cellulose-based resin composites consisting of cardanol-bonded cellulose diacetate (CDA), polyester resins and glass fiber, which have high impact strength and bending strength suitable for durable products. By testing the addition of various polyester resins to the PAA-bonded CDA, we found that poly(butylene succinate adipate) (PBSA), which has flexibility and high compatibility with the PAA-bonded CDA, greatly increased its impact strength. Furthermore, adding glass fiber to the PAA-bonded CDA composites with PBSA enhanced its bending strength and impact strength.

Development of cardanol-bonded cellulose thermoplastics: high productivity achieved in two-step heterogeneous process

We developed a heterogeneous process with low energy consumption to synthesize novel high-strength and heat-resistant cellulose-based bioplastics: cellulose esters bonded with a short chain component (acetic acid) and a long one (3-pentadecylphenoxy acetic acid; PAA), which is a derivative of cardanol, extracted from cashew nut shells. Although we recently showed that PAA-bonded cellulose acetates (cardanol-bonded cellulose resins) exhibit highly practical properties for durable products, they were synthesized in a homogeneous process, which requires large quantities of poor solvents to isolate the resins. In the developed two-step heterogeneous process, the cardanol-bonded cellulose resins are produced without poor solvents. In the first step, cellulose is esterified with limited amounts of the long and short chain components using a selected reaction solvent and catalyst. The resultant intermediate products are adequately swollen in the solvent then efficiently recovered by filtration. In the second step, the short chain component is additionally bonded to attain good thermoplasticity of the final products, which are readily recovered only by distilling a solvent and the remaining short chain component. The solvent usage was reduced by approximately 90 % compared with a homogeneous process, which leads to a large reduction in energy. The produced cardanol-bonded cellulose resins exhibited higher thermoplasticity, elastic modulus, water resistivity, and close heat resistivity compared to that of a homogeneous process. Furthermore, the mechanical and thermal characteristics of the resins were greatly improved by adding a specific polyester, polybutylene succinate adipate, and glass fiber, reaching high-level target properties for durable products.

Polyamide 4 with long-chain fatty acid groups – Suppressing the biodegradability of biodegradable polymers

Polyamide 4 (PA4) is a biodegradable polymer that can be produced from biomass. We found that modifying the terminal group of PA4 with a long-chain fatty acid resulted in the suppression of its biodegradation. PA4 modified with various acyl compounds from acetyl (C2) to stearoyl (C18) chlorides were prepared and used for biodegradation tests. The biodegradation of the PA4s was evaluated using PA-4-degrading bacteria (Pseudomonas sp. ND-11) and activated sludge. The PA4-degrading bacteria grew and formed a clear zone around the colonies on the media containing PA4s with C2, C3, C6, and C10 end groups. On the other hand, PA4s with C12, C14, C16, and C18 end groups were not significantly degraded. Similar results were obtained using activated sludge. These results showed that the biodegradability of PA4 could be controlled by the molecular design of the polymer end group. Blending PA4 with fatty acid-functionalized PA4 decreased its biodegradability depending on the blend ratio. From the results of the contact angle measurements on the PA4 surfaces, it was suggested that the biodegradability was correlated to the hydrophilicity of the polymers. This method of controlling the biodegradability by adding a fatty acid group could be applied to other biodegradable polymers such as poly(butylene succinate adipate)s, e-poly(caprolactone), and poly(lactic acid).

Greenhouse gas emissions from the treatment of household plastic containers and packaging: Replacement with biomass-based materials

The purpose of this study was to quantify the life-cycle greenhouse gas (GHG) emissions reduction that could be achieved by replacement of fossil-derived materials with biodegradable, biomass-based materials for household plastic containers and packaging, considering a variety of their treatment options. The biomass-based materials were 100% polylactide or a combination of polybutylene succinate adipate and polylactide. A scenario analysis was conducted considering alternative recycling methods. Five scenarios were considered: two for existing fossil-derived materials (the current approach in Japan) and the three for biomass-based materials. Production and waste disposal of 1 m(3) of plastic containers and packaging from households was defined as the functional unit. The results showed that replacement of fossil-derived materials with biomass-based materials could reduce life-cycle GHG emissions by 14-20%. Source separation and recycling should be promoted. When the separate collection ratio reached 100%, replacement with biomass-based materials could potentially reduce GHG emissions by 31.9%. Food containers are a priority for replacement, because they alone could reduce GHG emissions by 10%. A recycling system for biomass-based plastics must be carefully designed, considering aspects such as the transition period from fossil-derived plastics to biomass-based plastics.