Mariela Elgegren, A. Donayre, Suyeon Kim, B. Galarreta, J. Nakamatsu
Cat’s claw and aloe vera gel contain active compounds and could be used to enhance the properties of wound dressings. Cat’s claw is known for its anti-inflammatory, anti-arthritic and anti-asthmatic properties; and aloe vera is commonly used for wound healing and skin hydration. In this study, we elaborated microparticles from an emulsion made of alginate solutions with aloe vera gel or cat’s claw extract with ultrasound and tri-dimensional membranes obtained by solvent evaporation. The 27 to 33 µm-thick membranes showed a porous surface on scanning electron microscopy (SEM); the contact angle of water on the membranes increased in hydrophilicity due to the use of aloe vera gel. Furthermore, the presence of aloe vera also improved water absorption in an acetate buffer (pH 5.5) at 37.5 °C. Finally, the presence of cat’s claw extract in the microparticles significantly enhanced radical scavenging in the 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ABTS, decoloration assay, in comparison to tri-dimensional alginate membranes with no active compounds. Alginate films with cat’s claw extract or aloe vera gel could be used as wound dressings materials.
{"title":"Tridimensional Alginate Films with Cat’s Claw (Uncaria tomentosa) Extract or Aloe Vera (Aloe barbadensis) Gel for Potential Use as Wound Dressings","authors":"Mariela Elgegren, A. Donayre, Suyeon Kim, B. Galarreta, J. Nakamatsu","doi":"10.3390/CGPM2020-07225","DOIUrl":"https://doi.org/10.3390/CGPM2020-07225","url":null,"abstract":"Cat’s claw and aloe vera gel contain active compounds and could be used to enhance the properties of wound dressings. Cat’s claw is known for its anti-inflammatory, anti-arthritic and anti-asthmatic properties; and aloe vera is commonly used for wound healing and skin hydration. In this study, we elaborated microparticles from an emulsion made of alginate solutions with aloe vera gel or cat’s claw extract with ultrasound and tri-dimensional membranes obtained by solvent evaporation. The 27 to 33 µm-thick membranes showed a porous surface on scanning electron microscopy (SEM); the contact angle of water on the membranes increased in hydrophilicity due to the use of aloe vera gel. Furthermore, the presence of aloe vera also improved water absorption in an acetate buffer (pH 5.5) at 37.5 °C. Finally, the presence of cat’s claw extract in the microparticles significantly enhanced radical scavenging in the 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ABTS, decoloration assay, in comparison to tri-dimensional alginate membranes with no active compounds. Alginate films with cat’s claw extract or aloe vera gel could be used as wound dressings materials.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78124128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bio-based plastics, i.e., non-synthetic polymers produced from renewable resources are gaining special attention as a feasible solution to the environmental issues caused by concerns regarding the impact of waste plastics. Furthermore, such materials can also represent an alternative to petroleum-derived polymers, due to the scarcity of this raw material in the near future. In the polyhydroxyalkanoates (PHA) family, polyhydroxybutyrate (PHB) was the first to be synthesized and characterized. PHB soon gained great attention from industrial and academic researchers since it can be synthesized from a wide variety of available carbon sources, such as agro-industrial and domestic wastes. The aim of this original research has been the identification of the presence of PHB synthetizing bacteria in some soils in a Moroccan region and the production of the bio-based PHB. In particular, the soils of the argan fields in Taroudant were considered. Taroudant is a southwestern region of Morocco where the argan oil tree Argania spinosa is an endemic and preserved species. Starting from rhizospheric soil samples of an argan crop area, we isolated heat-resistant bacteria and obtained pure cultures from it. These bacteria present intracellular endospores stained by the Schaeffer-Fulton method. The presence of intracellular endospores is a very important starting point to verify the effective production of PHB as a compartmentalized material. Further analyses are currently ongoing to try to extract and characterize PHB granules.
{"title":"PHB Produced by Bacteria Present in the Argan Field Soil: A New Perspective for the Synthesis of the Bio-Based Polymer","authors":"Amina Aragosa, V. Specchia, M. Frigione","doi":"10.3390/CGPM2020-07226","DOIUrl":"https://doi.org/10.3390/CGPM2020-07226","url":null,"abstract":"Bio-based plastics, i.e., non-synthetic polymers produced from renewable resources are gaining special attention as a feasible solution to the environmental issues caused by concerns regarding the impact of waste plastics. Furthermore, such materials can also represent an alternative to petroleum-derived polymers, due to the scarcity of this raw material in the near future. In the polyhydroxyalkanoates (PHA) family, polyhydroxybutyrate (PHB) was the first to be synthesized and characterized. PHB soon gained great attention from industrial and academic researchers since it can be synthesized from a wide variety of available carbon sources, such as agro-industrial and domestic wastes. The aim of this original research has been the identification of the presence of PHB synthetizing bacteria in some soils in a Moroccan region and the production of the bio-based PHB. In particular, the soils of the argan fields in Taroudant were considered. Taroudant is a southwestern region of Morocco where the argan oil tree Argania spinosa is an endemic and preserved species. Starting from rhizospheric soil samples of an argan crop area, we isolated heat-resistant bacteria and obtained pure cultures from it. These bacteria present intracellular endospores stained by the Schaeffer-Fulton method. The presence of intracellular endospores is a very important starting point to verify the effective production of PHB as a compartmentalized material. Further analyses are currently ongoing to try to extract and characterize PHB granules.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77044595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coffee silverskin is one of the byproducts generated by the coffee industry. Although it is not the most burdensome one, because it stands only for ~4.2 wt % of coffee, it seems like an auspicious raw material for industrial processes. Coffee silverskin is characterized by a relatively low moisture content of ~5–7%, so it often does not require quite energy-consuming drying processes. The chemical composition of coffee silverskin, as well as other renewable materials, may be significantly affected by its type and origin, in this case, plant Coffea. Nevertheless, due to high fiber content, it could be considered as exciting material for the manufacturing of wood polymer composites. At the same time, it contains noticeable amounts of proteins, which may provide additional features to polymer composites. However, what is most important is the high content of antioxidants, which could noticeably enhance their lifetime by inhibition of the oxidation reactions. In the presented paper, attempts of coffee silverskin incorporation into different polymer matrices were summarized and discussed. Moreover, potential future trends in this area of research were proposed.
{"title":"Coffee Silverskin as a Potential Bio-Based Antioxidant for Polymer Materials: Brief Review","authors":"A. Hejna","doi":"10.3390/CGPM2020-07220","DOIUrl":"https://doi.org/10.3390/CGPM2020-07220","url":null,"abstract":"Coffee silverskin is one of the byproducts generated by the coffee industry. Although it is not the most burdensome one, because it stands only for ~4.2 wt % of coffee, it seems like an auspicious raw material for industrial processes. Coffee silverskin is characterized by a relatively low moisture content of ~5–7%, so it often does not require quite energy-consuming drying processes. The chemical composition of coffee silverskin, as well as other renewable materials, may be significantly affected by its type and origin, in this case, plant Coffea. Nevertheless, due to high fiber content, it could be considered as exciting material for the manufacturing of wood polymer composites. At the same time, it contains noticeable amounts of proteins, which may provide additional features to polymer composites. However, what is most important is the high content of antioxidants, which could noticeably enhance their lifetime by inhibition of the oxidation reactions. In the presented paper, attempts of coffee silverskin incorporation into different polymer matrices were summarized and discussed. Moreover, potential future trends in this area of research were proposed.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77651008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Tarani, Dimitra Patsiaoura, E. Papadopoulou, E. Pavlidou, K. Chrissafis
The population growth and the limited reservoir of fossil resources have ignited the attention of scientific communities and entrepreneurs to produce alternative products with raw-materials from renewable sources. In this work, proteins derived from the recycling of waste textiles were studied as raw-material in the synthesis of thermosetting polymers of phenolic type (phenol-formaldehyde resins) suitable for use as adhesives in the production of wood-based panels. The physical, thermal, and morphological properties of the thermosetting polymers were investigated. For comparison reasons, a typical phenol-formaldehyde (PF) resin was also presented in this study. In detail, the chemical bonds between raw-materials and PF resins were verified with Fourier Transform Infrared spectroscopy (FTIR). The curing performance and thermal stability of the thermosetting PF resins were studied with Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), respectively. Wood-based panels were prepared and tested at a lab scale following a simulation of the industrial practice. Optical Microscope and Scanning Electron Microscopy (SEM) were applied for the study of the interaction between PF resins and woodchips at the lab scale. It was found that the resins were successfully prepared. The maximum curing temperature of the experimental resins was shifted to higher values than the control PF. According to the TGA results, the protein-based resins seem to lose mass with a lower rate, which denotes that they are more thermally stable than a typical PF resin. It can be concluded that protein from waste textiles can effectively replace part of the petrochemical phenol in the PF resin synthesis, thereby increasing the bio-content of the PF resin and making them more friendly to the environment.
{"title":"A New Textile Economy: Synthesis and Characterization of Phenolic Type Resin with Protein from Waste Textiles Suitable for Wood-Based Panels","authors":"E. Tarani, Dimitra Patsiaoura, E. Papadopoulou, E. Pavlidou, K. Chrissafis","doi":"10.3390/CGPM2020-07222","DOIUrl":"https://doi.org/10.3390/CGPM2020-07222","url":null,"abstract":"The population growth and the limited reservoir of fossil resources have ignited the attention of scientific communities and entrepreneurs to produce alternative products with raw-materials from renewable sources. In this work, proteins derived from the recycling of waste textiles were studied as raw-material in the synthesis of thermosetting polymers of phenolic type (phenol-formaldehyde resins) suitable for use as adhesives in the production of wood-based panels. The physical, thermal, and morphological properties of the thermosetting polymers were investigated. For comparison reasons, a typical phenol-formaldehyde (PF) resin was also presented in this study. In detail, the chemical bonds between raw-materials and PF resins were verified with Fourier Transform Infrared spectroscopy (FTIR). The curing performance and thermal stability of the thermosetting PF resins were studied with Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), respectively. Wood-based panels were prepared and tested at a lab scale following a simulation of the industrial practice. Optical Microscope and Scanning Electron Microscopy (SEM) were applied for the study of the interaction between PF resins and woodchips at the lab scale. It was found that the resins were successfully prepared. The maximum curing temperature of the experimental resins was shifted to higher values than the control PF. According to the TGA results, the protein-based resins seem to lose mass with a lower rate, which denotes that they are more thermally stable than a typical PF resin. It can be concluded that protein from waste textiles can effectively replace part of the petrochemical phenol in the PF resin synthesis, thereby increasing the bio-content of the PF resin and making them more friendly to the environment.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85670344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Donsì, S. Bartolucci, P. Bettotti, F. Carosio, P. Contursi, G. Gentile, M. Scarpa, G. Spigno
The European food sector generates about 250 million tons/yr of by-products and waste, of which around 10% from fruit and vegetable processing, with a heavy environmental burden. The agri-food residues (AFR) contain a significant fraction of cellulose and bioactive compounds (mainly antioxidants), which, if recovered, are high added-value material components. The reduction of cellulose down to nano-sized crystalline structures (nanocellulose, NC) provides versatile building blocks, which self-assemble into new materials with superior performances. Despite wood-derived NC is generally considered a green material, its production process is environmentally unfriendly and its large scale utilization would contribute to deforestation. Therefore, more sustainable sources, such as AFR, are desired. The PANACEA project, within the frame of PRIN 2017 call supported by the Italian Ministry of University and Research, proposes an approach based on the recovery of cellulose and bioactive compounds from AFR, with high yield, at various degrees of hierarchical organization, by cascading different physical and chemical processes of increasing complexity. More specifically, physical processes and microbial digestion are exploited to obtain micro-sized cellulose structures while preserving their bioactivity. Chemical and enzymatic processes are used to isolate, purify and functionalize NC at different levels of hierarchical organization, and to design advanced functional materials such as food ingredients, edible coatings, functional colloids, biocides and flame retardants. The sustainable integrated valorization of AFR is addressed through (i) ad hoc pre-treatment of different AFR (Tomato peels, Wheat straw, Coffee residues, Rice bran, Grape marcs, Orange peels), available all year round and with different composition, (ii) application of proprietary high-pressure homogenization (HPH) techniques to micronize the residues in water and completely disintegrate the vegetable cells, with integrated physical fractionation to recover insoluble fibers, (iii) combination with chemical fractionation or high P/T autohydrolysis, or enzymatic treatments. The fabrication of NC structures with tunable size, crystallinity, and surface properties is important to bridge the gap between the production of cellulose and cellulose hybrids and the final applications and is pursued through (i) the size-reduction of NC, or enzymatic lysis, (ii) functionalization via amination or phosphorylation, or (iii) via physical immobilization or covalent bonding with limonene. The characterization of NC in terms of (i) yields, purity, physicochemical, structural, and functional properties, using a multi-technique approach, is associated to the evaluation of (ii) bio-accessibility (through the simulated digestive process) of bioactive compounds and fibers, (iii) film-forming capacity, (iv) gas-barrier properties, (v) rheological behavior, as well as (vi) energy, water, and reagents consumption
{"title":"A Technology Platform For the Sustainable Recovery and Advanced Use of Nanostructured Cellulose from Agri-Food Residues (PANACEA Project)","authors":"F. Donsì, S. Bartolucci, P. Bettotti, F. Carosio, P. Contursi, G. Gentile, M. Scarpa, G. Spigno","doi":"10.3390/CGPM2020-07212","DOIUrl":"https://doi.org/10.3390/CGPM2020-07212","url":null,"abstract":"The European food sector generates about 250 million tons/yr of by-products and waste, of which around 10% from fruit and vegetable processing, with a heavy environmental burden. \u0000The agri-food residues (AFR) contain a significant fraction of cellulose and bioactive compounds (mainly antioxidants), which, if recovered, are high added-value material components. The reduction of cellulose down to nano-sized crystalline structures (nanocellulose, NC) provides versatile building blocks, which self-assemble into new materials with superior performances. Despite wood-derived NC is generally considered a green material, its production process is environmentally unfriendly and its large scale utilization would contribute to deforestation. Therefore, more sustainable sources, such as AFR, are desired. \u0000The PANACEA project, within the frame of PRIN 2017 call supported by the Italian Ministry of University and Research, proposes an approach based on the recovery of cellulose and bioactive compounds from AFR, with high yield, at various degrees of hierarchical organization, by cascading different physical and chemical processes of increasing complexity. More specifically, physical processes and microbial digestion are exploited to obtain micro-sized cellulose structures while preserving their bioactivity. Chemical and enzymatic processes are used to isolate, purify and functionalize NC at different levels of hierarchical organization, and to design advanced functional materials such as food ingredients, edible coatings, functional colloids, biocides and flame retardants. \u0000The sustainable integrated valorization of AFR is addressed through (i) ad hoc pre-treatment of different AFR (Tomato peels, Wheat straw, Coffee residues, Rice bran, Grape marcs, Orange peels), available all year round and with different composition, (ii) application of proprietary high-pressure homogenization (HPH) techniques to micronize the residues in water and completely disintegrate the vegetable cells, with integrated physical fractionation to recover insoluble fibers, (iii) combination with chemical fractionation or high P/T autohydrolysis, or enzymatic treatments. \u0000The fabrication of NC structures with tunable size, crystallinity, and surface properties is important to bridge the gap between the production of cellulose and cellulose hybrids and the final applications and is pursued through (i) the size-reduction of NC, or enzymatic lysis, (ii) functionalization via amination or phosphorylation, or (iii) via physical immobilization or covalent bonding with limonene. \u0000The characterization of NC in terms of (i) yields, purity, physicochemical, structural, and functional properties, using a multi-technique approach, is associated to the evaluation of (ii) bio-accessibility (through the simulated digestive process) of bioactive compounds and fibers, (iii) film-forming capacity, (iv) gas-barrier properties, (v) rheological behavior, as well as (vi) energy, water, and reagents consumption","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87656067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Hejna, M. Barczewski, P. Kosmela, O. Mysiukiewicz
Over the last years, the trend associated with the incorporation of materials from renewable resources into polymer technology is getting significantly more vital. Researchers are trying to transfer the properties of natural raw materials into the polymer world. Therefore, different natural materials are more often investigated as potential additives for polymers. Such an effect is noted for the coffee industry by-products, such as coffee silverskin. Because of the relatively high contents of compounds showing antioxidant activity, such as caffeine, polyphenols, tannins, or melanoidins, this by-product could be considered not only as a filler, but also as a potential modifier for polymer materials. Its antioxidant activity is comparable to commercially available antioxidants applied in polymer technology. Therefore, in the presented paper, we examined the influence of the coffee silverskin (from 1 to 20 wt%) on the thermal and mechanical performance of polyethylene-based composites. Moreover, materials were subjected to accelerated aging tests in the UV chamber, which revealed that coffee silverskin could inhibit the photodegradation of the polymer matrix. Therefore, this by-product should be considered as an exciting alternative for the conventional lignocellulosic fillers, which could provide additional features to polymer composites.
{"title":"Inhibition of Polymer Photodegradation by Incorporation of Coffee Silverskin","authors":"A. Hejna, M. Barczewski, P. Kosmela, O. Mysiukiewicz","doi":"10.3390/CGPM2020-07219","DOIUrl":"https://doi.org/10.3390/CGPM2020-07219","url":null,"abstract":"Over the last years, the trend associated with the incorporation of materials from renewable resources into polymer technology is getting significantly more vital. Researchers are trying to transfer the properties of natural raw materials into the polymer world. Therefore, different natural materials are more often investigated as potential additives for polymers. Such an effect is noted for the coffee industry by-products, such as coffee silverskin. Because of the relatively high contents of compounds showing antioxidant activity, such as caffeine, polyphenols, tannins, or melanoidins, this by-product could be considered not only as a filler, but also as a potential modifier for polymer materials. Its antioxidant activity is comparable to commercially available antioxidants applied in polymer technology. Therefore, in the presented paper, we examined the influence of the coffee silverskin (from 1 to 20 wt%) on the thermal and mechanical performance of polyethylene-based composites. Moreover, materials were subjected to accelerated aging tests in the UV chamber, which revealed that coffee silverskin could inhibit the photodegradation of the polymer matrix. Therefore, this by-product should be considered as an exciting alternative for the conventional lignocellulosic fillers, which could provide additional features to polymer composites.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80168157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microplastics are formed by the degradation of plastic wastes under the action of physicochemical mechanisms in environment, existing as contaminants of emerging concern in recent years due to their adverse impact on living organisms and the environment. When common polymers are exposed to the environment are adversely affected by solar radiation (primarily ultraviolet (UV) UV-B), which initiates photooxidative degradation leading to polymer chain breakdown, causing though the deterioration of their mechanical properties after an unpredictable time. In the present study, to improve understanding of characteristics and mechanism of microplastics, four of the most widely used polymers covering a wide spectrum of applications, due to their excellent chemical inertness and high processability such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP) and polystyrene (PS) in the form of thin films were exposed to UV radiation at 254 nm with constant temperature for several times. After exposure (5, 10, 20, 30, 45 and 60 days), the films were removed from the chamber and UV irradiation influence was evaluated by using FTIR (Fourier-Transform Infrared) Spectroscopy, DSC (Differential Scanning Calorimetry), XRD (X-Ray Diffraction), Py-GC/MS (Pyrolysis-Gas Chromatography/Mass Spectroscopy), SEM (Scanning Electron Microscopy), while their mechanical properties were also evaluated.
{"title":"Investigation of Surface Alteration of Microplastics by Using UV Irradiation","authors":"N. Ainali, D. Lambropoulou, D. Bikiaris","doi":"10.3390/CGPM2020-07217","DOIUrl":"https://doi.org/10.3390/CGPM2020-07217","url":null,"abstract":"Microplastics are formed by the degradation of plastic wastes under the action of physicochemical mechanisms in environment, existing as contaminants of emerging concern in recent years due to their adverse impact on living organisms and the environment. When common polymers are exposed to the environment are adversely affected by solar radiation (primarily ultraviolet (UV) UV-B), which initiates photooxidative degradation leading to polymer chain breakdown, causing though the deterioration of their mechanical properties after an unpredictable time. In the present study, to improve understanding of characteristics and mechanism of microplastics, four of the most widely used polymers covering a wide spectrum of applications, due to their excellent chemical inertness and high processability such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP) and polystyrene (PS) in the form of thin films were exposed to UV radiation at 254 nm with constant temperature for several times. After exposure (5, 10, 20, 30, 45 and 60 days), the films were removed from the chamber and UV irradiation influence was evaluated by using FTIR (Fourier-Transform Infrared) Spectroscopy, DSC (Differential Scanning Calorimetry), XRD (X-Ray Diffraction), Py-GC/MS (Pyrolysis-Gas Chromatography/Mass Spectroscopy), SEM (Scanning Electron Microscopy), while their mechanical properties were also evaluated.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80261457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anca-Dana Bendrea, L. Cianga, G. Ailiesei, I. Cianga
In the last few years, several fluorescent poly-e-caprolactones [1–3] were designed, synthesized and subsequently used as nanoparticles [1], nanofibers [2] or scaffolds [3] in various prospective bioapplications. [...]
{"title":"Fluorescent EDOT-Functionalized Poly-E-Caprolactone: Synthesis, Photophysical and Self-Assembling Properties in Organic Solvents and Its Serendipitously Noticed Behaviour in Protonated Media","authors":"Anca-Dana Bendrea, L. Cianga, G. Ailiesei, I. Cianga","doi":"10.3390/CGPM2020-07208","DOIUrl":"https://doi.org/10.3390/CGPM2020-07208","url":null,"abstract":"In the last few years, several fluorescent poly-e-caprolactones [1–3] were designed, synthesized and subsequently used as nanoparticles [1], nanofibers [2] or scaffolds [3] in various prospective bioapplications. [...]","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84460203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recently approved restriction on diisocyanates highlights the health and safety issues concerning polyurethane manufacturing and the relevance of developing sustainable insulating polymeric foams. This is particularly challenging for applications where the foam is subjected to high temperatures (>80 °C) and bear loads, such as insulating and bonding material for district heating pipes. As part of a PhD project concerning pre-insulated district heating pipes for the circular economy, polybutylene (PB-1) has been identified as a promising candidate for the application, due to its low thermal conductivity, high-temperature mechanical properties, retention, excellent environmental stress cracking resistance (ESCR) and outstanding creep resistance. It is a recyclable thermoplastic and of non-toxic nature, pre-requisites for circular product development. On the contrary to other polyolefins, PB-1 is reported to strain-harden and has high melt strength, required properties for foaming. The purpose of the study is to assess the foamability of PB-1 through extrusion foaming experiments. A twin-screw extruder was used with varying concentrations of a chemical blowing agent. The obtained samples have been characterised for density, expansion ratio and microstructure. Foams with a volume expansion ratio of 1.8 were achieved. The results confirm the foamability of this polymer. The increase of the die pressure and its contribution to strain hardening were identified as key parameters for successful foaming. Further research will include improving the expansion ratio with a physical blowing agent and mechanical characterization of the foam.
{"title":"Recyclable Insulating Foams for High Temperature Applications","authors":"Lucía Doyle, I. Weidlich","doi":"10.3390/CGPM2020-07200","DOIUrl":"https://doi.org/10.3390/CGPM2020-07200","url":null,"abstract":"The recently approved restriction on diisocyanates highlights the health and safety issues concerning polyurethane manufacturing and the relevance of developing sustainable insulating polymeric foams. This is particularly challenging for applications where the foam is subjected to high temperatures (>80 °C) and bear loads, such as insulating and bonding material for district heating pipes. As part of a PhD project concerning pre-insulated district heating pipes for the circular economy, polybutylene (PB-1) has been identified as a promising candidate for the application, due to its low thermal conductivity, high-temperature mechanical properties, retention, excellent environmental stress cracking resistance (ESCR) and outstanding creep resistance. It is a recyclable thermoplastic and of non-toxic nature, pre-requisites for circular product development. On the contrary to other polyolefins, PB-1 is reported to strain-harden and has high melt strength, required properties for foaming. The purpose of the study is to assess the foamability of PB-1 through extrusion foaming experiments. A twin-screw extruder was used with varying concentrations of a chemical blowing agent. The obtained samples have been characterised for density, expansion ratio and microstructure. Foams with a volume expansion ratio of 1.8 were achieved. The results confirm the foamability of this polymer. The increase of the die pressure and its contribution to strain hardening were identified as key parameters for successful foaming. Further research will include improving the expansion ratio with a physical blowing agent and mechanical characterization of the foam.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85752146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Hejna, Ł. Zedler, P. Kosmela, A. Olszewski, Paulina Burger, K. Formela
The recycling of waste tires is a significant environmental and economic issue. One of the leading recycling routes is the shredding of tires, resulting in the generation of ground tire rubber. This material can be easily introduced into various polymer matrices as a filler, reducing the use of conventionally applied petroleum-based materials. In such cases, it is essential to ensure sufficient interfacial compatibility, which can be achieved by the proper modification of the rubber surface. Different treatments of ground tire rubber aim to activate its surface and introduce functional groups, providing the possibility for interfacial interactions and the incorporation of significant amounts of recycled material. Therefore, in the presented paper, we examined the impact of thermo-mechanical treatment in a twin-screw extruder on the appearance and chemical structure of ground tire rubber. Moreover, for each set of process parameters, the specific mechanical energy required for processing was calculated, providing essential insights for the potential industrial application of the analyzed process. The energy demand should be considered as a very important issue during the development of “greener” processes and materials.
{"title":"Recycling of Waste Rubber by Thermo-Mechanical Treatment in a Twin-Screw Extruder","authors":"A. Hejna, Ł. Zedler, P. Kosmela, A. Olszewski, Paulina Burger, K. Formela","doi":"10.3390/CGPM2020-07195","DOIUrl":"https://doi.org/10.3390/CGPM2020-07195","url":null,"abstract":"The recycling of waste tires is a significant environmental and economic issue. One of the leading recycling routes is the shredding of tires, resulting in the generation of ground tire rubber. This material can be easily introduced into various polymer matrices as a filler, reducing the use of conventionally applied petroleum-based materials. In such cases, it is essential to ensure sufficient interfacial compatibility, which can be achieved by the proper modification of the rubber surface. Different treatments of ground tire rubber aim to activate its surface and introduce functional groups, providing the possibility for interfacial interactions and the incorporation of significant amounts of recycled material. Therefore, in the presented paper, we examined the impact of thermo-mechanical treatment in a twin-screw extruder on the appearance and chemical structure of ground tire rubber. Moreover, for each set of process parameters, the specific mechanical energy required for processing was calculated, providing essential insights for the potential industrial application of the analyzed process. The energy demand should be considered as a very important issue during the development of “greener” processes and materials.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85375077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：