Elena Stoleru, R. Dumitriu, M. Brebu, C. Vasile, A. Enache
Microbial contamination represents an undesirable event in various domains. Bioactive natural compounds possess plenty of health benefits, including antimicrobial, antifungal and antioxidative activity; however, they are chemically unstable and susceptible to oxidative degradation. In this context, encapsulation or immobilization methods play a key role in enhancing efficiency. Therefore, in this paper are presented some results regarding the development of antimicrobial polymeric materials using surface-modification and emulsion-stabilization approaches. Two polymeric substrates, one biodegradable, poly(lactic acid), and one non-biodegradable polyethylene, functionalized by γ-irradiation have been modified with different active compounds in order to obtain bioactive food packaging materials. The bioactive agents (clove essential oil and argan vegetal oil) were incorporated into a biopolymer matrix (chitosan) then immobilized on the surface of the functionalized substrates by a wet-treatment involving carbodiimide chemistry. The resulted materials were physico-chemically characterized in order to evaluate the molecular interactions between the natural bioactive compounds and polymeric matrix, the stability of the immobilized surface layer, and their barrier properties. Antimicrobial and antioxidant activities were also evaluated. Moreover, the surface biofunctionalized polymeric substrates were tested as potential packaging materials for cheese preservation. The obtained materials have demonstrated improved barrier properties, good antioxidant and antimicrobial properties, which lead to a delay of the tested food spoilage.
{"title":"Development of Bioactive Polymeric Materials by Incorporation of Essential/Vegetal Oils into Biopolymer Matrices","authors":"Elena Stoleru, R. Dumitriu, M. Brebu, C. Vasile, A. Enache","doi":"10.3390/CGPM2020-07197","DOIUrl":"https://doi.org/10.3390/CGPM2020-07197","url":null,"abstract":"Microbial contamination represents an undesirable event in various domains. Bioactive natural compounds possess plenty of health benefits, including antimicrobial, antifungal and antioxidative activity; however, they are chemically unstable and susceptible to oxidative degradation. In this context, encapsulation or immobilization methods play a key role in enhancing efficiency. Therefore, in this paper are presented some results regarding the development of antimicrobial polymeric materials using surface-modification and emulsion-stabilization approaches. Two polymeric substrates, one biodegradable, poly(lactic acid), and one non-biodegradable polyethylene, functionalized by γ-irradiation have been modified with different active compounds in order to obtain bioactive food packaging materials. The bioactive agents (clove essential oil and argan vegetal oil) were incorporated into a biopolymer matrix (chitosan) then immobilized on the surface of the functionalized substrates by a wet-treatment involving carbodiimide chemistry. The resulted materials were physico-chemically characterized in order to evaluate the molecular interactions between the natural bioactive compounds and polymeric matrix, the stability of the immobilized surface layer, and their barrier properties. Antimicrobial and antioxidant activities were also evaluated. Moreover, the surface biofunctionalized polymeric substrates were tested as potential packaging materials for cheese preservation. The obtained materials have demonstrated improved barrier properties, good antioxidant and antimicrobial properties, which lead to a delay of the tested food spoilage.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88385639","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}
Polylactic acid (PLA) belongs to the few thermoplastic polymers that are derived from renewable resources such as corn starch or sugar cane. PLA is often used in 3D printing by fused deposition modeling (FDM) since it is relatively easy to print, does not show warping, and can be printed without a closed building chamber. On the other hand, PLA has interesting mechanical properties which are influenced by the printing parameters and geometries. Here we present shape-memory properties of PLA cubes with different infill patterns and percentages. We investigate the material response under defined quasi-static load as well as the possibility to restore the original 3D printed shape. The quasi-static flexural properties are linked to the porosity and the infill structure of the samples under investigation, examined optically and by simulations. Our results underline the importance of designing the infill patterns carefully to develop samples with desired mechanical properties.
{"title":"Shape-Memory Properties of 3D Printed PLA Structures","authors":"A. Ehrmann, Guido Ehrmann","doi":"10.3390/CGPM2020-07198","DOIUrl":"https://doi.org/10.3390/CGPM2020-07198","url":null,"abstract":"Polylactic acid (PLA) belongs to the few thermoplastic polymers that are derived from renewable resources such as corn starch or sugar cane. PLA is often used in 3D printing by fused deposition modeling (FDM) since it is relatively easy to print, does not show warping, and can be printed without a closed building chamber. On the other hand, PLA has interesting mechanical properties which are influenced by the printing parameters and geometries. Here we present shape-memory properties of PLA cubes with different infill patterns and percentages. We investigate the material response under defined quasi-static load as well as the possibility to restore the original 3D printed shape. The quasi-static flexural properties are linked to the porosity and the infill structure of the samples under investigation, examined optically and by simulations. Our results underline the importance of designing the infill patterns carefully to develop samples with desired mechanical properties.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91325113","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}
Plant polyphenols are becoming more and more popular due to their strong antiaging properties. The best researched and largest group of polyphenols are flavonoids. Flavonoids have high antioxidant and pharmacological activities and these properties are closely related to their structure. Certain structural elements of these compounds condition their properties and improve or degrade the activities. As a result of the polymerization of flavonoids, macromolecular compounds showing more favorable properties, such as, for example, bactericidal and antioxidant activity, can be obtained. The aim of this study is to polymerize selected flavonoids (quercetin and rutin) in reaction with a crosslinking compound. Glycerol diglycdyl ether (GDE) causes the crosslinking of quercetin or rutin monomers and the formation of polymeric structures. The study analyzed the thermal stability of monomeric and polymeric flavonoids and their antioxidant activity. Poly(flavonoids) showed greater resistance to oxidation than their monomeric forms. Moreover, poly(quercetin) and poly(rutin) have a greater ability to reduce transition metal ions. Polymeric forms of quercetin and rutin can potentially be effective stabilizers, e.g., for polymeric materials.
{"title":"Polymeric Flavonoids Obtained by Cross-Linking Reaction","authors":"M. Latos‐Brozio, A. Masek","doi":"10.3390/CGPM2020-07194","DOIUrl":"https://doi.org/10.3390/CGPM2020-07194","url":null,"abstract":"Plant polyphenols are becoming more and more popular due to their strong antiaging properties. The best researched and largest group of polyphenols are flavonoids. Flavonoids have high antioxidant and pharmacological activities and these properties are closely related to their structure. Certain structural elements of these compounds condition their properties and improve or degrade the activities. As a result of the polymerization of flavonoids, macromolecular compounds showing more favorable properties, such as, for example, bactericidal and antioxidant activity, can be obtained. The aim of this study is to polymerize selected flavonoids (quercetin and rutin) in reaction with a crosslinking compound. Glycerol diglycdyl ether (GDE) causes the crosslinking of quercetin or rutin monomers and the formation of polymeric structures. The study analyzed the thermal stability of monomeric and polymeric flavonoids and their antioxidant activity. Poly(flavonoids) showed greater resistance to oxidation than their monomeric forms. Moreover, poly(quercetin) and poly(rutin) have a greater ability to reduce transition metal ions. Polymeric forms of quercetin and rutin can potentially be effective stabilizers, e.g., for polymeric materials.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79071642","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}
J. Antunes, T. Tavares, N. Homem, M. A. Teixeira, M. T. P. Amorim, H. Felgueiras
Chronic wounds (CW) have numerous entry ways for pathogen invasion and prosperity, damaging host tissue and hindering tissue remodeling. Essential oils exert quick and efficient antimicrobial (AM) action, unlikely to induce bacterial resistance. Cajeput oil (CJO) has strong AM properties, namely against Staphylococcus aureus and Pseudomonas aeruginosa. Chitosan (CS) is a natural and biodegradable cationic polysaccharide, also widely known for its AM features. CS and poly(vinyl alcohol) (PVA) films were prepared (ratio 30/70; 9 wt%) by solvent casting and phase inversion method. Films’ thermal stability and chemical composition data reinforce polymer blending. Films were supplemented with 1 and 10 wt% of CJO in relation to total polymeric mass. Loaded films were 23 and 57% thicker, respectively, than the unloaded films. Degree of swelling and porosity also increased, particularly with 10 wt% CJO. AM testing revealed that CS films alone were effective against both bacteria, eradicating all P. aeruginosa within the hour (*** p < 0.001). Still, loaded CS/PVA films showed improved AM traits, being significantly more efficient than unloaded films right after 2 h of contact. This study is the first proof of concept that CJO can be dispersed into CS/PVA films and show bactericidal effects, particularly against P. aeruginosa, this way opening new avenues for CW therapeutics.
慢性伤口有多种进入途径，病原体侵入和繁荣，破坏宿主组织，阻碍组织重塑。精油发挥快速有效的抗菌(AM)作用，不太可能引起细菌耐药性。菜油(CJO)具有很强的抗AM特性，即抗金黄色葡萄球菌和铜绿假单胞菌。壳聚糖(CS)是一种天然的、可生物降解的阳离子多糖，也因其AM特性而广为人知。制备CS和聚乙烯醇(PVA)薄膜(比例为30/70;9wt %)通过溶剂铸造和相转化法。薄膜的热稳定性和化学成分数据加强了聚合物的共混。在薄膜中添加1 wt%和10 wt%的CJO(相对于总聚合物质量)。加载膜比未加载膜分别厚23%和57%。膨胀和孔隙度也有所增加，特别是当CJO达到10%时。AM测试显示单独CS膜对这两种细菌都有效，在1小时内根除所有铜绿假单胞菌(*** p < 0.001)。尽管如此，加载后的CS/PVA薄膜表现出改善的增材制造特性，在接触2小时后，其效率明显高于未加载的薄膜。这项研究首次证明了CJO可以分散到CS/PVA薄膜中并显示出杀菌效果，特别是对铜绿假单胞菌，这为CW治疗开辟了新的途径。
{"title":"Combinatory Action of Chitosan-Based Blended Films and Loaded Cajeput Oil Against Staphylococcus Aureus and Pseudomonas Aeruginosa-Mediated Infections","authors":"J. Antunes, T. Tavares, N. Homem, M. A. Teixeira, M. T. P. Amorim, H. Felgueiras","doi":"10.3390/CGPM2020-07188","DOIUrl":"https://doi.org/10.3390/CGPM2020-07188","url":null,"abstract":"Chronic wounds (CW) have numerous entry ways for pathogen invasion and prosperity, damaging host tissue and hindering tissue remodeling. Essential oils exert quick and efficient antimicrobial (AM) action, unlikely to induce bacterial resistance. Cajeput oil (CJO) has strong AM properties, namely against Staphylococcus aureus and Pseudomonas aeruginosa. Chitosan (CS) is a natural and biodegradable cationic polysaccharide, also widely known for its AM features. CS and poly(vinyl alcohol) (PVA) films were prepared (ratio 30/70; 9 wt%) by solvent casting and phase inversion method. Films’ thermal stability and chemical composition data reinforce polymer blending. Films were supplemented with 1 and 10 wt% of CJO in relation to total polymeric mass. Loaded films were 23 and 57% thicker, respectively, than the unloaded films. Degree of swelling and porosity also increased, particularly with 10 wt% CJO. AM testing revealed that CS films alone were effective against both bacteria, eradicating all P. aeruginosa within the hour (*** p < 0.001). Still, loaded CS/PVA films showed improved AM traits, being significantly more efficient than unloaded films right after 2 h of contact. This study is the first proof of concept that CJO can be dispersed into CS/PVA films and show bactericidal effects, particularly against P. aeruginosa, this way opening new avenues for CW therapeutics.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88675521","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. Beltrán, M. Arrieta, E. Moreno, G. Gaspar, L. M. Muneta, Ruth Carrasco-Gallego, Susana Yáñez, David Hidalgo-Carvajal, M. U. Orden, J. Urreaga
3D printing PLA wastes were recovered from a well-known reference grade and from different sources. The recovered wastes were subjected to an energic washing step and then reprocessed into films by melt-extrusion, followed by compression molding to simulate the industrial processing conditions. The obtained materials were characterized and the optical, structural, thermal and crystallization behavior are reported. The mechanical recycling process leads to an increase of the crystallinity and a decrease of the intrinsic viscosity of the formulations, particularly in the sample based on blends of different 3D-PLA wastes. Moreover, the obtained films were disintegrated under composting conditions in less than one month and it was observed that recycled materials degrade somewhat faster than the starting 3D-PLA filament, as a consequence of the presence of shorter polymer chains. Finally, to increase the molecular weight of the recycled materials, the 3D-PLA wastes were submitted to a solid-state polymerization process at 110, 120, and 130 °C, observing that the recycled 3D-wastes materials based on a well-known reference grade experiences an improvement of the intrinsic viscosity, while that coming from different sources showed no significant changes. Thus, the results show that 3D printing PLA products provides an ideal environment for the implementation of distributed recycling program, in which wastes coming from well-known PLA grades can successfully be processed in films with good overall performance.
{"title":"Technical Evaluation of Mechanical Recycling of PLA 3D Printing Wastes","authors":"F. Beltrán, M. Arrieta, E. Moreno, G. Gaspar, L. M. Muneta, Ruth Carrasco-Gallego, Susana Yáñez, David Hidalgo-Carvajal, M. U. Orden, J. Urreaga","doi":"10.3390/CGPM2020-07187","DOIUrl":"https://doi.org/10.3390/CGPM2020-07187","url":null,"abstract":"3D printing PLA wastes were recovered from a well-known reference grade and from different sources. The recovered wastes were subjected to an energic washing step and then reprocessed into films by melt-extrusion, followed by compression molding to simulate the industrial processing conditions. The obtained materials were characterized and the optical, structural, thermal and crystallization behavior are reported. The mechanical recycling process leads to an increase of the crystallinity and a decrease of the intrinsic viscosity of the formulations, particularly in the sample based on blends of different 3D-PLA wastes. Moreover, the obtained films were disintegrated under composting conditions in less than one month and it was observed that recycled materials degrade somewhat faster than the starting 3D-PLA filament, as a consequence of the presence of shorter polymer chains. Finally, to increase the molecular weight of the recycled materials, the 3D-PLA wastes were submitted to a solid-state polymerization process at 110, 120, and 130 °C, observing that the recycled 3D-wastes materials based on a well-known reference grade experiences an improvement of the intrinsic viscosity, while that coming from different sources showed no significant changes. Thus, the results show that 3D printing PLA products provides an ideal environment for the implementation of distributed recycling program, in which wastes coming from well-known PLA grades can successfully be processed in films with good overall performance.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"213 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85874976","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}
: It has been estimated that more than 8.3 billion tonnes of plastics have been produced 12 over the past decades and about 60 % of plastics have ended up either in landfills or in the natural 13 environment. With the rapid growth of consumerism, research on innovative starting materials for 14 preparation of polymers may help to reduce the negative impact of petroleum-based plastic 15 materials on the global ecosystem and on animal and human health. Therefore, photochemical 16 thiol-ene coupling reaction of squalene was performed to obtain thiol functional groups. Then, 17 hexathiolated squalene was used as a cross-linker in UV curing reactions with acrylated epoxidized 18 soybean oil. Two photoinitiators, 2-hydroxy-2-methylpropiophenone and ethylphenyl 19 (2,4,6-trimethylbenzoyl) phosphinate, were tested in different quantities. Rheological properties of 20 compositions were monitored by real time photorheometry. The obtained polymers were 21 characterized by differential scanning calorimetry and thermogravimetry. Polymers possessed 22 higher storage modulus and thermal characteristics due to the higher yield of insoluble fraction when ethylphenyl (2,4,6-trimethylbenzoyl) phosphinate was used as photoinitiator.
{"title":"Fully Bio-Based Polymers Derived from Acrylated Epoxidized Soybean Oil by Thiol-ene Reaction","authors":"Sigita Grauzeliene, Deimantė Valaitytė, Jolita Ostrauskaite, À. Serra","doi":"10.3390/CGPM2020-07177","DOIUrl":"https://doi.org/10.3390/CGPM2020-07177","url":null,"abstract":": It has been estimated that more than 8.3 billion tonnes of plastics have been produced 12 over the past decades and about 60 % of plastics have ended up either in landfills or in the natural 13 environment. With the rapid growth of consumerism, research on innovative starting materials for 14 preparation of polymers may help to reduce the negative impact of petroleum-based plastic 15 materials on the global ecosystem and on animal and human health. Therefore, photochemical 16 thiol-ene coupling reaction of squalene was performed to obtain thiol functional groups. Then, 17 hexathiolated squalene was used as a cross-linker in UV curing reactions with acrylated epoxidized 18 soybean oil. Two photoinitiators, 2-hydroxy-2-methylpropiophenone and ethylphenyl 19 (2,4,6-trimethylbenzoyl) phosphinate, were tested in different quantities. Rheological properties of 20 compositions were monitored by real time photorheometry. The obtained polymers were 21 characterized by differential scanning calorimetry and thermogravimetry. Polymers possessed 22 higher storage modulus and thermal characteristics due to the higher yield of insoluble fraction when ethylphenyl (2,4,6-trimethylbenzoyl) phosphinate was used as photoinitiator.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83847005","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}
and changes in the chemical composition of the seed coat with photoelec-tron spectroscopy seed Plasma also the dynamics of the water uptake of seeds. The XPS anal-ysis changes on seed surface, depending on the mode of plasma exposure: time-dependent plasma
{"title":"Bio-Polymers in the World of Plasma: Effects of Cold Plasma on Seed Surface","authors":"Pia Starič, I. Junkar, K. Vogel-Mikuš, M. Mozetič","doi":"10.3390/CGPM2020-07176","DOIUrl":"https://doi.org/10.3390/CGPM2020-07176","url":null,"abstract":"and changes in the chemical composition of the seed coat with photoelec-tron spectroscopy seed Plasma also the dynamics of the water uptake of seeds. The XPS anal-ysis changes on seed surface, depending on the mode of plasma exposure: time-dependent plasma","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84304931","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}
N. Homem, Catarina S Miranda, J. Antunes, M. T. P. Amorim, H. Felgueiras
Problems associated with microbial resistance to antibiotics are growing due to their overuse. In this scenario, plant extracts such as the propolis extract (PE) have been considered as potential alternatives to antibiotics in the treatment of infected wounds, due to its antimicrobial properties and ability to induce tissue regeneration. To improve the long-term effectiveness of PE in wound healing, polymeric films composed of biodegradable and biocompatible polymers are being engineered as delivery vehicles. Here, sodium alginate/gelatin (SA/GN) films containing PE were prepared via a simple, green process of solvent casting/phase inversion technique, followed by crosslinking with calcium chloride (CaCl2) solutions. The minimum inhibitory concentration (MIC) of PE was established as 0.338 mg/mL for Staphylococcus aureus and 1.353 mg/mL for Pseudomonas aeruginosa, the most prevalent bacteria in infected wounds. The PE was incorporated within the polymeric films before (blended with the polymeric solution) and after (immobilization via physisorption) their production. Flexible, highly hydrated SA/GN/PE films were obtained, and their antibacterial activity was assessed via agar diffusion and killing time kinetics examinations. Data confirmed the modified films effectiveness to fight bacterial infections caused by S. aureus and P. aeruginosa and their ability to be applied in the treatment of infected wounds.
{"title":"Modification of Ca2+-crosslinked Sodium Alginate/Gelatin Films with Propolis for an Improved Antimicrobial Action","authors":"N. Homem, Catarina S Miranda, J. Antunes, M. T. P. Amorim, H. Felgueiras","doi":"10.3390/CGPM2020-07180","DOIUrl":"https://doi.org/10.3390/CGPM2020-07180","url":null,"abstract":"Problems associated with microbial resistance to antibiotics are growing due to their overuse. In this scenario, plant extracts such as the propolis extract (PE) have been considered as potential alternatives to antibiotics in the treatment of infected wounds, due to its antimicrobial properties and ability to induce tissue regeneration. To improve the long-term effectiveness of PE in wound healing, polymeric films composed of biodegradable and biocompatible polymers are being engineered as delivery vehicles. Here, sodium alginate/gelatin (SA/GN) films containing PE were prepared via a simple, green process of solvent casting/phase inversion technique, followed by crosslinking with calcium chloride (CaCl2) solutions. The minimum inhibitory concentration (MIC) of PE was established as 0.338 mg/mL for Staphylococcus aureus and 1.353 mg/mL for Pseudomonas aeruginosa, the most prevalent bacteria in infected wounds. The PE was incorporated within the polymeric films before (blended with the polymeric solution) and after (immobilization via physisorption) their production. Flexible, highly hydrated SA/GN/PE films were obtained, and their antibacterial activity was assessed via agar diffusion and killing time kinetics examinations. Data confirmed the modified films effectiveness to fight bacterial infections caused by S. aureus and P. aeruginosa and their ability to be applied in the treatment of infected wounds.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72954756","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}
Nowadays, polymers used in technical applications are still obtained from petrochemicals, despite the more critical reviews from society. In this work, novel nanodielectrics based on renewable resources were developed. For this purpose, poly(2-oxazoline)s (POx), which can be referred to as pseudo-polyamides, were synthesized from renewable resources and compared with commercially available Nylon 12, which is derived from petrochemicals. The monomers 2-nonyl-2-oxazoline and 2-dec-9′-enyl-2-oxazoline were synthesized from coconut oil and castor oil in solvent-free syntheses according to the Henkel Patent; the corresponding copoly(2-oxazoline)s were synthesized in an energy-efficient fashion in microwave reactors under autoclave conditions. Both types of polyamides (two variations: POx and Nylon 12) were filled with inorganic nanoparticles (four variations: no filler, submicro-scaled BN, nano- and micro-scaled AlN as well as a mixture of nano- and micro-scaled AlN and submicro-scaled BN) and/or expanding monomers, namely spiroorthoesters (three variations: 0, 15, and 30 wt.-%), yielding a 2 × 4 × 3 = 24-membered material library. All polymers were crosslinked according to a newly developed thermally-initiated dual/bi-stage curing system. Intense physicochemical and dielectric characterization revealed that the relative volume expansion was in the range of 0.46 to 2.48 vol.-% for the Nylon 12 samples and in the range of 1.39 to 7.69 vol.-% for the POx samples. Hence, the formation micro-cracks or micro-voids during curing is significantly reduced. The dielectric measurements show competitive dielectric behavior of the “green” POx samples in comparison with the fossil-based Nylon 12 samples at a frequency of 40 Hz.
{"title":"Dual/Bi-Stage Curing of Nanocomposites from Renewable Resources upon Volumetric Expansion","authors":"Fabio Blaschke, P. Marx, F. Wiesbrock","doi":"10.3390/CGPM2020-07161","DOIUrl":"https://doi.org/10.3390/CGPM2020-07161","url":null,"abstract":"Nowadays, polymers used in technical applications are still obtained from petrochemicals, despite the more critical reviews from society. In this work, novel nanodielectrics based on renewable resources were developed. For this purpose, poly(2-oxazoline)s (POx), which can be referred to as pseudo-polyamides, were synthesized from renewable resources and compared with commercially available Nylon 12, which is derived from petrochemicals. The monomers 2-nonyl-2-oxazoline and 2-dec-9′-enyl-2-oxazoline were synthesized from coconut oil and castor oil in solvent-free syntheses according to the Henkel Patent; the corresponding copoly(2-oxazoline)s were synthesized in an energy-efficient fashion in microwave reactors under autoclave conditions. Both types of polyamides (two variations: POx and Nylon 12) were filled with inorganic nanoparticles (four variations: no filler, submicro-scaled BN, nano- and micro-scaled AlN as well as a mixture of nano- and micro-scaled AlN and submicro-scaled BN) and/or expanding monomers, namely spiroorthoesters (three variations: 0, 15, and 30 wt.-%), yielding a 2 × 4 × 3 = 24-membered material library. All polymers were crosslinked according to a newly developed thermally-initiated dual/bi-stage curing system. Intense physicochemical and dielectric characterization revealed that the relative volume expansion was in the range of 0.46 to 2.48 vol.-% for the Nylon 12 samples and in the range of 1.39 to 7.69 vol.-% for the POx samples. Hence, the formation micro-cracks or micro-voids during curing is significantly reduced. The dielectric measurements show competitive dielectric behavior of the “green” POx samples in comparison with the fossil-based Nylon 12 samples at a frequency of 40 Hz.","PeriodicalId":20633,"journal":{"name":"Proceedings of The First International Conference on “Green” Polymer Materials 2020","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90842144","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：