Improvement in mechanical properties of polyurethane‐urea nanocomposites by using modified SiO<sub>2</sub> nanoparticles

Yarmohammadi, Masoud; Adeli, Alireza Khalaf; Pedram, Mona Zamani; Shahidzadeh, Mansour; Pirouzfar, Vahid

doi:10.1002/app.46707

Cited by 9 publications

(4 citation statements)

References 53 publications

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“…Foam density increased by 27% when the AgPL NPs content was 0.25% compared with the reference PUF-0 (Figure a). Incorporation of NPs chemically cross-linked with polyurethane has been described to improve the mechanical performance of the foams . In this study, the addition of AgPL NPs to the foams resulted in a 40% increase of their compression modulus, i.e., from 55 kPa for the reference PUF-0 to 78 and 77 kPa for PUF-0.20%NP and PUF-0.25%NP, respectively (Figure b).…”

Section: Resultsmentioning

confidence: 72%

Antibacterial Polyurethane Foams with Incorporated Lignin-Capped Silver Nanoparticles for Chronic Wound Treatment

Morena

Stefanov

Ivanova

et al. 2020

Ind. Eng. Chem. Res.

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Lignin-capped silver nanoparticles were incorporated in situ into polyurethane foams during their polymerization to obtain multifunctional materials suitable for chronic wound dressing. Lignin with increased phenolic content, achieved through the enzymatic grafting of natural phenolic compounds, played the dual role of a silver reducing agent in the synthesis of the lignin-capped silver nanoparticles and as a nanoformulated polyol additive in the polyurethane composition able to react with isocyanate. The nanoparticles-embedded polyurethane foams showed over 4 and 5 logs bacterial growth reduction against the Gram-positive S. aureus and the Gram-negative P. aeruginosa, respectively, attributed to both the direct contact- and release-killing mechanisms. The swelling properties of the foams, related to their capacity to remove the excess of wound exudates containing deleterious oxidative species and enzymes, varied from 585 to 1145% as a function of the content of nanoparticles. Overall, the physicomechanical and antibacterial properties of the foams, together with their biocompatibility and sustained release of silver, make these multifunctional materials suitable candidates for chronic wound dressings.

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Section: Resultsmentioning

confidence: 72%

Antibacterial Polyurethane Foams with Incorporated Lignin-Capped Silver Nanoparticles for Chronic Wound Treatment

Morena

Stefanov

Ivanova

et al. 2020

Ind. Eng. Chem. Res.

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“…38 Considerably, the fabricated elastomer via their suggested method could be reshaped and reprocessed by room-temperature compression through rearrangements of the cross-linked. 38 In continuous to our previous studies on self-healing materials [39][40][41][42][43] and polymer properties, 25,44 self-heal epoxy coatings have been prepared using disulfide metathesis reaction. In this regard, an epoxy terminated chain extender with capability of performing reversible reaction has been synthesized via functionalization of 3,3 0 -dithiodipropionic acid (DTPA) with bisphenol A diglycidyl ether (DGEBA).…”

Section: Introductionmentioning

confidence: 99%

“…In continuous to our previous studies on self‐healing materials 39–43 and polymer properties, 25,44 self‐heal epoxy coatings have been prepared using disulfide metathesis reaction. In this regard, an epoxy terminated chain extender with capability of performing reversible reaction has been synthesized via functionalization of 3,3′‐dithiodipropionic acid (DTPA) with bisphenol A diglycidyl ether (DGEBA).…”

Section: Introductionmentioning

confidence: 99%

Thermal induced intrinsic self‐healing in epoxy based elastomer coatings provided by disulfide metathesis reactions

Eidi

Pedram

2022

J of Applied Polymer Sci

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Self-heal epoxy coatings have been prepared using sulfur-sulfur metathesis reaction as an intrinsic method for inducing self-healing property. Inducing of the self-healing property was carried out via insertion of the 3,3 0 -dithiodipropionic acid as chain extender functionalized with bisphenol A diglycidyl ether.According to the results, the prepared coatings were capable to recover their mechanical properties after damage and heal their surface as well. Noticeably, the healing yield of the coatings was about 43% and 76% for the samples containing 0.5 and 1.0 equivalents of chain extender, respectively. Furthermore, the mechanical properties of the self-heal coating were modified in the presence of the disulfide bonds from 0.22 MPa to 1.25 MPa. Regarding to the increment of the crosslinking density due to the presence of the sulfur containing chain expender, the average molecular weights between crosslinkings was reduced from 43.75 Â 10 3 g mol À1 in epoxy sample to 4.61 Â 10 3 g mol À1 in sulfur containing sample. The proposed facilitate method for inducing the self-healing property make it applicable to a wide range of epoxy coatings.

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“…Incorporation of NPs chemically cross-linked with polyurethane has been described to improve the mechanical performance of the foams. 235 In this study, the addition of AgPheLigNPs to the foams resulted in 40 % increase of their compression modulus, i. e. from 55 kPa for the reference PUF-0 to 78 kPa for PUF-0.20%NP and PUF-0.25%NP (Figure 38b). The results obtained from mechanical characterization of the PUFs suggested that the NPs are part of their structure and the lignin from the NPs may be covalently crosslinked with the polyols.…”

Section: Structural and Mechanical Characterization Of Pufsmentioning

confidence: 59%

Lingnin-based nanoparticles with antibacterial properties and their nanocomposite materials for wound healing

Morena Gatius

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(English) Lignocellulosic biomass is an abundant renewable resource considered a suitable carbon raw material for the synthesis of chemicals and as an alternative to fossil fuels energy supply source. Cellulose, hemicellulose, and lignin are the primary components of lignocellulosic biomass, among which lignin, the most abundant aromatic molecule on earth, represents from 15 to 30 % of its dry mass in woody plants. Lignin has been traditionally considered a low value by-product from paper manufacturing. Around 70 million tons of lignin are generated annually from the pulp and paper industry, whereof only 2–5 % is reused in its macromolecular form. Its underutilization is mainly caused by its heterogeneous molecular structure, which highly depends on the extraction and purification methods, and its low compatibility with polymeric matrices in composite production. In recent years, the potential of lignin for the synthesis of value-added materials has been considered in various fields. Lignin features multiple functionalities, including aromatic and aliphatic hydroxyl groups, providing antibacterial, antioxidant, and ultraviolet (UV)-blocking capacities, in addition to carboxylic, carbonyl, and methoxyl groups. Nanotransformation of lignin yields nano-entities with higher reactivity compared to their bulk counterparts, which inclusion in composites endows them with enhanced mechanical properties and bioactivities. Nanoformulation of lignin is an emerging valorization approach, yielding lignin nanoparticles (LigNPs) that have been used as mechanical reinforcement in polymeric matrices, as UV absorbents, as antibacterial and antioxidant agents in food packaging, and as carriers for drug delivery. The increasing interest in LigNPs is reflected in the numerous recent reviews addressing the bioactivities of macromolecular lignin in biomedical applications, the methods for the synthesis of LigNPs and their different applications, and the combination of lignin with other materials or actives to obtain hybrid nanocomposites. In light of the rapid surge of antimicrobial resistance (AMR), driven by the misuse and overuse of antibiotics, research has been focused on developing novel antimicrobials for substituting conventional antibiotics. The use of LigNPs as antibacterial agents is a suitable alternative to traditional antibiotics owing to their antibacterial properties and their biocompatibility, coupled to additional bioactivities such as antioxidant and UV-blocking. The present thesis aims to develop novel antibiotic-free, lignin-based NPs with antibacterial properties for biomedical applications. To achieve this, different hybrid LigNPs have been designed by combining the biopolymer with metals, metalloids, and natural phenolic compounds. The antibacterial properties against medically relevant strains, the biocompatibility toward human cells, and the mechanism of action of the NPs were studied. Such particles were used as active and structural elements in materials for biomedical uses (polyurethane foams and hydrogels), especially for chronic wound treatment. The potential of these materials as wound dressings was assessed by measuring their antibacterial and antioxidant capacity, ability to inhibit deleterious wound enzymes, and capacity to absorb exudates. (Català) La biomassa lignocel·lulòsica és un recurs renovable abundant considerat com una font de carboni adequada per a la síntesis productes químics i com a alternativa als combustibles fòssils per proveir energia. La cel·lulosa, l’hemicel·lulosa i la lignina són els components primaris de la biomassa lignocel·lulòsica. La lignina és la molècula aromàtica més abundant al planeta i representa un 15–30 % del pes sec en les plantes llenyoses. Tradicionalment, la lignina s’ha considerat un subproducte de baix valor resultant de la indústria de la pasta i del paper. Cada any es generen al voltant de 70 milions de tones de lignina com a conseqüència de l’activitat de la indústria paperera, i només un 2–5 % es reutilitza en la seva forma macromolecular. La seva infrautilització és causada principalment per l’heterogeneïtat de la seva estructura molecular, la qual varia en funció dels mètodes d’extracció i de purificació, i per la seva baixa compatibilitat amb matrius polimèriques en la producció de compòsits. En els últims anys, el potencial de la lignina per sintetitzar materials de valor afegit s’ha considerat en diferents camps d’aplicació. La lignina té diversos grups funcionals, d’entre els quals destaquen els grups hidroxils aromàtics i alifàtics, responsables d’aportar propietats antibacterianes, antioxidants i capacitat de bloquejar la penetració dels rajos UV, juntament amb els grups carboxil, carbonil i metoxil. La nanotransformació de la lignina resulta en nanopartícules (NPs) amb una reactivitat més elevada que el seu homòleg macroscòpic, i la seva incorporació en compòsits suposa una millora de les propietats mecàniques i de les bioactivitats. La nanoformulació és una via emergent per valoritzar la lignina en la qual les nanopartícules de lignina (LigNPs) resultants ja s’han utilitzat com a reforç mecànic en matrius polimèriques, com a absorbents de la radiació UV, com a agents antioxidants i antibacterians en envasos d’ús alimentari i com a portadors per al lliurament de fàrmacs. El creixent interès en les LigNPs es reflecteix en els nombrosos articles de revisió sobre les bioactivitats de lignina macromolecular en aplicacions biomèdiques, els mètodes per a la síntesi de LigNPsi les seves diferents aplicacions, i la combinació de lignina amb altres materials o agents actius per obtenir nanocompòsis híbrids. Considerant el ràpid augment de la resistència antimicrobiana (AMR), impulsat per l’excessiu i incorrecte ús d'antibiòtics, el focus de la recerca s'ha centrat en el desenvolupament de nous agents antimicrobians per substituir els antibiòtics convencionals. L'ús de les LigNPs com a agents antibacterians és una alternativa adequada als antibiòtics tradicionals gràcies a les seves propietats antibacterianes i la seva biocompatibilitat, juntament amb altres bioactivitats com l’antioxidant i la capacitat de bloquejar els rajos UV. Aquesta tesi pretén desenvolupar noves NPs basades en lignina sense antibiòtics i amb propietats antibacterianes per a aplicacions biomèdiques. Per aconseguir-ho, diferents LigNPs híbrides han estat dissenyades combinant la lignina amb metalls, metal·loides i compostos fenòlics naturals, i les seves propietats antibacterianes, la seva biocompatibilitat cap a les cèl·lules humanes i el seu mecanisme d'acció ha estat estudiat. Aquestes partícules s’han utilitzat com a elements actius i estructurals en materials per a usos biomèdics (escumes de poliuretà i hidrogels), concretament pel tractament de ferides cròniques. El potencial d'aquests materials per al tractament de ferides es va avaluar mesurant la seva capacitat antibacteriana i antioxidant, l’habilitat d'inhibir certs enzims perjudicials present en les ferides i la capacitat d'absorbir exsudats.

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Improvement in mechanical properties of polyurethane‐urea nanocomposites by using modified SiO₂ nanoparticles

Cited by 9 publications

References 53 publications

Antibacterial Polyurethane Foams with Incorporated Lignin-Capped Silver Nanoparticles for Chronic Wound Treatment

Antibacterial Polyurethane Foams with Incorporated Lignin-Capped Silver Nanoparticles for Chronic Wound Treatment

Thermal induced intrinsic self‐healing in epoxy based elastomer coatings provided by disulfide metathesis reactions

Lingnin-based nanoparticles with antibacterial properties and their nanocomposite materials for wound healing

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Improvement in mechanical properties of polyurethane‐urea nanocomposites by using modified SiO2 nanoparticles

Cited by 9 publications

References 53 publications

Antibacterial Polyurethane Foams with Incorporated Lignin-Capped Silver Nanoparticles for Chronic Wound Treatment

Antibacterial Polyurethane Foams with Incorporated Lignin-Capped Silver Nanoparticles for Chronic Wound Treatment

Thermal induced intrinsic self‐healing in epoxy based elastomer coatings provided by disulfide metathesis reactions

Lingnin-based nanoparticles with antibacterial properties and their nanocomposite materials for wound healing

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Improvement in mechanical properties of polyurethane‐urea nanocomposites by using modified SiO₂ nanoparticles