Temat: poly(lactic acid) - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Polylactide: from Synthesis and Modification to Final Properties
Autorzy:: Aniśko, Joanna
Barczewski, Mateusz
Tematy:: modification
PLA
polylactide
poly(lactic acid)
composite; Pokaż więcej
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2123282.pdf Link otwiera się w nowym oknie
Opis:: The article reports ways and trends in polylactide (PLA) modification methods concerning literature data. The paper consists of two parts and presents the process of polylactide production, and the connection of changes in its properties with the polymer structure obtained thanks to appropriate process conditions and methods of its final polymer properties improvement. Discussing both the most advantageous properties and disadvantages, the possibilities of increasing the scope of its applicability in reference to selected modification methods were presented and discussed. The presented research results related to various modification methods arrange the knowledge from the discussed scope, indicating the best possible effects and limitations. The most considerable emphasis is on the methods and results obtained from heterogeneous nucleation and incorporating various fillers in the PLA matrix. The other methods, like applying chemical interaction methods (crosslinking, using chain extenders), development of polymer blends, copolymerization, and plasticization, are presented synthetically. In summary, the review present and organizes the achievements in the possibility of modifying the most prospective biodegradable polymer, which is PLA.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Permeability of N, P, K-fertilizer nutrient and water vapor through PLA, PLA/PS, and PLA/HA membranes
Autorzy:: Deng, Xiaonan
Ye, Sihong
Liu, Kun
Li, Changfeng
Liu, Fangzhi
Yan, Xiaoming
Tematy:: Permeability
polymer-coated fertilizer
mathematical model
poly lactic acid
membrane; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/777994.pdf Link otwiera się w nowym oknie
Opis:: To collect permeability data and establish its database of fertilizer nutrients and water vapor through different polymer membranes for the development of polymer-coated fertilizer, the permeabilities of N-, P-, and K-nutrient from saturated aqueous of urea, NaH₂PO₄ and KCl solution and the permeability of water vapor through the membranes of poly lactic acid (PLA), its blends with polystyrene (PS), and its composites with humic acid (HA) particles were determined experimentally at the temperatures of 288, 298, and 308 K, respectively. The effects of the addition of PS and HA particles, temperature, and coating thickness on the permeability of fertilizer nutrient and water vapor were investigated. It was found that the addition of PS and HA increased the permeability for both the fertilizer nutrients and water vapor. The increase in temperature raised the permeability of N-, P-, and K-nutrient while decrease the permeability of water vapor in the range studied.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Thermogelling water solutions of multifunctional macromonomers based on PLGA-PEG-PLGA triblock copolymers
Autorzy:: Michlovská, L.
Vojtová, L.
Mravcová, L.
Jančár, J.
Tematy:: biodegradable polymers
poly(ethylene glycol)
poly[(lactic acid)-co-(glycolic acid)]
sol-gel transition; Pokaż więcej
Wydawca:: Fundacja na Rzecz Młodych Naukowców
Powiązania:: https://bibliotekanauki.pl/articles/115692.pdf Link otwiera się w nowym oknie
Opis:: Biodegradable thermosensitive triblock copolymers based on poly(ethylene glycol) and poly[(lactic acid)-co-(glycolic acid)](PLGA-PEG-PLGA) with PLGA/PEG weight ratio in the range of 1.5–3.0 and LA/GA molar ratio equal to 2.4 or 3.0 were prepared via ring opening polymerization (ROP). Prepared copolymers were subsequently modified in “one pot” by itaconic anhydride (ITA) in order to functionalize both ends with carboxylic acid groups and reactive double bonds. Chemical structure was characterized by means of gel permeation chromatography and nuclear magnetic resonance. Aqueous solutions of both modified and unmodified copolymers are able to form free flowing sol at room temperature and clear gel at temperature around 37°C. Therefore, sol-gel transitions of PLGA-PEG-PLGA and ITA/PLGA-PEG-PLGA/ITA copolymers in aqueous solutions were investigated using test tube inverting method. No mater if copolymer is modified or not, it was found that the critical gel temperature (CGT) increased when the PLGA/PEG weight ratio dropped from 2.5 to 2.0 and that the critical gel concentration (CGC) grew up with decreasing molar ratio of LA/GA from 3.0 up to 2.4. However, in all cases the ITA functionalization improved sol-gel characteristics of original PLGA-PEG-PLGA copolymer by approaching gel phase to body temperature. As a result, aqueous solution of ITA/PLGA-PEG-PLGA/ITA having LA/GA = 3 and PLGA/PEG = 2 with concentration higher than 6 wt% might be suitable material for biomedical applications as injectable temporary implants.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Preparation of composite filaments and 3D prints based on PLA modified with carbon materials with the potential applications in tissue engineering
Autorzy:: Hunger, M.
Podgórny, W.
Frączek-Szczypta, A.
Tematy:: 3D printing
poly (lactic acid)
carbon materials
scaffold
tissue engineering; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Powiązania:: https://bibliotekanauki.pl/articles/285818.pdf Link otwiera się w nowym oknie
Opis:: This paper discusses the possibilities of obtaining polylactide-based composites and nanocomposites modified with carbon materials using the extrusion method, as well as the potential of their application in 3D printing technology. The aim of this research is to determine the impact of the presence of carbon additives on the properties of composites: mechanical, thermal and chemical. For this purpose, several research techniques were used such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), DSC/TG analysis, infrared Fourier-transform infrared spectroscopy (FTIR) and mechanical tests. It has been shown that it is possible to effectively produce composite materials based on PLA and carbon modifiers after optimization of the extrusion and printing process. Special attention should be paid to the quality of carbon phases homogenization in PLA matrix because the inappropriate dispersion may have a negative effect on the final properties of the composite, especially those modified with nanomaterials. Moreover, the reinforcing effect of carbon phases can be observed, and the quality of obtained filament with carbon fiber after recycling does not differ significantly from the quality of commercially available filaments. The obtained filament was successfully used to print three-dimensional scaffolds. Therefore, both the use of materials which are biodegradable and biocompatible with human tissue and the 3D printing method have the potential to be applied in tissue engineering.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Mechanical properties of 3d printed pla scaffolds for bone regeneration
Autorzy:: Kundreckaitė, Paula
Šešok, Andžela
Stonkus, Rimantas
Gaidulis, Gediminas
Romańczuk-Ruszuk, Eliza
Pauk, Jolanta
Tematy:: scaffold
bone regeneration
poly(lactic acid)
PLA
biodegradable polymers
mechanical properties
hyperelasticity; Pokaż więcej
Wydawca:: Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Powiązania:: https://bibliotekanauki.pl/articles/58907194.pdf Link otwiera się w nowym oknie
Opis:: The growing interest in biodegradable scaffolds for bone regeneration created a need to investigate new materials suitable for scaffold formation. Poly(lactic acid) (PLA) is a polymer commonly used in biomedical engineering, e.g. in tissue engineering as a biodegradable material. However, the mechanical behavior of PLA along its degradation time is still not explored well. For this reason, the mechanical properties of PLA scaffolds affected by incubation in physiological medium needs to be investigated to show the potential of PLA to be used as a material for biodegradable scaffold formation. The purpose of this research is to determine the mechanical properties of PLA scaffolds before and after incubation, and to apply constitutive material models for further behavior prediction. Two sets of PLA scaffolds were printed by the 3D printer “Prusa i3 MK3S” and sterilized by ultraviolet light and ethanol solution. The first set of specimens was incubated in DMEM (Dulbecco’s Modified Eagle Medium) for 60, 120, and 180 days maintaining 36.5 °C temperature. The mechanical properties of the scaffolds were determined after performing the compression test in the “Mecmesin MultiTest 2.5-i” testing stand with a force applied at two different speed modes. The obtained data was curve fitted with the hyperelastic material models for a model suitability study. The second set of specimens was incubated in PBS (Phosphate Buffered Saline) for 20 weeks and used in a polymer degradation study. The obtained results show that the mechanical properties of PLA scaffolds do not decrease during incubation in physiological medium for a predicted new bone tissue formation period, though hydrolysis starts at the very beginning and increases with time. PLA as a material seems to be suitable for the use in bone tissue engineering as it allows to form biocompatible and biodegradable scaffolds with high mechanical strength, required for effective tissue formation.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Analysis of the influence of electrospinning process parameters on the morphology of poly(lactic acid) fibres
Autorzy:: Matysiak, W.
Kapica, A
Tański, T.
Dubiel, A.
Tematy:: nanofibres
poly(lactic acid)
polylactide
PLA
electrospinning
nanowłókna
poli(kwas mlekowy)
polilaktyd
elektroprzędzenie; Pokaż więcej
Wydawca:: Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Powiązania:: https://bibliotekanauki.pl/articles/379142.pdf Link otwiera się w nowym oknie
Opis:: Purpose: The article focuses on the production of polymer nanofibres from poly(lactic acid) using the electro-spinning method, i.e. the technique of forming fibres in an electrostatic field. The main aim of the publication was to analyse the influence of the distance between electrodes on the morphology of one-dimensional polymeric materials obtained. Design/methodology/approach: In the practical part of the study solutions of polylactide in acetone and a mixture of chloroform/dimethylformamide (DMF) were produced. After 72 hours of mixing, no homogeneous solutions were obtained, therefore a solution consisting of a polylactide dissolved in chloroform was prepared, to which dimethylformamide was added in order to dilute the mixture. The morphology of the nanostructures obtained was analysed by means of a scanning electron microscope (SEM) equipped with an X-ray energy dispersion spectrometer (EDS), which allowed to analyse the chemical composition of the nanofibres produced. The electro-spinning method used to obtain fibres is characterized by high versatility - it gives the possibility to produce fibres from a wide range of polymers. Electro-spinning is also an economic method, and spinned fibres have a wide application potential. Findings: Nanofibres obtained by electro-spinning from the previously produced solution, regardless of the distance between the nozzle and the collector (10 or 20 cm) did not show any significant discrepancies in the values of measured diameters. Fibres obtained at increased distance between electrodes (20 cm) are characterized by a smaller average diameter value, but the difference is small, fluctuating between 48-49 nm. In the case of the sample formed during electro-spinning at the distance of the nozzle - collector equal to 10 cm and the sample produced at the distance doubled, no defects in the structure of the obtained nanofibres were observed. The analysis of topographic images of surfaces produced in the course of nanostructures' work did not show any significant influence of the distance between the nozzle and collector on the diameter of fibres. No defects in the structure of one-dimensional polymer materials obtained allowed to state that the distance between the nozzle and the collector in the range of 10-20 cm is the optimal parameter of the electro-spinning process allowing to obtain smooth, untangled fibres. Practical implications: The fibrous polymer mats obtained during the electro-spinning process of polylactide can be used as protective clothing materials, as drug delivery systems, as tissue scaffolding and as filtration membranes. Originality/value: At present, there are few articles in the literature on the electrospinning process, due to the fact that it is a constantly developing matte for the production of nanofibres. Moreover, most of the research focuses on fibres obtained from nonbiodegradable polymers, which do not have the advantages of fibres obtained from polylactide.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Impregnation of Poly(lactic Acid) with Polyphenols of Plant Origin
Impregnacja poli(kwasu mlekowego) (PLA) polifenolami pochodzenia roślinnego
Autorzy:: Latos-Brozio, Malgorzata
Masek, Anna
Tematy:: poly(lactic acid)
PLA
polyphenol
antioxidants
impregnation
poli(kwas mlekowy)
polifenol
przeciwutleniacze
impregnacja; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:: https://bibliotekanauki.pl/articles/234429.pdf Link otwiera się w nowym oknie
Opis:: The aim of the research was the solvent-based impregnation of poly(lactic acid) (PLA) with polyphenols of plant origin. The process is a scientific novelty because quercetin, rutin, xanthone and green tea extract had not been previously used to stabilise PLA as a result of the solvent-based impregnation of a polymer. As part of the work, the extruded poly(lactic acid) was impregnated with ethanol solutions of polyphenols. Samples after impregnation were subjected to tests: determination of mechanical properties, differential scanning calorimetry, melt flow index and SEM microscopy. In addition, the properties of the samples, such as the Vicat softening temperature and change in colour, before and after controlled weathering as well as thermal and UV aging were investigated. On the basis of the results presented, the effectiveness of the impregnation of poly(lactic acid) with natural compounds was confirmed as a new method of stabilisation of the biodegradable polyester selected.
Celem badań była rozpuszczalnikowa impregnacja poli(kwasu mlekowego) (PLA) z zastosowaniem polifenoli pochodzenia roślinnego. Proces jest nowością naukową, ponieważ kwercetyna, rutyna, ksanton i ekstrakt zielonej herbaty nie były wcześniej stosowane do stabilizacji PLA w procesie impregnacji polimeru. W ramach pracy wytłoczyny poli(kwasu mlekowego) impregnowano etanolowymi roztworami polifenoli. Próbki po impregnacji poddano badaniom: określeniu właściwości mechanicznych, różnicowej kalorymetrii skaningowej, wskaźnikowi szybkości płynięcia i mikroskopii SEM. Ponadto zbadano właściwości próbek, takie jak temperatura mięknienia Vicata i zmiana koloru, przed i po kontrolowanym starzeniu klimatycznym, termicznym i wywołanym promieniowaniem UV. Na podstawie przedstawionych wyników potwierdzono skuteczność impregnacji poli (kwasu mlekowego) związkami naturalnymi jako nową metodę stabilizacji wybranego biodegradowalnego poliestru.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Właściwości mechaniczne wyrobów wytworzonych technologią FDM
Mechanical properties of the elements produced by the FDM technique
Autorzy:: Tartakowski, Z.
Mydłowska, K.
Tematy:: szybkie prototypowanie
FDM
właściwości mechaniczne
PLA
rapid prototyping
mechanical properties
poly(lactic acid); Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Inżynierii Materiałów Polimerowych i Barwników
Powiązania:: https://bibliotekanauki.pl/articles/279073.pdf Link otwiera się w nowym oknie
Opis:: Modelowanie uplastycznionym tworzywem pozwala na wytworzenie elementów o skomplikowanej konstrukcji geometrycznej bez dodatkowego oprzyrządowania. Możliwość manipulowania wieloma parametrami procesu oraz kompozytowy charakter wytwarzanych części powoduje problemy z przewidzeniem ich właściwości. W niniejszej pracy przedstawiono badania wybranych właściwości mechanicznych wyrobów wytworzonych technologią FDM z PLA (poli(kwasu mlekowego)). Badano wpływ temperatury i prędkości druku oraz temperatury stołu drukującego na udarność, wytrzymałość na rozciąganie oraz twardość. Wyniki porównano z właściwościami próbek uzyskanych poprzez wtryskiwanie.
Fused deposition modeling allows to produce elements with complicated geometrical structure without any additional equipment. The ability to manipulate multiple parameters of the process and the composite nature of the manufactured parts causes problems with predicting their properties. In this paper the results of the research on PLA elements manufactured using FDM technique are presented. The effect of specific process parameters, namely: printing temperature, printing speed, and bed temperature on their mechanical properties such as impact strength, tensile strength, and toughness were investigated. Moreover, a comparison of mechanical properties with injected samples was conducted.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Comparison of Colour Properties of Polypropylene and Poly-(Lactic) Acid Fibres Dyed With Photoluminescent Dye
Autorzy:: Tomčíková, Zita
Panák, Ondrej
Hrabovská, Veronika
Ujhelyiová, Anna
Jančovičová, Viera
Wydawca:: Sciendo
Cytata wydawnicza:: Ujhelyiová, Anna, et al. "Comparison of Colour Properties of Polypropylene and Poly-(Lactic) Acid Fibres Dyed With Photoluminescent Dye" Fibres & Textiles in Eastern Europe, vol. 30, no. 5, Sciendo, 2022, pp. 17-27. https://doi.org/10.2478/ftee-2022-0040
Opis:: Every manufacturer wants to protect their textile products and their brand. A possible solution is, for example, the insertion of fibres with special pigments visible under irradiation by UV light into the final product. The paper focused on the study of the structure and colourimetric properties of polypropylene (PP) and poly-(lactic) acid (PLA) fibres modified with photoluminescent dye and halloysite (HNT) modified with photoluminescent dye. The photoluminescent dye and HNT modified with photoluminescent dye affected the structure of PP and PLA fibres differently. Increasing the HNT content up to 0.15 % increased the orientation of the PP fibres. In the case of PLA fibres, the increased content of photoluminescent dye in PLA fibres increased their orientation in the observed concentration area. PLA-based knitted fabrics showed better light stability, where there was no visible degradation of the knitted fabric, only its darkening. Likewise, PLA-based knitted fabric showed luminescence in UV light even after accelerated light aging.
This work was supported by the Slovak Research and Development Agency under contract No: APVV-17-0078 and APVV-21-0172.
Dostawca treści:: Repozytorium Centrum Otwartej Nauki

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Skocz do pozycji: 10.

Tytuł:: Innowacyjne kompozyty poli(kwasu mlekowego) do produkcji folii opakowaniowych
Innovative composites of poly(lactic acid) for the production of packaging foils
Autorzy:: Vuković-Kwiatkowska, I.
Kaczmarek, H.
Dzwonkowski, J.
Tematy:: poli(kwas mlekowy)
poliakrylany
fotosieciowanie
folie opakowaniowe
poly(lactic acid)
polyacrylates
photocrosslinking
packaging films; Pokaż więcej
Wydawca:: Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Powiązania:: https://bibliotekanauki.pl/articles/141987.pdf Link otwiera się w nowym oknie
Opis:: Otrzymano i zbadano podstawowe właściwości innowacyjnych kompozytów do produkcji folii opakowaniowych. Kompozyty otrzymano metodą fotochemiczną z poli(kwasu mlekowego) (PLA) i poliakrylanu o różnym składzie. Zbadano właściwości mechaniczne otrzymanych folii; przenikalność przez folie pary wodnej i ditlenku węgla; odporność folii na działanie promieniowania nadfioletowego, stosowanego w procesie sterylizacji oraz określono wpływ wymrażania w temp. -18°C na badane właściwości. Stwierdzono poprawę właściwości barierowych i mechanicznych otrzymanych kompozytów w stosunku do czystego PLA, ich dobrą stabilność fotochemiczną i odporność na niskie temperatury, co stwarza możliwość wykorzystania nowych innowacyjnych kompozytów do produkcji opakowań żywności.
Innovative composite packaging films were obtained from poly (lactic acid) (PLA) and polyacrylate. Mechanical properties, permeability to water vapor and carbon dioxide through the composite films, as well as their resistance to ultraviolet radiation used in the sterilization process were studied. The influence of refrigeration -18°C on the properties was tested. An improvement in barrier and mechanical properties of the composites with respect to the pure PLA was found, as well as their good photochemical stability and resistance to low temperatures, which makes it possible to use these composites in the food packaging production.
Dostawca treści:: Biblioteka Nauki

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