Wyniki wyszukiwania - BazTech

1

Effect of Tin Addition on the Degradability and Corrosion Properties of a New Zn-1.0 wt.% Mg Alloy

Long Zhouling, Lang Haiyang, Ou Jun

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 4

1209--1216

EN

In this study, to investigate effects of tin addition on the microstructures and corrosion properties, Zn-1Mg-xSn (x = 1.0, 2.0 and 5.0 wt.%) ternary zinc alloys were prepared. The experimental results indicated that the Zn-1Mg-2.0 wt.% Sn alloy has the better mechanical properties compared with pure zinc and Zn-1Mg alloy. The tensile strength of the alloy material is 173.2±3.7 MPa, the yield strength is 120.7±2.4 MPa, the elongation is 5.64±0.08% and the hardness is 76.9±0.8 HV. The average degradation rate of the alloys immersion in SBF solution for 60 days is 0.16±0.03 mm/year, and the Zn-1Mg-2.0 wt.% Sn alloy hemolysis rate is only 0.81±0.02%. It is confirmed that the addition of tin is effective to improve the mechanical properties and degradation of Zn-1Mg alloy. It may be a candidate of the clinical application requirements of the degradable implant materials in orthopedics.

2

Physicochemical Assessment of the Biodegradability of Agricultural Nonwovens Made of PLA

Miros-Kudra Partycja, Gzyra-Jagieła Karolina, Kudra Michał

Fibres & Textiles in Eastern Europe

|

2021

|

Vol. 29, no. 1 (145)

26--34

EN

Compostable biodegradable plastics are an ecological alternative to traditional products based on petroleum derivatives, whose post-use waste may pollute the natural environment. Modern polymer materials show the functional properties of plastics obtained by conventional methods, but they also may be degraded as a result of biochemical transformations in composting. This allows such materials to be included in the scheme of the currently implemented circular economy, which does not generate post-consumer waste. This paper presents methods for the assessment of the biodegradation process of selected agricultural nonwovens produced from commercial PLA 6252D polylactide, supplied by Nature Works® LLC, USA. The agricultural nonwovens tested, obtained by the spun-bond technique, were characterised by different degrees of crystallinity in the range from 11.1% to 31.4%. Biodegradation tests were carried out as simulated aerobic composting while maintaining constant environmental conditions in accordance with test procedures based on PN-EN/ISO standards using the method of sample mass loss determination. Gel chromatography (GPC/SEC) and FTIR spectroscopy were also applied to assess the degree of biodegradation. The aim of this study was to evaluate the effect of the crystallinity of nonwoven made of PLA 6252 D on its degradation in a compost environment.

PL

Kompostowalne tworzywa biodegradowalne są ekologiczną alternatywą dla tradycyjnych produktów opartych na pochodnych ropy naftowej, zalegających i zanieczyszczających środowisko naturalne w formie odpadów poużytkowych. Nowoczesne materiały polimerowe wykazują właściwości użytkowe tworzyw sztucznych otrzymywanych metodami konwencjonalnymi a ponadto ulegają utylizacji na drodze przemian biochemicznych w wyniku kompostowania. Pozwala to na wpisanie się takich materiałów w schemat obecnie pożądanej gospodarki cyrkularnej, która nie generuje odpadów poużytkowych. W niniejszej pracy przedstawiono metody badań biorozkładu wybranych agrowłóknin wytworzonych z komercyjnego polilaktydu PLA 6252D firmy Nature Works® LLC, USA. Badane agrowłókniny otrzymane techniką spun-bonded charakteryzowały się różnymi stopniami krystaliczności w zakresie od 11.1% do 31.4%. Badania biodegradacyjnie prowadzono w procesie symulowanego kompostowania aerobowego z zachowaniem stałych warunków środowiskowych zgodnie z procedurami badawczymi na podstawie norm PN-EN/ISO z wykorzystaniem metody wyznaczania ubytku masy. Do oceny stopnia biodegradacji zastosowano również technikę chromatografii żelowej (GPC/SEC) oraz spektrofotometrię FTIR. Celem pracy było określenie wpływu krystaliczności włóknin wytworzonych z PLA 6252 D na rozkład w środowisku kompostowym.

3

Chemical oxidation of polycyclic aromatic hydrocarbons in water by ferrates(VI)

Antošová Barbora, Hrabák Pavel, Antoš Vojtěch, Wacławek Stanisław

Ecological Chemistry and Engineering. S

|

2020

|

Vol. 27, nr 4

529--542

EN

Polycyclic aromatic hydrocarbons (PAHs) are a common part of the environment where they come from burning fossil fuels (through an incomplete combustion process). From a toxicological point of view, PAHs are considered to be carcinogens with a mutagenic and teratogenic effect. On the other hand, ferrates are generally believed to be the ideal chemical agent for water treatment due to their strong oxidation potential. Herein, the efficiency of degradation of PAHs (with the special emphasis on B[a]P) by ferrates under laboratory conditions was studied. The formation of degradation products was also considered. For this, two types of ferrates were used and both of them efficiently degraded B[a]P. When comparing ferrates that were bought from a Czech and USA company, no significant changes in terms of B[a]P degradability were observed. It was determined that the degradation efficiency of PAHs by ferrates was dependent on their molecular weight. Two and three cyclic PAHs have been completely degraded within 30 minutes, whereas five (and more) cyclic PAHs, only partially. The results obtained with ferrates were compared to the ones obtained with a classical oxidizing agent - KMnO4. In a qualitative test to detect degradation products of PAHs, two were identified, namely fluoren-9-one derived from fluorene and acentaphthylene, formed from acenaphthene.

4

Different behaviour of adipose tissue-derived stem cells and vascular smooth muscle cells on modified poly(L-lactic acid) foils

Travnickova Martina, Sedlar Antonin, Musilkova Jana, Slepickova Kasalkova Nikola, Slepicka Peter, Svorcik Vaclav, Bacakova Lucie

Engineering of Biomaterials

|

2019

|

Vol. 22, no. 153 spec. iss.

72

5

How do degradable/biodegradable plastic materials decompose in home composting environment?

Vaverková M., Adamcová D., Zloch J

Journal of Ecological Engineering

|

2014

|

Vol. 15, nr 4

82--89

EN

This paper provides information about biodegradability of polymeric (biodegradable/ degradable) materials advertised as 100%-degradable or certified as compostable, which may be a part of biodegradable waste, in home composting conditions. It de-scribes an experiment that took place in home wooden compost bins and contained 9 samples that are commonly available in retail chains in the Czech Republic and Poland. The experiment lasted for the period of 12 weeks. Based on the results thereof it can be concluded that polyethylene samples with additive (samples 2, 4, 7) have not decomposed, their color has not changed and that no degradation or physical changes have occurred. Samples 1, 3 and 5 certified as compostable have not decomposed. Sample 6 exhibited the highest decomposition rate. Samples 8, 9 (tableware) exhib-ited high degree of decomposition. The main conclusion from this study is that degradable/ biodegradable plastics or plastics certified as compostable are not suitable for home composting.

6

Degradowalne poli(estrouretany) z cykloalifatycznego diizocyjanianu i kopoliestrodioli z L-laktydu i poli (epsilon-kaprolaktono) diolu

Masiulanis B., Radomska A., Żegliński J.

Elastomery

|

2003

|

T. 7, nr 4

3-9

PL

Opisano syntezę liniowych poli(estrouretanów) (PESU) z 4,4`-diizocyjanianu dicykloheksylenometanu, 1,4 - butanodiolu i kopoliestrodioli z L-laktydu (LA) i poli(e-kaprolaktono)diolu (PCL, Mn 560 g/mol). Kopoliestrodiole o Mn 760, 1250 i 3390 g/mol otrzymano przy trzech stosunkach masowych PLA i PCL w obecności oktanianu Sn (II). PESU otrzymane przy różnych stosunkach molowych komponentów scharakteryzowano przez pomiary twardości, wytrzymałości na rozciąganie i badania degradowalności w buforze fosforanowym o pH = 7,4, w temp. 38 0C. Oznaczono kąty zwilżania wodą, chłonność wody i chłonność oleju roślinnego. Właściwości termiczne PESU określono z użyciem dynamiczno-mechanicznej analizy termicznej (DMTA) i analizy termograwimetrycznej (TGA). Podatność otrzymanych PESU na degradację hydrolityczną porównano z degradowalnością opisanych w literaturze usieciowanych poli(estrouretanów) opartych na kopoliestrotriolach z LA i epsilon-kaprolaktonu.

EN

Synthesis of the linear poly(esterurethanes) (PESUs) from the cycloaliphatic diisocyanate, 1,4-butane diol and copolyesterdiols from L-lactide (LA) and poly(e-caprolactone) diol (PCL, Mn 560 g/mol) have been described. The copolyester diols of Mn 760, 1250 and 3390 g/mol were prepared with three mass proportion of LA and PCL in the presence of Sn (II) octoate. PESUs obtained with different molar ratio of the components were characterized by hardness, tensile-stress properties and degradability in the phosphate buffer solution of pH = 7,4 at temp. 38 0C. The contact angles with water, sorption of water and vegetable oil were denoted. Thermal properties of PESUs were investigated by dynamic mechanical thermal analysis (DMTA) and by thermogravimetric analysis (TGA). The fitness of PESUs on hydrolytical degradability has been compared with degradability of known crosslinked poly(esterurethanes) from copolyester triols based on LA and epsilon-caprolactone.