Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 2020

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Polycarbonate

Sortuj według:

Ogranicz wyniki do:

Influence of 3D-printing on the flammability properties of railway applications using polycarbonate (PC) and polylactic acid (PLA)

Hohenwarter Dieter, Fischer Christopher, Berger Matthias

Problemy Kolejnictwa

2020

Z. 187

99--107

Due to limited production numbers, using additive manufacturing for the production of railway components, is proving more economical. Furthermore, strict requirements regarding flammability properties, standardised in EN 45545-2, are applied on trains. This work focuses on the production of transparent components made of Polycarbonate via 3D-printing. The polymer was modified using different flame retardant agents and the influence of the printing parameters, especially the print density, was determined. Polylactic Acid was examined for comparison reasons only. The printed and modified polymers were tested exposing the samples to heat radiation, according to ISO 5660-1 using a Cone Calorimeter, and to a direct flame, according to UL 94. Processing and printing of the polymer causes thermal stress to the molecules. This may lead to a worsening of the flammability causing a decline of the properties compared to the native Polycarbonate. This was confirmed through both testing methods. Moreover, the additive and the print density both influence the flammability properties depending on the polymer type. In summary print parameters and additivation have to be carefully considered when it comes to the flammability properties of polymers.

Polycarbonate biodegradation by newly isolated Bacillus strains

Arefian Mojgan, Tahmourespour Arezoo, Zia Mohammadali

Archives of Environmental Protection

2020

Vol. 46, no. 1

14--20

As polycarbonate is frequently used in many products, its accumulation in landfills is absolutely harmful to the environment. The aims of this study were the screening and isolation of polycarbonate-degrading bacteria (PDB) and the assessment of their ability in the degradation of polycarbonate (PC) polymers. Nine-month buried- -PC films were used for PDB isolation and identification. The biodegradation ability of the isolates was determined by growth curve, clear zone formation, lipase and amylase production, AFM and FTIR. Bacillus cereus and Bacillus megaterium were identified and considered as PDB. The degradation ability of B. megaterium was significantly higher than that of B. cereus. Both were lipase and amylase positive. AFM and FTIR results showed the initiation of bacterial attachment. The PC biodegradation ability of isolates can be very efficient. Finding such efficient isolates (which was less studied before) will promise a decrease in plastic contamination in the future.