Catalytic Degradation of Polylactic Acid over Al2O3@SiO2 Core-Shell Catalysts
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Tarih
2021
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Al2O3@SiO2 core-shell catalysts were synthesized by sol-gel method. The core size'control was provided by using of polyethylene glycol (PEG) and glycerol. The shell thickness was optimized by using the different amount of tetraethylorthosilicate (TEOS). The formation of core and shell structures in catalysts was seen in high resolution transmission electron microscopy (HRTEM) images. In some catalysts, the use of PEG caused to formation of a more monodisperse core structure. The particle size of catalysts was observed in the range of 8-12 nm. The BET (Brunauer-Emmett-Teller) surface area and total pore volume of catalysts ranged 440-1014 m(2)/g and 1.28-2.57 cm(3)/g, respectively. In addition, pore diameter reached up to 25 nm. The use of PEG and glycerol improved textural properties. While BET surface area and total pore volume values decreased by the increase of TEOS amount, shell thickness increased a little. Fourier transform infrared (FTIR) spectrums of the pyridine adsorbed catalysts revealed the presence of Lewis and Bronsted acid sites in the catalysts. The catalysts were tested in the degradation of polylactic acid (PLA) by using thermogravimetric analysis (TGA) technique. TGA results showed the degradation temperature of PLA decreased from 353 to 321 degrees C in the presence of catalysts. Activation energy values were calculated using Flynn-Wall-Ozawa method. The activation energy was reduced from 337 to 199 kJ/mol. Pore structure, particle size and acidity of catalysts significantly affected the degradation performance.
Açıklama
Anahtar Kelimeler
Al2O3@SiO2, Core-shell catalyst, Size control agent, Polylactic acid, Degradation
Kaynak
Journal Of Polymers And The Environment
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
29
Sayı
7
