Naslov
Thermal properties of polylactic acid/modified magnesium hydroxide composites

Autori
Perinović Jozić, Sanja ; Gregurić, Antonija ; Jakić, Jelena ; Andričić, Branka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of abstracts of the 5 th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC5) and 14 th Mediterranean Conference on Calorimetry and Thermal Analysis (Medicta2019) / Andrei, Rotaru ; Stefano, Vecchio Ciprioti - Lahti, 2019, 210-210

ISBN
978-3-940237-59-0

Skup
5th Central and Eastern European Conference on Thermal Analysis and Calorimetry (CEEC-TAC5) ; 14th Mediterranean Conference on Calorimetry and Thermal Analysis (Medicta2019)

Mjesto i datum
Rim, Italija, 27.08.2019. - 30.08.2019

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
stearic acid ; surface modification ; PLA/modified Mg(OH)2 composites ; thermal properties ; thermal stability

Sažetak
Polylactic acid (PLA) has become interesting for research because of its possible use in various application fields due to its biodegradability. PLA belongs to the polymers derived from the renewable resources such as sugar cane corn. The application of this polymer, as well as other polymers, is often limited by their flammability. This problem can be solved by adding flame retardants. Flame retardants should prevent the start of the combustion reaction or quickly stop the reaction if it has already begun. Magnesium hydroxide (Mg(OH)2) is an environmentally friendly metal hydroxide that is increasingly used as a functional inorganic filler and in this case as a flame retardant for PLA. Mg(OH)2 is possible to produce by extraction from ores, such as magnesite, dolomite, or serpentinite, and from brine/seawater [1]. Inorganic fillers are often surface modified for better interaction with a polymer, i.e. better adhesion, and hence better polymer properties. The aim of this study was to prepare PLA/modified Mg(OH)2 composites of the satisfactory thermal properties and the thermal stability to extend the PLA application field. Mg(OH)2 was obtained from seawater as an unlimited source of this material. Modification of Mg(OH)2 was performed with 5 and 10% of stearic acid relative to the hydroxide. Using infrared spectroscopy with Fourier transformation (FT-IR) successful chemisorption of stearic acid on the filler surface was confirmed, after which two series of PLA/modified Mg(OH)2 composites were prepared using a laboratory single-screw extruder. The amount of the modified Mg(OH)2 was up to 20 wt %. Differential scanning calorimetry (DSC) was used to investigate the effect of the modified filler on the thermal properties of PLA. Addition of the modified inorganic filler has a complex effect on the PLA thermal properties, with a clear reduction in PLA crystallinity for both composite series. Thus, modified Mg(OH)2 doesn’t act as a nucleation agent in the PLA composites. The amount of stearic acid doesn’t make noticeable influence on the thermal characteristics of PLA. The thermal stability of the composites was investigated using thermogravimetry (TG). PLA degrades in one degradation stage and the both modified Mg(OH)2 in two. The both PLA/modified Mg(OH)2 composite series degrades up to four degradation stages. With the increase of the modified Mg(OH)2 content in both composite series their decomposition becomes the more complex and the thermal stability of PLA is getting worse. Different amounts of stearic acid used for filler modification didn’t produce any influence on the thermal stability of PLA.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

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