Preparation and characterization of PLA composites with modified magnesium hydroxide obtained from seawater

Abstract

Modification of poly(lactic acid) (PLA) was performed with the surface modified magnesium hydroxide (mMH) obtained from seawater. Surface modification of MH with different amount of stearic acid (SA) results in chemically bonded SA, stearate as confirmed by Fourier transform infrared spectroscopy (FT-IR). Based on FT-IR and X-ray diffraction (XRD) analysis modified filler with a higher amount of SA was used for the composite preparation. PLA/m10MH composites were prepared using laboratory mixing extruder. Differential scanning calorimetry (DSC) was applied to study thermal properties and crystallinity of PLA/mMH composites, while the thermal stability was performed by thermogravimetric analysis (TG). According to DSC analysis, PLA crystallization is primary influenced by the filler. PLA/m10MH composites degrade in four degradation stages. With an increase of m10MH content in the composites, their thermal degradation becomes more complex and their thermal stability is getting worse. XRD and X-ray microcomputed tomography (XμCT), used to obtain structural and microstructural information about PLA/m10MH composites, revealed that addition of m10MH decreases the crystallinity of PLA, increases the porosity of the composite and produces agglomeration of mMH.

Hydrolytic Degradation and Bioactivity of Electrospun PCL-Mg-NPs Fibrous Mats

“…The peak at around 3675 cm −1 that is observed at T0 and T7 and disappears at a higher immersion time is related to the -OH stretching vibration of Mg NPs, indicating the presence of hydroxyl group on the surface of low-coordination sites [ 36 ]. Furthermore, it is possible to observe the peak associated to the physically adsorbed water molecules at 3450 cm −1 [ 37 ]. Additional peaks at approximately 2950 (asymmetric) and 2864 cm −1 (symmetric) are related to the stretching CH 2 bond, while the signal at 1460 cm −1 corresponds to the CH 2 bending vibration [ 38 ].…”

Degradable MXene-Doped Polylactic Acid Textiles for Wearable Biomonitoring

“…To explore the chemical composition and surficial bondings, FTIR characterizations of pristine PLA textiles and the DMPT before and after degradation were performed as displayed in Figure c,d, respectively. Like other carbonyl compounds, esters are primarily recognized by the stretching vibration peak of the −CO group at 1749 cm –1 and the vibration peaks of the −COC– group at 1181 and 1083 cm –1 , as shown in Figure c. The absorbing intensity ratio of the −COC– group to the −CO group was decreased after degradation, suggesting that some ester bonds are broken and PLA with a lower degree of polymerization is formed and attached to the pristine PLA textiles, resulting in the decrease of the −COC– group, and the −CO group remains unchanged .…”

4D Printed Poly(l‐lactide)/(FeCl3–TA/MgO) Composite Scaffolds with Near‐Infrared Light‐Induced Shape‐Memory Effect and Antibacterial Properties

“…This observation indicates the successful incorporation of TA-Fe 3þ into the MgO structure. [26] The complete XPS spectrum of the FeCl 3 -TA/MgO composite particle is presented in Figure 3b. Although the 2p peak for Fe is detected, it appears insignificant, which is possibly due to its low Fe 3þ content.…”