Effect of partial replacement of chitosan with halloysite nanotubes on the properties of polylactic acid hybrid biocomposites

Abstract

In this study, hybrid chitosan/halloysite nanotubes (Cs/HNTs) reinforced polylactic acid (PLA) were prepared via melt compounding and compression molding techniques. In the fabrication of PLA/Cs/HNTs hybrid biocomposites, the partial replacement of Cs with HNTs was performed at filler loading of 2.5 parts per hundred parts of polymer (php), proceeding from the highest tensile strength of PLA/Cs obtained in our previous study. Cs was partially replaced with different HNTs loadings (0.5, 1, 1.5, 2, and 2.5) php and its effects on the functional group, thermal, tensile, morphological, and water absorption properties were investigated systematically. The results revealed that the combined loading of 1 php Cs and 1.5 php HNTs hybrid fillers into PLA showed the best performance in all properties. Fourier transform infrared spectroscopy (FTIR) analysis indicated that the siloxane (SiO) group of HNTs had chemically interacted with the amine group of Cs. The thermal analysis demonstrated that partial replacement of Cs with 1.5 php HNTs improved the thermal stability of PLA/2.5Cs/0HNTs biocomposite by ~12%. Yet, the percentage of crystallinity (χc) reduced with HNTs addition due to the phase adhesion improvement. Moreover, PLA/1Cs/1.5HNTs hybrid biocomposites showed the highest tensile strength and elongation at break of 59 MPa and 2.72%, respectively. This correlated with the uniform dispersion and better interfacial adhesion between Cs/HNTs fillers in the PLA matrix, as confirmed by the field emission scanning electron microscopy (FESEM). In addition, partial replacement of Cs with HNTs exhibited a lower water absorption percentage, which suggested the advantage of hybrid fillers to reduce water uptake, and is beneficial in a wide range of applications.

Properties enhancement of chitosan‐filled polylactic acid biocomposites using tannic acid treatment

“…Additionally, the major degradation step was presented at 200-380 C, which represented approximately ~93%-98% of weight losses. This was ascribed by the simultaneous degradation of PLA molecules and the breakdown of saccharide structure of Cs component as stated in the study reported by Kamaludin et al 57 The degradation of carbonaceous residue occurred beyond 400 C.…”

Fabrication and Application of Halloysite Nanotube-Embedded Photocatalytic Nanofibers with Antibacterial Properties

“…Bare and composite nanofibers showed C–O stretching vibration at 1375 cm –1 . , The peak at 1666 cm –1 was related to the −CC– bonds in the PAN structure. The stretching vibration of O–H on the inner surface of the HNT is related with the distinctive bands in the FTIR spectra of HNT at 3625 cm –1 . , The strong vibration band seen at 1000–1038 cm –1 can be attributed to the Si–O–Si bond originating from the HNT . Vibration bands seen at this wavenumber are not examined in the bare membrane but are measured in bare HNT powder and all of HNT composite nanofilters.…”