Abstract:The effect of hydroxyapatite (HAp) synthesized by the chemical precipitation process on the morphology and properties of composites based on poly(lactic acid) (PLA) was investigated at various filler content ratios, i.e., 5, 10 and 15 wt%. Both neat PLA and PLA-based composites were first prepared using the solvent casting method, followed by melt compounding in an internal mixer, whereas tensile specimens were obtained by thermo-compression. The study revealed that the addition of 5 wt% of HAp into the PLA le… Show more
“…In more detail, HAp increases the polymer activation energy and initial decomposition temperature, but once the degradation process is initiated, the degradation rate is higher. Recently, Tazibt et al [ 32 ] reported that fine dispersion of HAp can increase the degradation temperature in PLA composite, while higher filler content with nonideal dispersion can have the opposite effect on the properties. Compared with the neat PLA, the thermal degradation curves of our composite samples are shifted to higher temperatures, which could indicate a good dispersion of HAp in the matrix.…”
Production of biocompatible composite scaffolds shifts towards additive manufacturing where thermoplastic biodegradable polymers such as poly(lactic acid) (PLA) are used as matrices. Differences between industrial- and medical-grade polymers are often overlooked although they may affect properties and degradation behaviour as significantly as the filler addition. In the present research, composite films based on medical-grade PLA and biogenic hydroxyapatite (HAp) with 0, 10, and 20 wt.% of HAp were prepared by solvent casting technique. The degradation of composites incubated in phosphate-buffered saline solution (PBS) at 37 °C after 10 weeks showed that the higher HAp content slowed down the hydrolytic PLA degradation and improved its thermal stability. Morphological nonuniformity after degradation was indicated by the different glass transition temperatures (Tg) throughout the film. The Tg of the inner part of the sample decreased significantly faster compared with the outer part. The decrease was observed prior to the weight loss of composite samples.
“…In more detail, HAp increases the polymer activation energy and initial decomposition temperature, but once the degradation process is initiated, the degradation rate is higher. Recently, Tazibt et al [ 32 ] reported that fine dispersion of HAp can increase the degradation temperature in PLA composite, while higher filler content with nonideal dispersion can have the opposite effect on the properties. Compared with the neat PLA, the thermal degradation curves of our composite samples are shifted to higher temperatures, which could indicate a good dispersion of HAp in the matrix.…”
Production of biocompatible composite scaffolds shifts towards additive manufacturing where thermoplastic biodegradable polymers such as poly(lactic acid) (PLA) are used as matrices. Differences between industrial- and medical-grade polymers are often overlooked although they may affect properties and degradation behaviour as significantly as the filler addition. In the present research, composite films based on medical-grade PLA and biogenic hydroxyapatite (HAp) with 0, 10, and 20 wt.% of HAp were prepared by solvent casting technique. The degradation of composites incubated in phosphate-buffered saline solution (PBS) at 37 °C after 10 weeks showed that the higher HAp content slowed down the hydrolytic PLA degradation and improved its thermal stability. Morphological nonuniformity after degradation was indicated by the different glass transition temperatures (Tg) throughout the film. The Tg of the inner part of the sample decreased significantly faster compared with the outer part. The decrease was observed prior to the weight loss of composite samples.
“…The diffraction peaks in the composite samples showed that HAP was present in the polymer matrix at filler loading 1, 3, 5 and 10 wt%. 32,33 Figure 3.WAXD graph of PLA, HAP and its composites.…”
Section: Resultsmentioning
confidence: 99%
“…Indeed both PLA and HAP are rigid and brittle material. 33 From the stress strain graph of PLA and PLA composites it can be observed that the composite sample tend to reach the yield stress, drawing through its neck (plastic deformation, where the sample extends elastically) and reaches the lower yield point, after which it draws until break. Necking of the composites samples is followed by a plateau region that extends until the breaking point due to the strain induced crystallization of the polymer resulting in the material hardening.…”
Section: Resultsmentioning
confidence: 99%
“…It can be considered that HAP particles agglomerates more at higher wt% of filler loading i.e., 5 and 10 wt% rather than 1 and 3 wt%. 33 For higher wt% of filler loading HAP aggregates into clusters of different sizes as seen in PLA matrix. Since aggregates can act as a point for stress concentration that can cause the premature failure of the PLA/ HAP composites.…”
In this study, biocomposites as feedstock material for 3D printing were produced by poly (lactic acid) (PLA) as a polymer matrix and Hydroxyapatite (HAP) as reinforcing filler for potential use in biomedical applications. Biocomposites filament from PLA and different HAP content varying from 1–10 wt% were prepared from extrusion and then injection moulding process. The impact of HAP loading on the properties of biocomposites was investigated for crystallinity, density, hardness, tensile, impact, flexural, melt flow index (MFI), thermal properties and biomineralization studies. The formation of PLA/HAP biocomposites was confirmed by fourier transform infrared spectroscopy (FTIR). The hydrophilicity of the biocomposites was studied by contact angle analysis. Dispersion of HAP into PLA matrix was confirmed by scanning electron microscopy (SEM) and optical microscopy. The HAP addition increased the density of the composites. From mechanical analysis PLA/HAP composites containing 1–5 wt% showed an increase in tensile modulus. The Shore D hardness of the composites increased with increase in wt% of HAP content. The maximum hardness was achieved for 10 wt% of HAP content i.e., 87 ± 0.1, which is about 6.1% more than neat PLA. The MFI increased with rise in HAP content that gives a positive opinion of reinforcing PLA composites without deteriorating the processability. The hydrophilicity of the biocomposites was slightly increased after the addition of HAP. From thermal analysis it was concluded that the thermal stability of the biocomposites increased when compared with neat PLA. From the Biomineralization studies formation of apatite layer on PLA composites was confirmed by SEM analysis.
“…Leones et al [16] studied PLA's thermal and mechanical properties and shape memory behavior reinforced with magnesium oxide (MgO) NPs. Tazibt et al [17] evaluated the effect of hydroxyapatite (HA) on the morphological and physical properties of PLA-HA composites. Among inorganic NPs, zinc oxide (ZnO) has gained interest in the last years since it is recognized as bio-safe material.…”
In this work, electrospun nanofibers based on polylactic acid, PLA, reinforced with ZnO nanoparticles have been studied, considering the growing importance of electrospun mats based on biopolymers for their applications in different fields. Specifically, electrospun nanofibers based on PLA have been prepared by adding ZnO nanoparticles at different concentrations, such as 0.5, 1, 3, 5, 10 and 20 wt%, with respect to the polymer matrix. The materials have been characterized in terms of their morphological, mechanical, and thermal properties, finding 3 wt% as the best concentration to produce PLA nanofibers reinforced with ZnO nanoparticles. In addition, hydrolytic degradation in phosphate buffer solution (PBS) was carried out to study the effect of ZnO nanoparticles on the degradation behavior of PLA-based electrospun nanofiber mats, obtaining an acceleration in the degradation of the PLA electrospun mat.
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