This study presents the physicochemical and mechanical behavior of incorporating hydroxyapatite (HAp) with polylactic acid (PLA) matrix in 3D printed PLA/HAp composite materials. Effects of powder loading to the composition, crystallinity, morphology, and mechanical properties were observed. HAp was synthesized from locally sourced nanoprecipitated calcium carbonate and served as the filler for the PLA matrix. The 0, 5, 10, and 15 wt. % HAp biocomposite filaments were formed using a twin-screw extruder. The resulting filaments were 3D printed in an Ultimaker S5 machine utilizing a fused deposition modeling technology. Successful incorporation of HAp and PLA was observed using infrared spectroscopy and X-ray diffraction (XRD). The mechanical properties of pure PLA had improved on the incorporation of 15% HAp; from 32.7 to 47.3 MPa in terms of tensile strength; and 2.3 to 3.5 GPa for stiffness. Moreover, the preliminary in vitro bioactivity test of the 3D printed PLA/HAp biocomposite samples in simulated body fluid (SBF) indicated varying weight gains and the presence of apatite species’ XRD peaks. The HAp particles embedded in the PLA matrix acted as nucleation sites for the deposition of salts and apatite species from the SBF solution

Utilization of natural biopolymers has shown potential in generating innovations for tissue engineering applications. This study aims to fabricate scaffolds from cellulose acetate derived from kapok fiber. Cellulose is extracted from raw kapok fibers by alkali treatment and delignification then synthesized into cellulose acetate. Kapok cellulose acetate (KCA) is dissolved in dimethyl sulfoxide to fabricate the scaffold. Materials were characterized using Attenuated Total Reflectance – Fourier Transform Infrared (ATR-FTIR) spectrometer, X-ray diffractometer (XRD) and Differential Scanning Calorimeter (DSC). FTIR analysis has shown that cellulose was extracted from kapok and cellulose acetate was successfully synthesized. XRD analysis also confirmed the presence of cellulose acetate. Results have also shown that synthesized KCA seems to have higher crystallinity than commercially available cellulose acetate (CCA). The degree of substitution (DS) of KCA was found to be 2.85 which is close to the DS value of tri-substituted cellulose acetate. DSC analysis has shown lower glass transition temperature of 52.15°C but higher degradation temperature of 300.43°C than the CCA. Moreover, the values for the enthalpy of fusion for two endotherms of KCA (44.0556 J/g and 18.6946 J/g) are higher than the values for CCA by 344% and 261%, respectively; thus, indicating the higher degree of crystallinity for synthesized KCA samples.

This research involved the development of membranes with local raw materials to suit water and wastewater treatment applications. Indigenous montmorillonite clay was surface modified with dialkyldimethyl ammonium chloride to be used as functional additive in polymeric membranes. Polysulfone (PSf) pellets were dissolved in N-methyl-pyrrolidone (NMP) and organomodified-montmorillonite (OMMT) or nanoclay was incorporated at varying concentrations up to 1.00%. Casting solutions were vacuum-mixed and degassed using a planetary mixer then casted using MEMCAST™ to produce flat sheet membranes. Characterizations include X-Ray Diffractometry, Atomic Force Microscopy, Scanning Electron Microscopy, and contact angle measurement. The exfoliation of OMMT platelet structures within the PSf matrix at 1.00% loading showed improved surface roughness and more porous morphology. Improved surface roughness was observed with an increasing value as a function of increasing OMMT concentration. Meanwhile, the morphology of the nanocomposite membranes showed three distinct layers: dense skin layer, porous finger-like layer, and sponge-like structured layer. Moreover, the contact angle of the membranes decreased by 13.7% with 1.00% addition. This enhancement in hydrophilicity could affect properties like permeate flux and membrane fouling, which could play an important role in the functional performance of synthesized membranes with nanoclay additives. One-way ANOVA revealed that the change in OMMT concentration has significant effect on the surface roughness and contact angles of the membranes at 95% confidence level.

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