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Different blends of poly(lactic acid) (PLA) and polybutylene succinate (PBS), and their harakeke fiber‐reinforced composites were studied. Scanning electron microscopy showed that the PLA and PBS are incompatible and poorly miscible. Tensile strength and tensile modulus of the blends were found to reduce as the amount of PBS increased. Reinforcement alone was not able to significantly improve the mechanical performance of the blend, which is lower than that of neat PLA. Therefore, simultaneous reinforcement and reactive compatibilization were performed using harakeke fiber, and dicumyl peroxide as reinforcement and compatibilizer, respectively. This produced about 201% increase in the crystallinity of PLA. Compared with the PLA/PBS blend, the dual effect approach increased the tensile strength and tensile modulus by 31% and 148%, respectively. Likewise, dynamic mechanical analysis showed that the thermomechanical properties of the composite greatly improved. [ABSTRACT FROM AUTHOR]

Mechanical processing of natural fibres can be used to produce large quantities of clean and refined fibres. However, this often results in fibre damage when used alone, thereby affecting the quality of fibres produced, and it generally makes them of insufficient quality for high-performance composite applications. In contrast, the use of biological agents such as enzymes have become a rapidly expanding area of research for producing high quality fibres, but this is still limited to pilot scales. This paper reports the effect of synergizing the salient features of mechanical processing (using a super masscolloider) and enzymatic treatment, on the structure and properties of harakeke (indigenous New Zealand flax) fibre. The cellulose fibres produced are characterized for their potential use as reinforcement in composites. Results show that the combination of mechanical processing with enzymatic treatment could help to overcome the limitations of both processes. [Display omitted] • Natural fibre was produced from harakeke fibre. • Mechanical processing alone is not suitable for quality fibres. • Enzymatic treatment can help to overcome some of the limitations of chemical, physical and mechanical processing. • Synergized mechanical processing and enzymatic treatment of natural fibre holds great potential for composite development. [ABSTRACT FROM AUTHOR]

High‐load bearing bone replacement composite was produced from poly(lactic acid) (PLA), surface modified hydroxyapatite (HA) and glass fiber (GF). Composition dependence and other salient properties of the composites were investigated with respect to the mechanical and dynamic mechanical performance of the composites. Incorporation of modified HA facilitates dispersion, improves bonding, as well as induce heterogeneous nucleation in the PLA matrix. On the other hand, GF greatly influenced the mechanical properties of the composite. The effectiveness coefficient, C, and adhesion factor, A, showed that incorporation of hybrid HA/GF filler helps to improve interfacial interaction due to increased bonding among the components, which produced remarkable enhancement in mechanical performance. For instance, tensile and flexural modulus of the PLA‐HA‐GF composite was raised by 86% and 82%, respectively. In addition, whereas incorporation of HA alone resulted in decreased impact strength (IS) of PLA, the IS of the PLA‐HA‐GF composite improved by 42%. Furthermore, damping of the ternary composite was reduced by 34% whereas the storage modulus is 1273 MPa higher than neat PLA. Therefore, hybrid HA/GF reinforced PLA offers alternative possibility for the fabrication of composites suitable for use in bone replacement and other orthopedic applications requiring high‐load bearing materials. [ABSTRACT FROM AUTHOR]

The demand for hydroxyapatite (HA) is increasing annually due to the growing number of orthopedic patients, but it is a challenge to meet this growing demand without interfering with the integrity of the environment. Here, natural HA was produced from cow bone through ultrasound treatment followed by a calcination process at various temperatures. Characterization of the produced HA was performed by techniques such as thermogravimetric analysis, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction analysis. The elemental composition of the HA was quantified through X‐ray photoelectron spectroscopy, energy dispersive X‐ray spectroscopy, X‐ray fluorescence, as well as carbon, hydrogen, nitrogen, sulfur (CHNS) analysis. The results demonstrate that pure HA was produced after calcination at 950 °C, corresponding to pure HA phase. [ABSTRACT FROM AUTHOR]

The wettability, interfacial shear strength (IFSS), and Weibull characteristics of oil palm empty fruit bunch (EFB) fibers were studied to evaluate the mechanical properties of EFB- and poly(lactic acid) (PLA)-based composites. The fiber surface was modified through ultrasound and poly(dimethyl siloxane) treatment. The effects of treatment on the morphology, wettability, and structure of fibers were examined by scanning electron microscopy, contact angle, and Fourier transform infrared spectroscopy analysis, respectively. In addition, the Weibull characteristic was used to find the variability in strength of the fibers with respect to surface treatment. Furthermore, the IFSS of EFB fiber-PLA sandwich was investigated through single-fiber pull-out test, using a less strenuous technique. The mechanical properties (tensile strength, tensile modulus, flexural strength, and flexural modulus) of the composites were determined through mechanical testing. A comparison was drawn among the properties of PLA, raw EFB fiber-based composites, and treated EFB fiber-based composites. Additionally, the inter- and intrarelationship of fiber treatment, wettability, and IFSS with the mechanical properties of the PLA/EFB composites were also accounted. [ABSTRACT FROM AUTHOR]

Oil palm empty fruit bunch fiber and polylactic acid were used to produce composites by melting cast method. Fiber loading was considered up to 40 wt%. Oil palm empty fruit bunch fibers were treated using ultrasound and polydimethylsiloxane to improve the interfacial adhesion. The structure and surface properties of the fibers were analyzed by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and contact angle measurement. Moreover, Fourier transform infrared spectroscopy, tensile, flexural, X-ray diffraction, contact angle, differential scanning calorimetry, and thermogravimetric analysis were used to investigate composites’ properties. The analysis revealed that polydimethylsiloxane treatment composites show reduced wettability with increased crystallinity. [ABSTRACT FROM AUTHOR]

In vitro biocompatibility of impact modified composites produced from poly(lactic acid) (PLA) and hydroxyapatite (HA) is reported in this study. Surface modification was previously used to facilitate the dispersion of HA in PLA, whereas impact property of the PLA‐HA composites was deliberately enhanced as it was necessary. Herein, osteoblast cell culture assay was used to assess the possible effects of HA surface modification and impact modification on the cell behavior in physiological media. Furthermore, antimicrobial properties of the HA were assessed. Evidence of HA modification was confirmed through elemental and spectroscopic analysis. Incorporation of HA offered better cell attachment and proliferation to the PLA matrix, with significant increase in the cell viability (%). Also, modification of HA did not present obvious cytotoxicity to the PLA‐HA composite. Conversely, incorporation of impact modifier slowed down the rate of cell proliferation on the composite surface but facilitates increased wettability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47400. [ABSTRACT FROM AUTHOR]