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Characteristic of polypropylene nanocomposite material reinforcement with hydroxyapatite for bone replacement

Obaid M. N., Sabr O. H., Hussein A. A.

Journal of Achievements in Materials and Manufacturing Engineering

2021

Vol. 104, nr 1

21--30

Purpose: Human bone suffered some degeneration due to age and accidents; therefore, there are many interests in the prepared synthetic bone with properties nearer to natural bone. The present study prepared a nanocomposite of polypropylene reinforced with different weight fraction of Nano hydroxyapatite (HAp) to be used as a bone replacement with good biological properties that enhanced the growth of osteoplastic cells and enhance the prevention of clots and coagulates creation. Design/methodology/approach: Nanocomposite from polypropylene reinforced with different weight fraction of Hydroxyapatite (HAp) (1,2 and 3) % prepared by first dispersion Nano hydroxyapatite insolvent and then mixing with a pellet of polypropylene by the twin-screw extrusion process, the current research study the surface properties ( atomic force microscopy (AFM), contact angle test) Moreover, it studied the characteristics of prepared nanocomposite materials (Differential Scanning Calorimetry (DSC), Field Emission-Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared (FTIR)). Findings: The AFM results show the surface roughness decreased with increasing content of HAp, which diminished the chance of creation clots and coagulates on it. The contact angle results referred to polypropylene behaviour transformed from hydrophobic to hydrophilic with addition HAp that permission to grow the osteoplastic cell on it, so the healing process is accelerated. Moreover, the FE-SEM images revealed uniform distribution and good bonding between polypropylene and Hydroxyapatite. The thermal properties were measured by the DSC test showed the melting temperature, and the enthalpy of melting (indicated to increase the crystalline structure per cent) are increased with increasing the percentage of Hydroxyapatite. Research limitations/implications: This research studied the characteristics of nanocomposite materials prepared by three steps (dispersion by ultrasonic device, manually mixed and melting and mixing by twin extruder) which can be used as a bone replacement. However, the main limitation was the uniform distribution of nano-hydroxyapatite within the matrix. In a further study, the cytotoxic test can be tested to study the effect of prepared nanocomposite on living cells’ growth. Practical implications: The interest object is how to connect among different properties to prepared bone replacement with good properties and biocompatibility that made able to stimulate the growth and healing process. Originality/value: The nano-hydroxyapatite is a biomaterial that has a composition similar to the natural mineral phase of the bone and does not have any negative effect, which enhanced the growth of osteoplastic cells and decreased the clots and coagulates creation; therefore, nano-hydroxyapatite is used to decrease the surface roughness which decreased the chance of coagulation creation and to enhance the hydrophilic properties.

Plumbogummite group minerals in Lower Devonian placoderm sandstones from Podłazie Hill, Holy Cross Mountains, Poland

Kruszewski Ł., Dec M.

Geological Quarterly

2018

Vol. 62, No. 2

353--360

Samples of Lower Devonian vertebrate-bearing placoderm sandstones collected in a quarry at Podłazie Hill in the Holy Cross Mountains, central Poland, were found to contain numerous white and brownish aggregates of an unknown composition. Powder X-Ray Diffraction study has shown them to comprise plumbogummite group minerals (PGM). Gorceixite is most common, usually forming compact/porous aggregates. They are either found in voids within the quartz-rich zircon-, muscovite- and biotite-bearing matrix, or as a complete replacement after bone remnants. Goyazite aggregates are similar but rarer. Strontian crandallite is found as tiny zoned crystals closely associated with compact gorceixite (in the sandstone matrix) or as cores of fine-grained gorceixite aggregates (within the bones). All of the PGMs are enriched in Ce and La with two analyses marginally within the compositional field of florencite-(Ce). Ca enrichment, elevated F content and abundance of goyazite within the bone replacement suggest the primary bone apatite group as the source of these elements. Tuffites and claystones associated with the sandstones are probably the source of Ba and Sr, while Pb is possibly derived from local Devonian mineralisation.