Preparation and characterization of diatomite and hydroxyapatite reinforced porous polyurethane foam biocomposites

Abstract

Porous three-dimensional (3D) polyurethane-based biocomposites were produced utilizing diatomite and hydroxyapatite as fillers. Diatomite and Hydroxyapatite (HA) were utilized to reinforce the morphological, chemical, mechanical, and thermal properties of polyurethane foam (PUF). Diatomite and Hydroxyapatite were added into polyurethane at variable percentages 0, 1, 2, and 5. The mechanical properties of PUF were analyzed by the compression test. According to the compression test results, the compressive strength of the polyurethane foam is highest in the reinforced foam at 1% by weight hydroxyapatite compared to other reinforced PUFs. Scanning electron microscopy (SEM) images presented structural differences on foam by adding fillers. Functional groups of PUF were defined by Fourier Transform Infrared Spectroscopy (FTIR) and the thermal behavior of PUF was studied with Thermogravimetric Analysis (TGA). The obtained results revealed that PUF/HA biocomposites indicated higher thermal degradation than PUF/Diatomite biocomposites. The bone can be regarded as a composite substance composed of inorganic minerals mostly formed through hydroxyapatite (HA), which reinforces the bone structure and supplies mechanical strength and moreover an organic matrix consisting of type I collagen. Bone is good at self-regeneration, but the natural healing mechanism is difficult when significant bone loss, so medical implants are generally utilized to overcome the defect of bone. The temporary 3D scaffold, according to the bone tissue engineering approach, plays a significant role in controlling osteoblast functions as well as a fundamental role in guiding the new formation of bone into preferred forms 1. Scaffolds for bone regeneration serve primarily as substrates for binding and proliferation of osteogenic cells. Thus, like bone grafts, three-dimensional biodegradable materials with a porous structure were of big interest not only for their structural and composition similarities to the natural bone but also for their original functional properties, like greater surface area, and high mechanical strength 2. The most studied synthetic biodegradable polymers studied for bone tissue engineering include polylactic acid (PLA), polycaprolactones (PCL), polyglycolide (PGA), and polylactic-co-glycolic acid (PLGA) 3,4. However, when artificial biodegradable polymers are used, the right equilibrium among the rate of tissue regeneration and in vivo degradation is hard to accomplish. For this reason, other polymers, especially polyurethanes, can be utilized to produce scaffolds for the regeneration of bone tissue. The use of polyurethane for scaffolding is probable to achieve a much wider range of morphological and mechanical characteristics compared to mostly used biodegradable polymers 5. Polyurethanes (PU) are classically produced by polyaddition reactions of isocyanates with polyols (polyalcohols). Based on the formulation, a wide property spectrum from elastomer to rigid foams are readily designed and synthesized 6-8. Currently, they are...

A Green Method for Synthesis of Silver-Nanoparticles-Diatomite (AgNPs-D) Composite from Pineapple (<i>Ananas comosus</i>) Leaf Extract

“…In the biomedical field, diatomite is applied as a drug delivery material [11], biosensing [12], a filler for making scaffold and bone tissue regeneration [13]. As a filler for scaffold and bone tissue regeneration, diatomite is used for reinforced porous polyurethane foam (PUF) [14] and chitosan composite membrane [15]. The addition of diatomite increases the mechanical strength and water uptake capacity of the polymer.…”

Biobased Castor Oil-Based Polyurethane Foams Grafted with Octadecylsilane-Modified Diatomite for Use as Eco-Friendly and Low-Cost Sorbents for Crude Oil Clean-Up Applications

“…When DE particles are modified with C18 silane, as shown in Figure 2 (b1–b3), they provide visual evidence of DE retaining disk-shaped regular and irregular particles. Moreover, incorporating C18 silane-modified DE particles during the formulation of PU foam developed a roughness on the surface that can be seen in Figure 2 (c1–c3) [ 56 ]. This surface roughness is attributed to the presence of modified DE particles on the smooth skeleton of the PU foam matrix.…”

Preparation of Diatom-Doped Bio-Nanocomposite Materials for Bone Tissue Scaffolds

“…It was determined that the OH groups of HAp in the BTS-1, BTS-2, BTS-3 and BTS-4 scaffolds were located in the asymmetric stretch band at 3288, 3290, 3291, 3284 cm -1 levels, and in the asymmetric bending band at 1647, 1652, 1652, 1647 cm -1 levels, respectively. It was determined that the PO 4 -3 groups of HAp were located in the asymmetric stretch band at the levels of 559, 558, 558,559 cm -1 and in the asymmetric bending band at the levels of 1016, 1012, 1015, 1016 cm -1 , respectively [60][61][62] .…”

“…The peak in the range of 1076-1100 cm-1 of the diatom shows the vibrations in the asymmetric Si-O Si bonds, and the peak in the range of 750850 cm -1 shows the vibrations in the symmetrical Si-O-Si bonds. The peak at 600 cm -1 levels is due to the crystal structure of the diatom [60][61][62][63][64] .…”