Behzad Pourabbas’s research while affiliated with Sahand University of Technology and other places

In 3D printing technology, unwanted resin properties such as low mechanical, thermal, electrical, and biocompatibility can be enhanced by using proper fillers. In this study, sucrose urethane microparticles, acrylic modified are used to improve the properties of the final object without losing other properties such as printing resolution. Modification is confirmed by FTIR spectroscopy and hydrogen bonding index enhancement after modification of the urethane filler. Filler particles are reduced in sizes by modification followed by ball‐milling as is confirmed by scanning electron microscopy. When the filler content is 2.5 wt%, mechanical tensile and flexural modulus increase compared to the neat resin however, increases the brittleness of the photo‐cured samples. Thermal degradation temperature is lifted up for 2.5–5.0 wt% of the filler loading in the resin. Improved dimensional accuracy and detailed printing in higher resolution, due to the physical effect of the filler particles, can also be achieved in real 3D‐printed object as is explored. Highlights High‐resolution 3D printing, by random geometry of filler particles in the resin. Scattering from polyurethane foam microparticles lead to high‐resolution printing. Acrylate‐modified polyurethane filler particles provide resin compatibility. Polyurethane filler leads to higher resolution with enhanced mechanical properties.

Vat photopolymerization-based three-dimensional (3D) printing techniques have been used as an efficient method for complex and special geometries in various applications. Composites are also a group of polymer materials that are obtained by adding a reinforcing component such as filler, fibres with different origins. Therefore, the development of 3D printable composites is paramount due to their high precision and speed of production. Glass beads (GBs) have been favorites as economical reinforcement agents for their chemical stability, water resistance in acidic environments, dimensional stability, and eco-friendly properties. In this study, 3D printable composites based on coated glass beads (CGBs) have been prepared. First, the beads are coated with ultraviolet (UV) curable resins to improve the interface with the polymer matrix. Then, CGBs are mixed with 3D printing resin and formulated for digital light processing (DLP) printing. The coating process is checked by scanning electron microscopy (SEM), and the mechanical properties of the 3D-printed composite structures have been evaluated by bending and compression tests. Also, the fracture behavior of cured resin has been checked with SEM. Mechanical property investigations have shown the success of the 3D printing of the CGBs into a photopolymer resin (PR) composite with behavior modification and compatibility of the interface with the matrix in practice.

Sustainable composites based on blends from polypropylene (PP) and recycled polyethylene terephthalate (RPET) and wood flour (WF) were prepared under industry‐relevant conditions by melt extrusion, followed by continuous drawing through spinnerets. Maleic anhydride grafted polypropylene (PP‐g‐MA) was employed to improve the compatibility between matrix and WF. The effects of incorporation of WF and RPET microstructure on the morphological features, rheological measurements, and mechanical properties were investigated. The drawing process converted elliptical RPET phase into highly oriented microfibrillar structure, as characterized by means of scanning electron microscopy (SEM). The highly oriented blend (HOB) represented nonterminal behavior due to the presence of physical networks and enhanced surface area of microfibers for chemical interactions. The tensile strength of neat PP increased by the addition of WF and the existence of microfibrillar RPET phase, whereas the microstructure of RPET had more pronounce effect. The tensile strength and elastic modulus of PP reinforced by WF and oriented RPET improved by 65% and 92%, respectively, demonstrating the high potential of this environmental‐friendly reinforcement method to intensify the mechanical properties of PP.

https://authors.elsevier.com/a/1gJhV8MvHg-a4o

Objective As a progressive chronic condition, osteoarthritis (OA) causes substantial pain and impairment. Secrete proinflammatory cytokines are essential mediators involved in the pathophysiology of OA. In this regard, the clinical effectiveness of autologous conditioned serum (ASC) has been shown through its injection into OA tissues. This study aimed to assess the effectiveness and concentration level of ACS components produced by Nano-carbon glass beads. Intravenous whole blood was obtained from each New Zealand male rabbit by 10-ml syringes, comprising 33 medical-grade Nano carbon-coated glass beads. Serum retrieving was performed after 6–8 h incubation (37 C, 5% Co 2 ), and then centrifuged. The ACS was then injected into OA rabbits to assess its function. Results Glass beads-prepared ACS coated with Nano-carbon, induced a huge amount of cytokines and growth factors production. The concentration level of anti-inflammatory cytokines and proinflammatory cytokines was improved throughout Nano-carbon coated glass beads stimulation. ACS also shortened the recovery time and improved the function and mobility of OA rabbits. We showed that ACS improved the function and mobility of OA rabbits, as well as shortened the recovery time. It is suggested that further studies evaluate this effectiveness.