An Insight into the Structural Diversity and Clinical Applicability of Polyurethanes in Biomedicine

In this study, the researchers successfully embellished the surface of halloysite (Ag/HNTs) with silver using halloysite, silver nitrate (AgNO3), and polyvinylpyrrolidone (PVP). The researchers then prepared polyurethane that contained pyridine ring by using 4,4′-diphenylmethane diisocyanate (MDI) and polytetramethylene glycol (PTMG) as the hard chain segment and the soft chain segment of polyurethane (PU), as well as 2,6-pyridinedimethanol (2,6-PDM) as the chain extension agent. This was followed by the preparation of Ag/HNTs/PUs nanocomposite thin films, achieved by mixing Ag/HNTs with different ratios into polyurethane that contains pyridine ring. First, the Ag/HNTs powders were analyzed using energy-dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscopy. Subsequently, Fourier-transform infrared spectroscopy was used to examine the dispersibility of Ag/HNTs in PU, whereas the thermal stability and the viscoelasticity of Ag/HNTs/PU were examined using thermal gravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. When the mechanical properties of Ag/HNTs/PU were tested using a universal strength tester, the results indicated a maximum increase of 109.5% in tensile strength. The researchers then examined the surface roughness and the hydrophobic ability of the Ag/HNTs/PU thin films by using atomic force microscopy and water contact angle. Lastly, antibacterial testing on Escherichia coli revealed that when the additive of Ag/HNTs reached 2.0 wt%, 99.3% of the E. coli were eliminated. These results indicated that the addition of Ag/HNTs into PU could enhance the thermal stability, mechanical properties, and antibacterial properties of PU, implying the potential of Ag/HNTs-02 as biomedicine material.

Section: Introductionmentioning

confidence: 99%

Polyurethane/Nanosilver-Doped Halloysite Nanocomposites: Thermal, Mechanical Properties, and Antibacterial Properties

Sun

Tsou

et al. 2020

“…Additionally, scaffolds based on silk fibroin-collagen loaded with titania nanoparticles were adequate for skin tissue regeneration [ 53 ]. Polyuretanes, due to their wide range of mechanical properties, varying from flexible to rigid materials have been widely used in many industrial and biomedical applications [ 5 ]. Hybrid polyurethane-polylactide porous scaffolds modified with ciprofloxacin were prepared as an antibacterial scaffold for skin regeneration applications [ 51 ].…”

Section: Polymeric Materials With Antibacterial Activitymentioning

confidence: 99%

“…Polymers and polymer-based materials are present in many different applications, being those framed within the biomedicine field, which are perhaps recently receiving more attention [ 5 , 6 ]. Among the functions more desirable for materials used in medicine antibacterial action occupies one of the first positions, because bacterial growth could be prevented on medical devices, prosthetic materials, catheters (urinary or venous catheters) [ 7 ] and surgical masks [ 8 ].…”

Section: Introductionmentioning

confidence: 99%

Polymeric Materials with Antibacterial Activity: A Review

Olmos

González‐Benito

2021

Infections caused by bacteria are one of the main causes of mortality in hospitals all over the world. Bacteria can grow on many different surfaces and when this occurs, and bacteria colonize a surface, biofilms are formed. In this context, one of the main concerns is biofilm formation on medical devices such as urinary catheters, cardiac valves, pacemakers or prothesis. The development of bacteria also occurs on materials used for food packaging, wearable electronics or the textile industry. In all these applications polymeric materials are usually present. Research and development of polymer-based antibacterial materials is crucial to avoid the proliferation of bacteria. In this paper, we present a review about polymeric materials with antibacterial materials. The main strategies to produce materials with antibacterial properties are presented, for instance, the incorporation of inorganic particles, micro or nanostructuration of the surfaces and antifouling strategies are considered. The antibacterial mechanism exerted in each case is discussed. Methods of materials preparation are examined, presenting the main advantages or disadvantages of each one based on their potential uses. Finally, a review of the main characterization techniques and methods used to study polymer based antibacterial materials is carried out, including the use of single force cell spectroscopy, contact angle measurements and surface roughness to evaluate the role of the physicochemical properties and the micro or nanostructure in antibacterial behavior of the materials.

“…Mechanical softening promotes energy dissipation and heat buildup in nanoparticle-reinforced elastomers. Such materials are used widely in engineering applications such as vibration reduction, heat preservation, damping improvement, and the development of composite materials [ 1 , 2 , 3 ]. Polyurethane (PU) elastomers—which are synthetic polymers with repeating units comprising urethane functional groups—play an essential role in industrial manufacture [ 4 , 5 ].…”

Section: Introductionmentioning

confidence: 99%

Stress-Softening in Particle-Filled Polyurethanes under Cyclic Compressive Loading

Zhang

Liu

et al. 2020

Elastomer compositions containing various particulate fillers can be formulated according to the specific functions required of them. Stress softening—which is also known as the Mullins effect—occurs during high loading and unloading paths in certain supramolecular elastomer materials. Previous experiments have revealed that the load–displacement response differs according to the filler used, demonstrating an unusual model of correspondence between the constitutive materials. Using a spherical indentation method and numerical simulation, we investigated the Mullins effect on polyurethane (PU) compositions subjected to cyclic uniaxial compressive load. The PU compositions comprised rigid particulate fillers (i.e., nano-silica and carbon black). The neo-Hooke model and the Ogden–Roxburgh Mullins model were used to describe the nonlinear deformation behavior of the soft materials. Based on finite element methods and parameter optimization, the load–displacement curves of various filled PUs were analyzed and fitted, enabling constitutive parameter prediction and inverse modeling. Hence, correspondence relationships between material components and constitutive parameters were established. Such relationships are instructive for the preparation of materials with specific properties. The method described herein is a more quantitative approach to the formulation of elastomer compositions comprising particulate fillers.