Synthesis and Physicochemical Behaviour of Polyurethane‐Multiwalled Carbon Nanotubes Nanocomposites Based on Renewable Castor Oil Polyols

Abstract

Polyurethanes (PUs) are high performance materials, with vast industrial and engineering applications. In this research, effects of Multiwalled Carbon Nanotubes (MWCNTs) on physicochemical properties of Castor Oil based Polyurethanes (COPUs) were studied. MWCNTs were added in different weight percentages (0% to 1% wt) in a castor oil based polyurethane (COPUs-MWCNTs) nanocomposites. The composition, structure, and morphology of polyurethanes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), and element detection by energy dispersive spectroscopy (EDX) analysis, respectively. Thermal stability was studied by thermogravimetric analysis (TGA). Barrier properties and surface area studies were investigated by nitrogen permeability machine and BET technique. Mechanical properties were calculated by tensile universal testing machine. Results showed well dispersed MWCNTs in polyurethane matrix at different weight percentages. The best results were obtained with 0.3 wt% of MWCNTs in the composite. Surface area studies revealed presence of very few pores which is in a good agreement with barrier permeability, reduced up to ~68% in 1 wt% and ~70% in 0.5 wt% of MWCNTs in polymer matrix, with respect to pure COPUs samples.

Controlled release of nitrogen‐source fertilizers by natural‐oil‐based poly(urethane) coatings: The kinetic aspects of urea release

“…A broad peak was observed around 20°; this was characteristic of the standard MDI used in polymer synthesis and showed that the material presented a semicrystalline structure. According to Ali et al ., this was related to the existence of short‐range regularly ordered structure of both the hard and soft domains along with the disordered structure of the amorphous phase of the PU matrix, as shown in the values of the reflection plane with interchain spacings of 4.392 and 4.388 Å for castor oil PU and soybean oil PU, respectively. The coating sample showed a low crystallinity profile (only BaSO 4 peaks were seen in soybean oil PU) …”

Preparation, Characterization and Mechanical Properties of Bio-Based Polyurethane Adhesives from Isocyanate-Functionalized Cellulose Acetate and Castor Oil for Bonding Wood

“…Since their discovery by Otto Bayer and co-workers in 1937 [11], polyurethanes have become one of the most outstanding polymers as they exhibit a high performance and versatility, being employed in a vast range of industrial and engineering applications such as foams [12,13], coatings [14], medicinal products [15,16] or adhesives [17], among others. This wide variety of applications is associated to their superior properties, including excellent corrosion, solvent and chemical resistance, high mechanical strength, low temperature flexibility, adhesion, suitable curing rates, chemical structure versatility, etc.…”

“…In fact, a wide range of natural oils have been considered as feasible choices to synthesized segmented polyurethanes [32,33], such as linseed or rapeseed [34], sunflower [35], canola [36], but principally soybean [29] and castor oil [14,15]. Castor oil belongs to the vegetable oil minority that exhibits bearing hydroxyl group [15], which, along with double bond presence [37], makes it an appealing resource for producing polyurethanes. In particular, some castor oil-based polyurethane formulations have been previously proposed as eco-friendly solventless adhesives [20,38].…”

Synthesis and characterization of multiwall carbon nanotube/waterborne polyurethane nanocomposites

“…Well‐dispersed CNTs in the polymer matrix as well as the strong interfacial interaction between polymer and CNTs enhance the stress transfer between polyurethane matrix and MWCNTs, and, as a result, the resistance of the polymer to deformation will increase . The main reason for this improvement can be ascribed to the reinforcing effect of CNTs and hydrogen bonding between functionalized CNTs and polymer in nanocomposites . On the other hand, CNT agglomeration destroys the structure of the polymer matrix and subsequently causes poor reinforcement .…”