Synthesis and Characterization of Biopolyol-Based Waterborne Polyurethane Modified through Complexation with Chitosan

Abstract

In this study, a series of castor oil-based anionic waterborne polyurethane (CWPU) systems, which it has been suggested may be suitable for use as green elastomers with diverse applications in films and coatings, was prepared by modified with O-carboxymethyl chitosan (CS) as not only a reinforcing filler, but a chain-extender of polyurethane prepolymer to enhance the properties of polyurethanes. Moreover, not only was the system obtained with castor oil-based polyol in the absence of a catalyst, but it was maintained with low viscosity by using acetone instead of toxic methyl ethyl ketone (MEK) during the synthesis process. The sizes, zeta potential, chemical formation, and morphology of the CWPU-CS composites had been investigated by dynamic light scattering (DLS), infrared spectroscopy (IR), and scanning electron microscopy (SEM). Moreover, the results show that the modification allows to enhance storage/loss modulus, tensile properties, thermal stability at high temperature, and biocompatibility of CWPU and CWPU/CS nanocomposites according to various contents of CS.

Chitosan Oligosaccharide Based Waterborne Polyurethane with UV Resistance and Oxidation Resistance for Functional Fabric

“…The reason for the favorable mechanical properties of CWPUs is the addition of chitosan oligosaccharide improves the content of hard segments in polyurethane, resulting in the increase of stress and initial modulus. [ 40 ] In addition, COS causes a large number of chemical cross‐linking structures in polyurethane molecules (Figure 2i), which effectively limits the molecular chain slippage under tension. It means that more force is required to achieve the same strain.…”

Incorporation of Chitosan in Polyurethanes Based on Modified Castor Oil for Cardiovascular Applications

“…Biocompatibility is not affected, as it is a surface property, while the mechanical properties are bulk properties. Choi et al synthesized nanocomposite polymers with waterborne polyurethane (WPU) and chitosan, and for the mechanical properties, they observed that the inclusion of chitosan increased their strength and elongation, and the authors attributed this to the hard and soft segments due to the addition of Ch as a chain extender because the Ch chains are stiffer and can affect the elasticity of the resultant films by cross-linking and hydrogen bonding with CWPU chains [ 26 ]. The inclusion of Ch, which is a stiffer molecule, as a filler in the matrix affects the mobility of the chain, which reduces the tensile strength and elongation [ 7 ].…”