Surprising High Hydrophobicity of Polymer Networks from Hydrophilic Components

Abstract

We report a simple and inexpensive method of fabricating highly hydrophobic novel materials based on interpenetrating networks of polyamide and poly(ethyl cyanoacrylate) hydrophilic components. The process is a single-step solution casting from a common solvent, formic acid, of polyamide and ethyl cyanoacrylate monomers. After casting and subsequent solvent evaporation, the in situ polymerization of ethyl cyanoacrylate monomer forms polyamide-poly(ethyl cyanoacrylate) interpenetrating network films. The interpenetrating networks demonstrate remarkable waterproof properties allowing wettability control by modulating the concentration of the components. In contrast, pure polyamide and poly(ethyl cyanoacrylate) films obtained from formic acid solutions are highly hygroscopic and hydrophilic, respectively. The polymerization of ethyl cyanoacrylate in the presence of polyamide promotes molecular interactions between the components, which reduce the available hydrophilic moieties and render the final material hydrophobic. The wettability, morphology, and thermo-physical properties of the polymeric coatings were characterized. The materials developed in this work take advantage of the properties of both polymers in a single blend and above all, due to their hydrophobic nature and minimal water uptake, can extend the application range of the individual polymers where water repellency is required.

Nylon 6,6/graphene nanoplatelet composite films obtained from a new solvent

“…3. The degradation of nylon 6,6 takes place between 350 C and 500 C, as reported by earlier studies, and only about 2% remains at 600 C. 25,26 The weight loss of composites is gradual and the remaining material at 600 C increases with the GnP loading. It is seen that all lms do not decompose at the same temperature, but as GnP concentration increases (except for 0.1 wt% GnP), the decomposing temperature slightly shis to higher values.…”

Biodegradable, Stretchable and Transparent Plastic Films from Modified Waterborne Polyurethane Dispersions

“…This indirectly suggests that the polymers interact with strong hydrogen bonds, leaving no interacting polar groups on the surface of the films. Similar systems were also reported earlier, in which two hydrophilic polymers were hybridized, thereby forming hydrophobic composite films [ 42 ]. The dynamic water contact angle measurements reported in Figure 6 b show that the contact angles change slightly over a period of 2 min under ambient conditions which can be attributed to the evaporation of the droplets rather than droplet absorption into the film or a sudden change in wetting state [ 42 ].…”

“…Similar systems were also reported earlier, in which two hydrophilic polymers were hybridized, thereby forming hydrophobic composite films [ 42 ]. The dynamic water contact angle measurements reported in Figure 6 b show that the contact angles change slightly over a period of 2 min under ambient conditions which can be attributed to the evaporation of the droplets rather than droplet absorption into the film or a sudden change in wetting state [ 42 ]. Separately, the water absorption tests for all the films that extend to a two-week period are reported in Figure 6 c. The pure PU film was very stable and its water uptake remained below 5% compared to pure PVP that completely dissolves in water after a couple of hours.…”

Enhancement of the Processability and Properties of Nylon 6 by Blending with Polyketone

“…Direct modification of PK with diamines resulted in a dramatic increase of the tensile strength of PK [ 27 ]. It was also found that hydrogen bonding between PK and PECA resulted in interpenetrating networks by which wettability and morphology can be controlled [ 28 ].…”