Modification of Surface Hydrophobicity of PLA/PE and ABS/PE Polymer Blends by ICP Etching and CFx Coating

Abstract

The flow regime inside the channel of 3D printed microreactors is defined by the surface properties of the channel walls. Polylactide (PLA) and acrylonitrile/butadiene/styrene (ABS) are two polymers that are the most common in additive manufacturing using fused filament fabrication, commonly known as “3D printing”. With the aim of developing new materials for the 3D printing of microreactors whose channel surface hydrophobicity could be modified, PLA and ABS were blended with cheaper and widely used polymers-high-density polyethylene (PE-HD) and low-density polyethylene (PE-LD). Polymer blend surfaces were treated with inductively coupled plasma (ICP) and coated by fluorocarbon-based material (CFx) plasma deposition treatment in order to modify surface hydrophobicity. It has been shown that the modification of surface morphology of PLA polymer blends can be achieved by ICP etching and CFx coating, while this was not possible for ABS polymer blends under the conducted treatment conditions. The treated surface of PLA/PE-HD 90/10 showed a contact angle of 121.6° which is 36° higher than the contact angle measured on the untreated surface. Surfaces that have achieved contact angles higher than 120° have an “island like” surface morphology. Samples with higher “islands” showed higher contact angles, that confirmed that the hydrophobicity also depends on the height of the “islands”. Furthermore, it has been found that etching time significantly impacts the contact angle values and surface morphology of the PLA polymer blends, while the CFx coating time does not have significant impact on the surface properties.

Study on Biodegradable Materials From Thermoplastic Starch With the Addition of Nuts Shell

“…Peanut shells also contain a small amount of hemicellulose (12%), which is generally considered hydrophilic, which may also contribute to the highest contact angle (Demirbas, 2006;Aydin and Colakoglu, 2007). Comparing the obtained results to the studies of other authors, PLA has a contact angle from about 70° to even 118° (Lovinčić Milovanović et al, 2020;Bhasney et al, 2017).…”

Modification and Applications of Polylactic Acid

“…Another example is the blending of the PLA and Acrylonitrile Butadiene Styrene (ABS). It is a common combination used in additive manufacturing [7]. The surfaces of the blending polymers are treated with inductively coupled plasma (ICP) and coated with Cystic Fibrosis (CF) materials to modify the surface hydrophobicity.…”

Development of hydrophobic coating on 3D printed ABS samples and surface characterization

“…Less than 0.1% of the dimensions varied. However, moisture absorption contributed to dimensional uncertainty for some polymers, such as polyamides [28]. Using an inductively coupled plasma (ICP) treatment followed by deposition of plasma based on fluorocarbon, surface hydrophobicity was modified on polymer blend surfaces [29].…”