Surface modification and improved adhesion of wood-plastic composites (WPCs) made with different polymers by treatment with atmospheric pressure rotating plasma jet

Abstract

Because of the low polarity of the polymers used for manufacturing wood plastic composites (WPCs), they have low surface energy and their adhesion properties are limited. In this study, the surface modification with atmospheric pressure rotating plasma jet (APPT) of several WPCs made with different polymers is proposed as an environmentally friendly alternative for increasing their hydrophilicity and adhesion. Both the nozzle-WPC surface distance and the platform speed were varied during APPT treatment and only one pass was carried out. APPT treatment of the WPCs made with polyethylene and polypropylene removed most of the wood component and exposed the polymer to the surface, changing their chemistry, surface energy and topography. An improvement in adhesion of the WPCs to different coatings was obtained which was ascribed to the creation of new polar carbon-oxygen moieties, and the removal of wood component on the WPC surfaces. The less surface modification caused by APPT treatment of the WPC made with poly (vinyl chloride) was ascribed to its low wood content and the presence of inorganic fillers.

Fine-tuning of chemical and physical polymer surface modifications by atmospheric pressure post-discharge plasma and its correlation with adhesion improvement

“…1, is created at the outlet of the nozzle, which is directed toward the sample [15]. The post-discharge contains reactive species such as metastables, neutrals, and radicals, but not ionized species [9,16].…”

Comparative surface and adhesion properties of mechanical abrasion, flame and radiation-based surface treated wood plastic composites made with different polymers

“…The spelled plasma was directed to the surface of the WPC placed on movable platform which speed can be varied for changing the length of the treatment. The optimization of the atmospheric pressure plasma torch surface treatment of WPC was carried out in previous study [12], the best experimental conditions were a distance between the WPC surface and the nozzle of 1 cm and a platform speed of 1 m min −1 .…”

“…Among the different surface treatments of WPCs described in the existing literature, the most effective was the surface treatment with chromic acid, but due to environmental concerns it has to be substituted. On the other hand, the surface treatment with O 2 low pressure plasma improved more than two-fold the peel strength, and, during the last few years, additional surface treatments for WPCs made with polyolefin have been proposed including UV/ozone, dielectric barrier discharge, and atmospheric pressure plasma torch, all them improved the surface properties and the adhesion of the WPCs [10][11][12][13][14][15][16][17]. However, a comparison of the effectiveness of these surface treatments in WPCs made with polymers different than PE and PP has not been carried out yet.…”

“…Although there are some publications dealing with the compared effectiveness of mechanical, chemical and flame surface treatments of WPCs made with polyolefin, the influence of the polymer nature and the wood content of the WPC have not been considered yet. Furthermore, the surface treatment of WPC made with PVC has been scarcely studied [12], and the most recent proposed radiation-based surface treatments for WPCs have not been compared. Therefore, in this study the surface modifications and adhesion of three WPCs made with PE, PP and PVC and different wood content treated with mechanical abrasion, flame and several radiation-based treatments (UV/ozone, atmospheric pressure plasma torch, Ar:O 2 low pressure plasma) to acrylic adhesive and coatings of different nature have been carried out.…”

Interaction of Low Cycle Fatigue and Creep in Biomass-filled Plastic Composites

“…BFPCs also need to undergo these tests to meet the standards of use. Currently, the research on BFPCs mostly focuses on their formulation (Naldony et al 2016;Torres-Tello et al 2017;Yáñez-Pacios and Martín-Martínez 2017), interfacial compatibility (Beg 2007;Bera et al 2010), and physical and mechanical properties (Herrera-Franco and Valadez-Gonzalez 2005;Graupner and Müssig 2011;Dikobe and Luyt 2017;Khalid et al 2018). As the study of the connection properties of BFPCs, only the effects of screw type, pilot hole, and material thickness on the strength of the joint have been considered (Özçifçi 2009;Haftkhani et al 2011), whereas research on their fatigue and creep characteristics is scarce.…”