Comparison of Adhesive Properties of Polyurethane Adhesive System and Wood-plastic Composites with Different Polymers after Mechanical, Chemical and Physical Surface Treatment

Abstract

The cost of most primary materials is increasing, therefore, finding innovative solutions for the re-use of residual waste has become a topic discussed more intensely in recent years. WPCs certainly meet some of these demands. The presented study is focused on an experimental analysis of the effect of surface treatment on the adhesive properties of selected WPCs. Bonding of polymer-based materials is a rather complicated phenomenon and modification of the bonded area in order to improve the adhesive properties is required. Two traditional types of surface treatments and one entirely new approach have been used: mechanical with sandpaper, chemical with 10 wt % NaOH solution and physical modification of the surface by means of a MHSDBD plasma source. For comparison purposes, two high-density polyethylene based products and one polyvinyl-chloride based product with different component ratios were tested. A bonded joint was made using a moisture-curing permanently elastic one-component polyurethane pre-polymer adhesive. Standardized tensile and shear test methods were performed after surface treatment. All tested surface treatments resulted in an improvement of adhesive properties and an increase in bond strength, however, the MHSDBD plasma treatment was proven to be a more suitable surface modification for all selected WPCs.

Discharge Plasma Treatment as an Efficient Tool for Improved Poly(lactide) Adhesive–Wood Interactions

“…The obtained improvements were higher than those from [21], where a 67.6% increase in coating adhesion after plasma treatment was reported, as were improvements better than those found from pull-off tests in thermoplastic polyurethane/beech and spruce veneers-1.0 and 2.5 MPa, respectively [44]. A similar apparent enhancement in bondline performance was reported by Novák and co-workers for plasma-treated polyester films in peel tests (270-325%) [28], as well as by Nečasová and co-workers, who observed significant increases in the cohesive failure mode rate for plasma-treated substrates [45]. The above results confirmed the hypothesis that discharge air plasma treatment could be an efficient tool for increasing the SFE of PLA films by changing the chemistry of their surface and subsequently improving adhesion interactions with polar substrates.…”

Enhancement of strength of adhesive bond between wood and metal using atmospheric plasma treatment

“…Different mechanical, chemical and physical surface treatment methods can be applied since the created interaction forces depend on the substrates surface morphology and surface chemistry (Nečasová et al 2019;Sauerbier et al 2018). Plasma treatment (PT) is a fast and versatile physical method for surface modification, which is environmentally friendly because of the absence of organic solvents (Lecoq et al 2008).…”

High-Performance Adhesive Joint Made from Densified Wood

“…Polyurethane adhesive (PU)—GSP PU 902H and GSP PU 902—supplied by GSP Products, Thailand, was selected for this study, in order to fulfill the ranges for the engineering applications of wood joints [ 17 , 18 , 19 ]. A mixture of this commercial PU adhesive with a ratio of GSP PU 902H to GSP PU 902 of 1:3 was prepared at ambient temperature.…”