Algal Decay Resistance of Conventional and Novel Wood-Based Composites

Abstract

Measures of the resistance to algal decay of conventional (medium density fiberboard [MDF] and plywood) and novel wood-based composites (WPC) were investigated in the same or varying wood species by using an artificial accelerated test with four mixed algal suspensions (Chlorella vulgaris, Ulothrix sp., Scenedesmus quadricauda, and Oscillatoria sp.). The morphology characterization of the surface and fracture of the specimens was analyzed using scanning electron microscopy (SEM) and a digital instrument. The pH value and the mass loss rate of the different wood species were also tested. The results showed that the algal resistance of the MDF and plywood were superior to that of the WPC of the same wood species. Furthermore, the algal resistance capacity of WPC made from various wood species were ranked as: Liquidambar formosana > Cunninghamia lanceolata and Melaleuca leucadendra > Ricinus communis > Eucalyptus grandis × E. urophylla and Pinus massoniana. There was a close relationship between the pH value and the algal resistance level; as the pH value increased, the alga resistance of the WPC also increased. The algal colonization only had a negative effect on the appearance of the samples.

Wood Plastic Composites: Their Properties and Applications

“…Termites and other microorganisms, such as mold and fungi, can decrease the esthetic quality and mechanical strength of WPCs through discoloration and degradation by chemically altering the structures of lignin, hemicellulose, and cellulose fibers in the wood [12,13]. However, algae colonization only affects the outer appearance of the WPC instead of the inner interfacial bonding [14]. To promote the quality and prolong the service time of the entire WPC structure, more attention needs to be paid to improving the biological durability during the engineering of the Engineered Wood Products for Construction composites in the future.…”

“…PE-based WPCs containing Parthenium argentatum, Parthenium incanum, and Parthenium tomentosum fibers displayed better termite resistance compared to the WPCs containing pine fiber, with mass losses of 7%, 6%, and 5%, respectively. PVC-based WPCs filled with different wood species exhibited varying resistance levels to four common biological organisms, including algae, fungi, mold, and termites, as shown in Figures 4-7 [11,14,20]. Several functional chemical extractives naturally present in wood varieties can either facilitate or inhibit the biodeterioration of WPCs.…”