Date of Award

5-2002

Level of Access

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Forest Resources

Advisor

Barry Goodell

Second Committee Member

Roberto Lopez-Anido

Third Committee Member

Stephen Shaler

Abstract

When wood products are exposed to environmental conditions conducive to biodeterioration, wood preservation becomes a necessity, especially when long-term utilization is desired. Although considerable literature exists on the treatment of laminated timbers and wood composites with wood preservatives, almost no information is available on the exposure of Fiber Reinforced Polymer (FRP) composites to wood preservative chemicals. In this work, FRP material was treated with common preservative chemicals and the effect of wood preservative treatments on mechanical properties of FRP material were investigated. Although the longitudinal elastic modulus was unaffected, some longitudinal strength losses were recorded for CCA and CDDC (water borne) treated FRP coupons. These results were supported by Scanning Electron (SEM) and light microscopy analyses of single glass fibers taken from preservative treated FRP coupons. A further study evaluated the susceptibility of E-glass fiber reinforced polymer (FRP) /phenolic pultruded composite material to fungal degradation. Since the phenolic FRP material was designed for use as reinforcement with wood, two common wood decay fungi, a brown rot and a white rot, were chosen for exposure of the FRP material. Light, fluorescent and Scanning Electron Microscopy (SEM) indicated that both wood decay h g i actively grew and penetrated into the FRP material, especially in high-void content areas. The experimental results indicate that, the mechanical property evaluation technique (ILSS) is promising and sensitive enough to detect the effects of fungal degradation in phenolic FRP materials. The durability of adhesive bonds on wood/FRP interfaces poses a continuing problem for the wood products industry. Wood preservative chemicals are known to interfere with adhesion mechanisms between wood laminates as well as wood/FRP interfaces. The purpose of the third part of this study was to determine the effects of various wood preservative treatments and manufacturing processes (pre- and post-treatment) on wood/FRP bond durability, shear strength and surface energy characteristics of wood and phenolic FRP material. While pre-treatment of individual laminates with oil borne (copper naphthenate, creosote and pentachlorophenol) and water borne (CCA and CDDC) preservatives increased the delamination between the wood and FRP, the post treatments had limited effects on delamination.

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