Applicability of Vegetable Oils as a Wood Preservative

Conventional heavy duty wood preservatives have been banned or restricted for some applications due to their mammalian toxicity and their adverse effect on the environment. New, eco-friendly, but nevertheless still effective protection systems, is needed to protect wood in outdoors. Non-toxic vegetable oils can form of a protective layer on the surface of the wood cells which decrease water uptake of wood. For that reason, oils have a good potential as being a wood preservative. However, impregnation with vegetable oils is insufficient to impart adequate biological decay and termite resistance, and indeed the treatment may increase wood’s propensity to burn. In addition, a high level of oil absorption required for good protection make the process impractical and uneconomic to use. The efficiency of the treatment can be improved with using the biocides and oils together. Beside this, usage of modified oils can decrease the retention levels in wood. In this study, applicability of vegetable oils being one of the environment-friendly, biodegradable water repellents on wood treatments was reported. Furthermore, problems related to the use of oils for wood protection, and possible solutions for the problems were discussed.In this study, applicability of vegetable oils as one of the environment-friendly, biodegradable water repellents was reported. Furthermore, problems related to the use of oils for wood protection and possible solutions for the problems were discusse

Effect of Chemical Modification with Maleic, Propionic, and Succinic Anhydrides on Some Properties of Wood Flour Filled HDPE Composites

One of the biggest disadvantages of wood, as a potential reinforcement for thermoplastics, is its hydrophilicity. The aim of this study was to evaluate the effect of chemical modification of wood flour on mechanical, thermal, and fire properties of filled high-density polyethylene composites. For this purpose, aspen flour was modified with maleic, propionic, and succinic anhydrides. The modified wood flour and high-density polyethylene were compounded into pellets by single-screw extrusion, and test samples were prepared by injection molding. Tensile and flexural tests, impact testing, limiting oxygen index, TGA, and SEM analyses were conducted both for modified and un-modified samples. Based on the test results, chemical modification enhanced the properties of thermoplastic composites. Depending on the chemical concentrations, the flexural, tensile, and impact strengths of the modified flour filled HDPE composites were improved slightly, while the tensile and flexural moduli of the samples were increased significantly. The limiting oxygen index (LOI) levels of samples with modified wood flour were slightly improved, and succinic anhydride provided higher LOI levels compared to the samples with other anhydrides. This showed that the composites filled with chemically modified wood flour were slightly more thermally stable than control samples. It appears that wood flour modified with maleic, propionic, and succinic anhydrides can be successfully utilized as filler in polymer matrices

IMPROVING OF THE IMPREGNABILITY OF REFRACTORY SPRUCE WOOD BY BACILLUS LICHENIFORMIS PRETREATMENT

In this study it was aimed to improve impregnability of spruce (Picea orientalis L.) wood with bacteria (Bacillus licheniformis A1) pretreatment, using copper/chromium/arsenic Type C (CCA-C) and copper azole Type A (CBA-A). The effects of Bacillus licheniformis A1 on weight loss, copper uptake, and compression strength of samples were determined. Weight loss was slightly changed by bacterial degradation in all test groups. The best copper uptake cases were 1466 ppm for CCA-C and 2730 ppm for CBA-A. Improvement on copper uptake with bacteria pretreatment was in a range of 18 to 103% compared to control samples. Compression strength was decreased by bacterial degradation. However strength losses might be acceptable for several construction applications. Bacillus licheniformis A1 seems to have a good potential for increasing the permeability of spruce wood