Source: MISSISSIPPI STATE UNIV submitted to NRP
EVALUATION OF CAPROLACTAM AS A BULKING AGENT TO DIMENSIONALLY STABILIZE WOOD
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
1019503
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jul 1, 2019
Project End Date
Jun 30, 2023
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
MISSISSIPPI STATE UNIV
(N/A)
MISSISSIPPI STATE,MS 39762
Performing Department
Forest Products
Non Technical Summary
Two major problems with wood products when used for various applications are susceptibility to biodegradation and dimensional instability when exposed to fluctuating moisture conditions. There currently are several wood preservatives that provide reasonable protection against biodeterioration. However, these traditional treatments do not impart any appreciable dimensional stability which results in excessive checking, splitting and warping during normal use. Consequently, there is a need for new treatments that will improve the performance of wood products. One method of imparting dimensional stability to wood is to treat it with compounds that bulk the cell wall. In this regard, polyethylene glycol (PEG) has been used for this purpose, (Stamm, A.J., 1964). Although PEG is a good bulking agent for wood it does not impart appreciable decay resistance except at very high retention levels (Stamm, A.J., Bacchler, R., 1965.Historically, one of the major uses for PEG was to stabilize wood that has been submerged in water for decades. In this regard, a recent study by Broda and Mazela (2017) showed that PEG is not entirely satisfactory for preserving water logged wood. In this regard the referenced a study by Almkvist andl Persson (2007), which showed that the chemical reactivity of PEG with substrates in wood can accelerate further wood degradation. Consequently, new treatments are needed for this application, as well as other potential uses.
Animal Health Component
0%
Research Effort Categories
Basic
40%
Applied
0%
Developmental
60%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5110650200070%
5110650110330%
Goals / Objectives
The objectives of this proposed research are to:Determine the potential for using caprolactam as a wood treatment to improve dimensional stability.Determine the potential of using caprolactam to improve the decay resistance of wood.Explore methods to reduce the leachability of caprolactam from treated wood.
Project Methods
The degree of dimensional stabilization imparted by caprolactam treatment will be determined by pressure treating southern pine sapwood wafers with various concentration of aqueous solutions. The treated wood will then be evaluated for volumetric shrinkage and swelling of samples after exposure to a range of relative humidity conditions. Studies will also be carried out to determine the minimum dimensional stabilization required to minimize checks and splits that occur when the treated wood is subjected to cyclic high and low moisture content conditions.The efficacy of caprolactam treated wood against wood decay fungi will be determined for both brown rot and white rot fungi using AWPA Standard E 22. In addition, the efficacy of caprolactam treated wood against termites will be determined using AWPA Standard E1.Caprolactam is water soluble so it would be desirable to develop methods to reduce the leachability of this compound when treated wood is exposed to wet environments. In this regard some preliminary experiments suggest that a combination of caprolactam and furfural may have potential. Other approaches will also be explored.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Wood preserving industry, building contractors, and wood scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project provided training for a graduate student in conducting laboratory termite tests,decay tests, andpressure treatment processes for wood. How have the results been disseminated to communities of interest?Since only preliminary results are currently available, no results were disseminated. What do you plan to do during the next reporting period to accomplish the goals?Additional additives to caprolactam formulations will be evaluated to enhance fixation of caprolactam and dimensional stability of the treated wood. Depletion studies will be conducted to evaluate the effect of various additives on caprolactam leaching.

Impacts
What was accomplished under these goals? Caprolactam in combination with furfuryl alcohol was evaluated as a bulking agent for wood to reduce the swelling and shrinking of pine wood. Preliminary results indicate that this combination provides enhanced dimensional stability at fairly low concentrations. A laboratory termite test was conducted to evaluate the efficacy of caprolactam treated wood. The results showed that caprolactam completely inhibited termite attack at a retention level of 0.4pcf.

Publications


    Progress 07/01/19 to 09/30/19

    Outputs
    Target Audience:Wood preserving industry, building contractors, wood scientists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One Ph.D student participated in this project and provided training in methods for measuring dimensional stability of wood. In addition, training was provided in soil block decay test methodology. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?Additional studies will be conducted to further evaluate the amount of dimensional stability and decay resistance provided by caprolactam.

    Impacts
    What was accomplished under these goals? Caprolactam was evaluated as a bulking agent for pine wood to reduce the amount of swelling when exposed to water. Samples were treated with caprolactam at concentrations ranging from 0 to 20 % and then evaluated for dimensional stability by measuring the amount of swelling when exposed to relative humidities ranging from 0 to 100%. It was found that the swelling was progressively reduced as the treating solution concentration increased, resulting in a 55% reduction in swelling at the highest concentration level. The fungicidal activity of caprolactam was evaluated in a soil block decay test with the brown rot fungus Gloeophyllum trabeum. It was found that caprolactam linhibited wood decay at a level of 0.4 pcf.

    Publications