Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Stokes, C. Beth

Committee Member

Street, Jason Tyler

Committee Member

Dowd, Michae

Committee Member

Shmulsky, Rubin

Date of Degree

5-3-2019

Original embargo terms

Visible to MSU only for 3 years

Document Type

Dissertation - Campus Access Only

Major

Forest Resources

Degree Name

Doctor of Philosophy

College

College of Forest Resources

Department

Department of Sustainable Bioproducts

Abstract

A growing market of environmentally-conscious consumers combined with a progression toward ‘greener’ products has caused the wood industry to investigate adhesives containing little to no formaldehyde. This study examines cottonseed proteins’ ability to bind southern yellow pine for plywood applications. Three-ply plywood panels were constructed with varying blends of cottonseed protein isolate (CSPI), soy protein, and phenol: formaldehyde adhesive. Wet and dry shear testing revealed that while the novel adhesives did not perform as well as a commercial control, the CSPI and soy adhesives generated similar shear strengths. Another set of boards were created, varying the CSPI amount added and the ratio of water. The powdered adhesive was spread at 15, 25, 35 and 45 lbs./1000 ft2 and the ratios of protein to water (w/w) were 0.5, 1.0, 1.5 and 2. The resulting boards were tested for internal bond strength (IB) using ASTM D1037 and the treatments were found to not be statistically different. Furthering the study into optimizing the temperature and time, the lowest amount and water ratio were used. The highest mean IB strength was obtained by pressing at 284°F (140 ℃). The highest mean IB strength for time was 10 minutes and produced IB strengths significantly different from all other pressing times. Temperature and time were not found to interact and therefore each affected the mean IB strength individually (p = 0.0553). Using the optimized time and temperature CSPI adhesive, commercial cottonseed meal (CM), water washed cottonseed meal (WW) and defatted cottonseed flour (DF) were used to decide if purity of the protein mattered and if the amount had changed. Using ASTMD1037, it was discovered that WW at 45 lbs./1000 ft2 had the highest mean internal bond strength. Boards made with CSPI adhesive alone and CSPI with guayule were tested for termite resistance, first by using hardwood veneer and later softwood, against the native subterranean termite Reticulitermes spp. Both tests were completed by AWPA E1-16 standard trials. Each was found that CSPI had a performance against termites that was not significantly different from guayule (a known antifeedant). CSPI’s ability to deter termites is a place for future exploration and is not looked at in depth in this study.

URI

https://hdl.handle.net/11668/20951

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