David P. Harper, Ph. D.
Forest Products Center
Phone: (865) 946-1121
visit our website
In the Harper group at the Tennessee Forest Products Center, we are involved in the development of technologies that will foster the use and economic viability of materials derived from renewable sources for a sustainable and more secure future. Materials derived from plant based sources inherently are renewable, require less energy to process, and have fewer end of life disposal issues than nonrenewable sources. We are using these materials not only to replace fossil based equivalents, but in new applications that are made possible because of the unique characteristics of the plant based materials.
Our research focuses on three main areas: novel processing of materials to improve efficiency and performance, improving interfacial interaction between natural fibers with adhesives and matrices, and development of completely new materials. In the area of material processing, we have successfully used electron beam irradiation to reduce the amount of energy consumed in the manufacture of wood composites by up to 50%. The materials produced had improved durability and creep performance. Novel adhesives and additives were developed in our lab to be compatible with the wood materials and e-beam processing technology to make this feasible. Further, we are using our knowledge of renewable materials processing and interfaces to generate carbon fibers from a 100% renewable feedstock, lignin. This allows us to turn a low value byproduct of papermaking or a biorefinery into a high value commodity. Please contact me for more information.
P. Tingaut, N. S. Çetin, N. Özmen, N. Henry, D. P. Harper, M. Dadmun, G. Sèbe. 2009. The acetylation of cellulose nanowhiskers with vinyl acetate under moderate conditions. Macromolecular Bioscience. 9(10): 997-1003. 10.1002/mabi.200900073.
J.-W. Kim, D. P. Harper, A. M. Taylor. 2009. Effect of extractives on water sorption and durability of wood-plastic composites. Wood and Fiber Science. 41(3): 279-290.
Q. Cheng, S. Wang, D. P. Harper. 2009. Effects of process and source on elastic modulus of single cellulose fibrils evaluated by atomic force microscopy. Composites Part A. 40(5): 583-588. doi:10.1016/j.compositesa.2009.02.011.
J.-W. Kim, D. P. Harper, A. M. Taylor. 2009. Effect of wood species on the mechanical and thermal properties of WPCs. Journal of Applied Polymer Science. 112: 1378-1385.
D. P. Harper, M. P. Laborie, M. P. Wolcott. 2009. The Impact of Polypropylene-graft-Maleic Anhydride on the Crystallization and Dynamic Mechanical Properties of Isotactic Polypropylene. Journal of Applied Polymer Science. 111: 753-758.
J.-W. Kim, D. P. Harper, A. M. Taylor. 2008. Effect of wood species on water sorption and durability of wood plastic composites. Wood and Fiber Science. 40(4): 519-531.
C. Sattler, N. Labbe´, D. P. Harper, T. Elder, T. Rials. 2008. Effects of hot water extraction of oriented strand board (OSB) wood flakes. Clean. 36(8): 674-681.
P. Tingaut, N. Henry, T. G. Rials, D. P. Harper, M. Dadmun. 2008. Compatibilization of natural fibers with synthetic polymers using triblock copolymers as coupling agents. Macromolecular Chemistry and Physics. 209(8): 832-845.
İ. Çelen, D. P. Harper, N. Labbé. 2008. A multivariate approach to acetylated poplar wood samples using NIR. Holzforschung. 62: 189-196.
J. Konnerth, D. P. Harper, S.-H. Lee, T. G. Rials, W. Gindl. 2008. Adhesive penetration of wood cell walls investigated by scanning thermal microscopy. Holzforschung. 62(1): 91-98.
M. Gaugler, W. J. Grigsby, D. P. Harper, T. G. Rials. 2007. Chemical imaging of the spatial distribution and interaction of tannin dispersal in bioplastic systems. Advanced Materials Research. 29-30: 173-176.
D. P. Harper, M. P. Wolcott. 2006. Chemical imaging of wood-polypropylene composites. Applied Spectroscopy. 60(8): 898-905.
N. Labbe´, D. P. Harper, T. G. Rials, T. Elder. 2006. Chemical structure of wood charcoal by infrared spectroscopy and multivariate analysis. Journal of Agricultural and Food Chemistry. 54: 3492-3497.
T. Elder, N. Labbe´, D. P. Harper, T. G. Rials. 2006. Time domain-nuclear magnetic resonance study of chars from southern hardwoods. Biomass & Bioenergy. 30: 855-862.
D. P. Harper, M. P. Wolcott. 2004. Interactions between coupling agents and lubricants in wood-polypropylene composites. Journal of Composites A. 35:385-394.
D. P. Harper, G. F. Dorsey, T. Stortz, T. G. Rials, W. L. Griffith. 2009. Dual-cure low-temperature and electron-beam curable resins for wood composites. ANTEC. Chicago, IL.
D. P. Harper, R. J. Sammons, N. Labbe´, T. G. Rials, and T. Elder. Novermber 20 & 21, 2008. Adding value to cellulosic ethanol. Contribution des sciences and industries du bois aux defies du development durable, 5th Colloque Sciences and Industries du Bois, ARBORA. Bordeaux, France.
D. P. Harper, T. G. Rials, G. Dorsey, and W. L. Griffith. November 6, 2008. Opportunities for Low-Temperature Radiation Cured Adhesive in Natural Fiber Based Composites. Pacific Rim Biobased Composites Symposium. Rotorua, New Zealand.
D. P. Harper, N. Labbé, T.G. Rials, G. Dorsey, S. Bowman, W. L. Griffith, T. Elder. June 3-7, 2007. High-energy electron beam affect on lignocellulosic materials. SAMPE 2007, Baltimore, MD.
W. L. Griffith, G. F. Dorsey, D. P. Harper, T. G. Rials, N. Labbe´, T. Elder. 2007. High-energy electron beam processing of wood composites. ANTEC 2007, Cincinnati, OH.
D. P. Harper, T. Stortz, T. G. Rials, G. Dorsey, W. L. Griffith, K. R. Englund, M. P. Wolcott. 2007. Electron-beam curable additives for wood-plastic composites. Proceedings of the Ninth International Conference on Woodfiber-Plastic Composites. Madison, WI.
D. P. Harper, W. L. Griffith, T. G. Rials, G. Dorsey. 2006. Electron-beam processing of wood-polyethylene-acrylic composites. SAMPE, Long Beach, CA.
W. L. Griffith, G. F. Dorsey, D. P. Harper, W. W. Moschler, T. G. Rials, P. M. Winstorfer, et al. 2006. Electron-beam cured resin systems for wood composites. ANTEC 2006, Charlotte, NC.
D. P. Harper, Lee, S.-H., and Dadmun, M. 2006. Interactions between PS-PMMA based block copolymers and wood derivatives. Paper presented at the 2006 AIChE Annual Meeting, San Francisco, CA.
M. Gaugler, W. J. Grigsby, D. P. Harper, and T. G. Rials. 2006. Chemical imaging of PRF and tannin-based wood adhesive systems. 8th Pacific Rim Biobased Composites Symposium.
D. P. Harper and M. P. Wolcott. 2005. Chemical imaging of wood-polypropylene composites. Proceedings of the Eighth International Conference on Woodfiber-Plastic Composites. Madison, WI. pp. 153-160.
D. P. Harper, M.-P. Laborie, and M. P. Wolcott. 2004. Lubricant, Copolymer, and Homopolymer Interactions and their Impact of Mechanical Properties, 32nd Annual Conference on Thermal Analysis and Applications, Williamsburg, VA.
D. P. Harper, M.-P. Laborie, and M. P. Wolcott. 2004. Molecular Relaxations in Wood-Polypropylene Composites, 32nd Annual Conference on Thermal Analysis and Applications, Williamsburg, VA.
D. P. Harper, J. F. Hunt, and K. Friedrich. 2004. Three-dimensional Engineered Fiberboard: Opportunities for the Use of Low Valued Timber and Recycled Material, The 38th International Wood Composites Symposium. Pullman, WA.