Final Report: Fundamental Studies of Wood Interface Modification for Formaldehyde Pollution Avoidance and PreventionEPA Grant Number: R828565
Title: Fundamental Studies of Wood Interface Modification for Formaldehyde Pollution Avoidance and Prevention
Investigators: Meister, John J. , Choi, Gun Y.
Institution: Forest Products Research Center
EPA Project Officer: Hahn, Intaek
Project Period: September 15, 2000 through September 14, 2003
Project Amount: $324,254
RFA: Technology for a Sustainable Environment (1999) RFA Text | Recipients Lists
Research Category: Sustainability , Pollution Prevention/Sustainable Development
The objective of this research project was to determine if lignin copolymer-plastic blends can act as a binder in wood laminates or composites by conducting a fundamental study of thermoplastics that tacify the wood interface. These plastic binders would replace formaldehyde-based adhesives and would remove the source of the major domestic environmental exposure to formaldehyde.
Poly(lignin-g-[1-phenylethylene]) graft copolymer/poly(1-phenylethylene) is an effective plywood binder that is four times more durable, equal in tensile strength, and equal in compression strength to interior grade, urea-formaldehyde (methanal diamine-methanal) binders. Laboratory-made plywood bound with 18 percent and 24 percent lignin content copolymer, poly(1-phenylethylene) (styrene control: no copolymer layer) were tested by soak test, tensile test, and compression test with commercial Douglas fir and maple plywood.
In the soak/dry test, the laboratory-made plywood bound with 18 percent lignin content copolymer and commercial Douglas fir showed a low delamination rate. The average tensile energy decreased as the cycles of soak/dry exposure increased. The commercial Douglas fir bound with phenol-formaldehyde showed a tensile energy twice that of the three plywoods bound with other binders. The plywood bound with 18 percent lignin copolymer showed higher tensile energy than the 24 percent lignin copolymer binder. In compression testing, the copolymer-bound samples were stronger than interior grade urea-formaldehyde binder, commercial maple plywood, but weaker than phenol-formaldehyde binder, commercial Douglas fir plywood.
Tests were run on both sanded and unsanded plys formed into plywood at different pressures, temperatures, and durations for pressing. Samples made with sanded ply generally were weaker and less durable than plywood formed from sanded ply. Plywoods formed at different pressing durations and pressures had equal physical properties. Changing the temperature of the plywood formation process from 150ºC to 190ºC changed the failure mode of the plywood. Samples formed at 190°C tended to fail in the wood under tensile force, whereas those formed at 150°C tended to undergo tensile failure in the bond. These renewable material-produced and recycled plastic-based binders exceed the performance of urea-formaldehyde binders in industry standard performance tests.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
|Other project views:||All 27 publications||3 publications in selected types||All 2 journal articles|
||Adcock T, Shah V, Chen M-J, Meister JJ. Graft copolymers of lignin as hydrophobic agents for plastic (wood-filled) composites. Journal of Applied Polymer Science 2003;89(5):1266-1276.||
||Meister JJ. The modification of lignin. Journal of Macromolecular Science-Polymer Reviews 2002;C42(2):235-290.||