Effects of fiber surface treatments on mechanical properties of wood fiber-cement composites

The purpose of this research was to determine the effects of treated and un treated hardwood, kraft softwood, and newsprint wood fibers on the 7- and 2 8-day bending strength, compressive strength, and toughness values for wood fiber-cement composites. Untreated and acrylicor alkylalkoxysilane-treated hardwood, kraft softwood, and newsprint wood fibers used in wood fiber-cem ent composites resulted in different bending and compression properties. Fi ber characteristics along with different chemical treatments influenced the composite properties. Compressive strength decreased for all fiber types a nd chemical treatments compared to the neat cement controls. Bending streng th values for all wood fiber composites were higher than the neat cement co ntrol specimens. Both the acrylic emulsion and alkylalkoxysilane treatments provided improvements in the bending strength values compared to the untre ated wood fiber-cement composites. Toughness improved for all untreated and treated wood fiber-cement composites compared to the neat cement control s pecimens. The toughness value results for the alkylalkoxysilane-treated fib ers were similar to the acrylic-treated fibers in that the longer kraft sof twood fiber-cement composites had the highest toughness values compared to the other fiber groups. (C) 2001 Elsevier Science Ltd. All rights reserved.