Preparation and properties of directionally reconstituted bamboo cellulose fiber/phenolic resin composites

Bamboo cellulose fiber was prepared via deligninfied treatment at different times, then was impregnated with phenolic resin, finally was fabricated into the directionally reconstituted bamboo cellulose fiber/phenolic resin composites (DBSP) under hot pressing. SEM, FTIR, and XRD tests indicate that with the increase of deligninfication time, the lignin content gradually decreases, the crystallinity of cellulose gradually increases, and the bamboo cell wall also becomes thinner, finally the bamboo cell wall is separated into micron-scale oriented bamboo cellulose fibers. Moreover, the performance tests display that the mechanical strength, water absorption and dimensional stability of DBSP are significantly improved with the increase of deligninfication time. Among them, DBSP (6 h) shows excellent comprehensive performance, in which the tensile strength and modulus of rapture are up to 254.3 MPa and 176.8 MPa, respectively; the water absorption of 24 h is decreased to 5.83%, and the absorbing water thickness and width expansion rate are 2.28% and 0.76%, respectively. Therefore, as a kind of high-performance bamboo orientation recombined composites, it could be widely used in wind tur-bine blades, automotive body and other fields.