Properties of wood adhesives extended with sweet potato and cassava flours in kalumpit (Terminalia microcarpa Decne) plywood. Thesis (M.Sc.)

Se ensayo la harina de batata y de yuca como diluentes de los adhesivos de urea y fenolformaldehido. Se compararon las propiedades de los adhesivos con aquellos diluidos con harina de trigo, un diluente comunmente usado en adhesivas de resina sinteticas para reducir los costos de produccion de goma. Terminalia microcarpa, una especie poco conocida, se uso como substrato. Se empleo un diseno factorial de 3 x 5 completamente al azar con 5 repeticiones. Los factores fueron tipo de diluente y nivel de diluente. El tipo de diluente tuvo 3 niveles: harina de batata, de yuca y de trigo. El diluente tuvo 5 niveles: 10, 20, 30, 40 y 50 por ciento de resina solida adhesiva. El adhesivo de urea- formaldehido diluido con harina de batata desarrollo una buena calidad de pegante. La calidad, sin embargo, fue menor que la de los diluentes de harina de yuca y de trigo. La dilucion se puede hacer con 30 por ciento de harina de batata o 20 por ciento de HY con una disminucion relativamente pequena en la calidad del pegante. El adhesivo de fenol-formaldehido diluido con harina de batata produjo madera contrachapada con una buena calidad de adhesion. El valor fue mayor que el de la dilucion con HY y menor que la de harina de trigo. Los niveles propuestos para dilucion son 40 y 30 por ciento de harina de batata y yuca, resp. La madera contrachapada pegada con resina de urea fenolica cumple con los requisitos de las Especificaciones Estandar para Madera Contrachapada de PHILSA para tipos de adhesion interior y exterior. Muestras mas secas se quebraron al someterse a tension, especialmente aquellas pegadas con resinas fenolicas, las cuales utilizaron un tiempo de presion de mayor duracion. (RA-CIAT) spa

Sweet potato and CF were tried as extenders for urea and phenol formaldehyde adhesives. Properties of the adhesives were compared with those extended with wheat flour, a common extender in synthetic resin adhesives used to reduce its glueline costs. Kalumpit (Terminalia microcarpa), a lesser known species, was used as the substrate. A 3 x 5 factorial expt. in completely randomized design with 5 replicates was employed. The factors were type of extender and level of extender. The type of extender had 3 levels: sweet potato, cassava, and wheat flours. The extender had 5 levels namely 10, 20, 30, 40, and 50 percent of resin solid of neat adhesive. Urea formaldehyde adhesive extended with sweet potato flour developed good gluebond quality. The quality, however, was lower than that extended with either cassava or wheat flour. Extension can be done up to either 30 percent sweet potato or 20 percent CF by which a depression of gluebond quality will be relatively small. Phenol formaldehyde adhesive extended with sweet potato flour produced plywood with good bond quality. The value was higher than that extended with CF, and was lower than that extendedwith wheat flour. The proposed levels of extension are 40 percent and 30 percent for sweet potato and cassava flour, resp. Plywood glued with either urea or phenolic resin complied with the gluebond requirements of PHILSA Standard Specification for Plywood for interior and exterior types of bond. Most dry specimens were broken in tension, particularly those glued by phenolic resin, which used longer pressing time. (AS) eng