Influence of Degree of Polymerization of Cellulose and Hemicellulose on Strength Loss in Fire-Retardant-Treated Southern Pine

Summary Southern pine boards, both untreated and treated with a fire retardant, were exposed to either a room temperature or high temperature (66°C (150°F)) environment. Strength properties were measured after 1 and 1-1/2 years of exposure, respectively. The degree of polymerization and the chemical composition of α- cellulose isolated from the exposed wood were measured. Little relationship was found between degree of polymerization and strength. However, a strong relationship was found between the amount of mannan in the α-cellulose isolated from the wood and the modulus of rupture and the work-to-maximum load of solid wood. This correlation leads to the conclusion that hemicellulose plays an important role in determining the strength of wood.