Question

Which of the following major components of wood is primarily responsible for the tensile strength parallel to the grain?

Select one:

a. Lignin

b. Cellulose

c. Hemicellulose

d. Ash

e. Extractives

Answer 1

Sol: b. Cellulose

Tensile strength depends on wood density.for good tensile strength,load should be applied parallel to grains.

Cellulose offers resistance to tensile stress because of the covalent bonding within the pyranose ring and between the individual layers. layers. Hydrogen(H+ ion) bonds within the cellulose provide rigidity to the cellulose molecules by stress transfer and allow the molecule to absorb shock by subsequently breaking and deeforming. Hemi cellulose is another component in wood is also responsible for Strength criteria but in recent studies states that hydrolytic or enzymatic actions seems to be responsible for the earliest loss of Strength in wood.