Analysis of Release Characteristics and Composition of VOCs from Oriented Strand Board with Isocyanate Adhesive

To understand the release of VOCs from oriented strand board with isocyanate adhesive, amount of VOCs released from oriented strand board with isocyanate adhesive was tested by 1 m³ climate chamber method under a cycle of 28 days. the regression equation of VOCs emission with testing time was established by using nonlinear regression analysis method. Meanwhile, the similarities and differences of VOCs composition between oriented strand board with isocyanate and other kinds of wood-based panels were compared and analyzed. The results showed that the release of VOCs from oriented strand board with isocyanate adhesive decreased with the increase of testing time, and the release of VOCs decreased rapidly from the first day to the seventh day of the test, which is the rapid release period. The VOCs emission decreases rapidly from the eighth day to the fourteenth day, which is the rapid release period. The release of VOCs decreases smoothly from the fifteenth day to the twenty-eighth day, which is the release equilibrium period. The non-linear regression equation of VOCs emission from oriented strand board with isocyanate is y=a−b × ln(x + c), and the correlation R² of the regression equation is more than 0.98. The proportion of composition in VOCs from oriented strand board with isocyanate adhesive ranking from the highest to the lowest as following: aromatic hydrocarbons, olefins, esters, alkanes, aldehydes and ketones, alcohols, and others. Wood-based panels VOCs of aromatic hydrocarbons accounted for the largest proportion, about 4–8 times more than the solid wood products. Solid wood products VOCs of aldehydes and ketones accounted for the largest proportion, about 3–28 times more than the wood-based panels. The proportion of aromatic hydrocarbons in VOCs of oriented strand board with isocyanate adhesive is lower than that of wood-based panels with urea-formaldehyde, which is about 17%–28% of wood-based panels with urea-formaldehyde. The percentage of alkanes in VOCs of oriented strand board with isocyanate adhesive is lower than that of wood-based panels with urea-formaldehyde, which is about 7%–18% of wood-based panels with urea-formaldehyde. The main aromatic hydrocarbon monomer of VOCs from oriented strand board with isocyanate adhesive is p-dichlorobenzene, while the main aromatic hydrocarbon monomer of VOCs from wood-based panels with urea-formaldehyde is p-xylene.