SOME PHYSICAL, MECHANICAL PROPERTIES AND TERMITE RESISTANCE OF AMMONIUM PENTABORATE-TREATED STRAND BOARD

摘要

In order to improve termite resistance and reduce formaldehyde emission level of strand board, ammonium pentaborate (APB) was introduced into strand board with phenol formaldehyde (PF) resin as its adhesive. The physical and mechanical properties, termite resistance and formaldehyde emission of panels were evaluated. The results showed that APB was very effective on improving the termite resistance even at low APB loadings. Its significant effect on reducing formaldehyde emission of strand boards wasalso obtained as expected, which can be explained by the reaction of ammonium and acetic acid with formaldehyde caused by APB during hot pressing. As same as the other borates such as disodium octaborate tetrahydrate (DOT) and zinc borate (ZB), APB alsoshowed a negative effect on physical and mechanical properties of strand board. The adverse effect could be compensated by a 3-layer structure which contained APB only in the surface layers of the strand board. Compared with DOT and ZB, APB showed the least influence in 3-layer strand board at same BAE level of 1.8%.