Analysis of bonding mechanism of glass fiber-reinforced bamboo plywood

Bamboo curtains, coarse glass fiber cloth, bamboo mat, poplar veneer, and fine glass fiber cloth impregnated with phenolic resin adhesive were sequentially laid from the inside to the outside, and the symmetrically balanced material was sent to the hot press. The bonding mechanism of the resulting glass fiber-reinforced bamboo plywood (GFRBP) was analyzed using environmental scanning electron microscopy (ESEM) and Fourier transform infrared (FTIR) spectroscopy. The bonding between the phenolic resin and fiberglass cloth was achieved with a coupling agent, which reacted chemically with both the fiberglass cloth and phenolic resin. ESEM showed that glass fiber was bonded strongly with phenolic resin after treatment with coupling agents such as KH-550, KH-560, and KH-792. When the GFRBP was damaged, there was no breakage at the bonding surface between the glass fiber and phenolic resin. During the hot-pressing process, the phenolic resin easily migrated to the middle of the gap between plywood plates, which promoted better integration and properties. FTIR results showed that the longitudinal sides of the GFRBP pressed by the fiberglass cloth that had been treated by the coupling agents KH-550 and KH-792 were similar to each other, but those treated with KH-792 contained more -CH2- and had a longer carbon backbone.