Study On Synthesis And Application Of Benzoxazine As Wood Adhesive

A novel thermosetting polymer precursor is synthesized successfully in the organic solvent. Its composition and structure are characterized by FT-IR, 1H-NMR and the curing behavior of benzoxazine(BZ) is investigated using the differential scanning calorimetry (DSC). The results show that the composition of BZ is, to a large extent , depend on the polarity of the reaction medium, and the more polarity of solvent is, the less ring content is. It is also shown that because the free phenol structure in BZ can catalyze the curing reaction of BZ, the more the polarity of the solvent is, the lower both in the initial curing temperature and the energy curing are. MWNTs(multi-walled carbon nanotubes) is added into benzoxazine. The DSC and TGA show that it has more heat-resistant than before .So it is a good heat-resistant wood adhesive .Benzoxazine-based phenol resin has attracted a great deal of attention due to its volumetric changes upon the polymerization. The results show that the density of polymer is lower than its precursor under room temperature. However, the volumetric shrinkage has been found during isothermal cure .The higher the temperature is, the longer cure time is, the larger volumetric expansion will be. Also the asumption of reaction mechanism about BZ is given.Three adhesive(benzoxazine, benzoxazine compounded by MWNTs and common PF phenol) are applied to plywood, particlebard,we find that the former two wood adhesive have better properties. Because the new two adhesive have near properties, it is not good choice to add MWNTs, unless good heat-resistant is needed. Based on many experiments, this paper also demonstrate and filter the factors affecting the thickness swelling of particleboard after considered in care. And find the equation for thickness swelling of particleboard. The equation means that thickness swelling comes maily from the recovery of visco- elastical deformation of wood in particleboard, hygroscopical swelling of wood in particleboard and deformation caused by destroyed glue lines between particles. When the changes of moisture content in the board is rather great or obvious, the mechano-sorption creep item, shall add to the model. By tracking test on the different particleboard made of Populus ussuriensis, the results show that the thickness swelling equation are quite the same and coincide rather well with theoretical deduction...