Study On The Preparation Of Micro/nano Fibrils And Its Improvement On Properties Of Poplar Plywood

China is lack of forestry resources. With rapid development of economy and enhancement of civilian living condition,the contradiction between need and supply has become prominent. Making full development of fast-grown forest is a efficient measure to deduce the contrary and a important form to resolve the shortage of wood sources. Our country is rich in poplar,which can be used as the raw material of wood-based panel. It can relieve the contrary between need and supply effectively.However,fast-grown poplar is soft and of low density, limiting the use scope of poplar plywood. Besides, although soybean glue has many advantages such as cheap, abundant, recyclable, facilitative, harmless and lasting, it can't reach the standard of GBⅡplywood as its bad waterproof capacity, low bonding strength and easy-to-be-decomposed character. As a result, the purpose of this paper is to improve the properties of poplar soybean adhesive plywood and UF resin plywood by micro/macro fibrils, making them available to more applications.In this paper,poplar pulp is processed to nano-fiber with ultrasonic crusher. Furthermore, the properties of morphology,molecular weight and crystal ratio were analyzed with electron microscope,granularity distributing machine and X-ray diffractor.FTIR,DSC,DMA is applied to analyze the influence of poplar macro/nano fibrils on soybean glue. The DMA figures of soybean glue illustrates that poplar macro/nano fibrils improve the elastic variety resistence of soybean glue.The curing reaction mechanism of UF and MF resin is analyzed to presume the influence of poplar macro/nano fibrils on UF and MF adhesive.To improve the adhesive strength of poplar plywood,add 1%-5% nano-fibre to soybean glue poplar plywood separately as reinforcement,and then spread glue on veneer on the amount of 480 g/m2. Hot press in the condition of 160℃,80 s/mm and 1.6 Mpa. It explicates soybean glue plywood with 3% nano-fibre addition performs highest adhesive strength,increasing by 56% in the strength than soybean glue plywood without nano-fibre. Add 1%-10% nano-fibre of spreading glue amount to urea-formaldehyde resin plywood to improve its adhesive properties. The parameter is as following:double-face spreading amount 280 g/m2,pressure 1.2Mpa,temperature 110 -120C,time 1-1.5min/mm. The adhesive strength raise with the increase of nano-fibre amount,and performs better.Add 1%-5% nano-fibre of spreading glue amount to MF adhesive,which is spread on the surface of plywood to improve the exterior performance of poplar plywood. Brushed MF with 3% and 5% nano-fibre,the color firmness of the veneer is improved prominently,20% higher than veneer brushed with blank MF. Adding nano-fiber can enhance surface abrading persistence distinctively,while 1% nano-fibre addition performs best.