Phenolic Resin Modification Technology Of Poplar And Product Properties Research

With the rapid decrease of natural forest resources and the increasing attention to ecological and environmental protection, development and utilization of plantation wood has become a solution to the contradiction of current increasing timber demand and relative shortage of resource.In this study, artificial forest of Populus euramevicana cv. as the research object, low molecular weight phenolic resin as impregnating strengthening material, using the method of flat-pressure impregnation filling poplar. By response surface experiment and analysis, studies the technological factors on the poplar wood impregnation effect and the interaction effect between factors; the compression densification treatment for impregnated wood, make the physical and mechanical performance have been further enhanced. Through the microscopic analysis on the impregnated wood, explore and reveal the mechanism of modified fast-growing poplar. This study has important theoretical significance and practical value to enhance the physical and mechanical properties of plantation wood, improve low density plantation wood added value and expand the scope of use.Using wood compression and resilience characteristic absorb phenolic resin by the method of flat pressure impregnation. To analyze the effect of compression rate,, dwell time, dipping time, resin concentration on the impregnation effect of response surface analysis method, the results showed that:in the selected range, the MOR and MOE of specimen increased with the dwell time and dipping time, with the compression ratio and resin concentration increased first and then decreased, When the compression ratio was about 43%, dwell time was 20min, dipping time was 3h, resin concentration was about 27%, the maximum value of MOR was 84.5MPa, MOE was 8842MPa, respectively,increase of 49.5% and 49.3% compared with raw material, continue to increase the compression ratio and resin concentration, MOR and MOE decreased slightly; The hardness and weight gain rate increased with each factor, when the compression ratio was 50%, dwell time was 20min, dipping time was 3h, resin concentration was 35%, the maximum hardness was 30.79MPa, increase of 107.2%.Make compression and densification test of impregnated poplar by optimized process. The results show that:the impregnated poplar compression and densification had greatly improved its MOR and MOE, respectively, can be to reach 106.8MPa and 11057MPa, increase of 89.0% and 86.7% compared with raw material, but no significant increase in hardness.By FTIR and XRD analysis shows that small changes in poplar infrared spectra before and after impregnation, the degree of crystallinity is reduced, it shows that phenolic resin is mostly filled mechanically in the lumen and cell gap, a small portion had chemical reaction chemical reaction of wood components. By electron microscope photos can see the resin attached on the inner wall of the catheter and wood ray cell.According to production equipment conditions and product end-use and final performance requirements, suggest the flat-pressure impregnation process parameters is:the compression rate is 43%, dwell time was 20min, dipping time was 3h, the resin concentration is 27%; the impregnated poplar compression and densification process parameters is:compression ratio is 30%, resin concentration is 25% of, heating time is 0.5h.