| Protecting trees is an important part of human environmental protection.Compared with many other synthetic woods,polyurethane wood has the best overall performance,and it has the advantages of high rigid foam strength,strong bearing capacity,light weight,accurate product size,excellent repetitive performance,anti-moth,and easy processing.However,there are also problems such as high raw material costs and low mold casting productivity.In this paper,solid waste micro-powders such as sludge powder and fly ash were used as the main fillers.The formulation and preparation process of polyurethane wood were studied in depth and systematically.A polyurethane wood-like material with excellent mechanical properties was prepared.At the same time,the production cost was significantly reduced,and the application of a traditional polyurethane insulation board production line was discussed.Polyurethane wood-like boards meeting the requirements of office furniture screen panels were continuously prepared.Based on 100 parts by weight of polyether polyol and 200 parts of solid waste micropowder,the formulation of the high-filler system was studied:The ratio of NCO/OH was determined to be 1.05-1.15;The catalyst is stannous octoate and triethylenediamine,the content of which is 0.1-0.2 parts and 0.05-0.1 parts,respectively;Stabilizer is dimethyl silicone oil,the content of 2 parts;Chain extender is 1,4-butanediol,the content of 1-2 parts;Silane coupling agent for KH550,an amount of 6-8parts;The blowing agent is HCFC-141b,which can be adjusted within the range of 4-12 parts depending on the product density;The thickener is gas phase SiO2,the addition amount is 1-2 parts;The dispersant and leveling agent were BYK-161 and BYK-358,and the addition amounts were 1 parts and 1.5 parts,respectively.The study found that the maximum cell diameter of solid waste micro/polyurethane composites was reduced from1 mm to0.5 mm during the process when the material temperature rose from 20?to 60?.In the process of raising the ambient temperature from10?to 40?,the density of polyurethane products decreased from0.82g·cm-3to 0.65g·cm-3,while the range of 20?to 30?did not change significantly.Therefore,the material pore size and density can be adjusted by controlling the material temperature and mold temperature.The mold temperature is as low as 10?or so is more conducive to the formation of a smooth surface;The amount of feed once will affect the divergence of the reaction heat.In the preparation of polyurethane,we must choose different molds for the different products and optimize the amount of feed;In order to ensure the stable performance of polyurethane,when there is a large change in humidity,the formula or process must be adjusted according to different environmental humidity;Selecting the curing method of high temperature humidification with the temperature of 60-80?and the humidity of over 80parts can accelerate the maturation of the polyurethane products,and the final curing strength of the polyurethane products can be improved compared with the simple high temperature curing or the normal temperature curing.We have borrowed a plan to use low-cost skins to achieve demolding,and produced polyurethane sheets with cemented glass fiber mats and polyurethane fiberglass mats,which achieved multiple functions of demoulding,lowering costs,and enhancing the mechanical properties of the products.Finally,using a traditional polyurethane insulation board production line,polyurethane wood-like boards satisfying the requirements for office furniture screen panels were continuously prepared.The boards contained 150 parts of powder,a density of 200-300kg·m-3,and were covered with cement glass fiber mats.Verified the possibility of applying it to furniture plates. |
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