| In recent years, with the improvement of living standards, building construction anddecoration, the requirement of building materials became economical, aesthetical andenvironmental. Although having great demand, due to the decreasing forest resources andthe shortcomings of wood production, the application of traditional wood production hadbeen restricted. Using plant straw, such as rape straw, instead of lumber, then, with plasticto made the new rapestraw-plastic decoration composite can make full use of abandonedbiomass resource, and avoid the environmental pollution caused by burning. This studyproved that, a certain physical and chemical processing carried on the rape straw stalkpowder, obviously improve the compatibility between rape straw powder and plastic, andenhance the processing and mechanical properties of the composite. This can provides areliable way for the comprehensive utilization of rape crops in Hubei province, enhancingproduct added value, and increasing the farmers' income.In the thesis, it has been reviewed that the research situation at home and abroad anddeveloping trend of wood-plastic composites (WPC), proposed to study and developrapestraw-plastic decorative composites. To the existing problems, an ideal to improve thecompatibility between rape straw powder and PVC with the combined method ofbasified-ammoniated and coupling agents. The idea is: with rape straw powder as mainmaterial, using the combined method of basified and ammoniated as pretreatment method,then using the method of coupling agents as hydrophobic modification method, withplasticization, crosslinking, enhancement reaction, we can crank out the rape strawbiomass composite by the process of compression molding or extrusion.The main contents and conclusions are as follows:1. There are 4 stage in the process of the thermolysis of rape straw: the first one is from 50℃to 100℃, which is the free Moisture Evaporation Inside the material; thesecond stage is from 100℃to 230℃, and the rape straw has slowly depolymerized; thethird stage, from 230℃to 710℃, is the thermolysis stage of cellulose, hemicellulose,and lignin; the last stage is from 710℃to 900℃, for the thermolysis and carbonized stageof the surplus lignin. The activation energy is 44.5KJ/mol,53.7KJ/mol,57.5 KJ/molunder different heating rate, which is in 230℃～380℃- the main temperature district ofthe thermal decomposition2. It was able to effectively remove the rape straw stalk moisture content dring 2hours under 105℃, its weight loss rate was controlled in 0.5％, which meets theindustrialization production requirements. The moisture regain rate of the 80M rapesstraw powder is the biggest, and it can reach 19.96％after 48h. So the dry rape strawpowder must be packed in waterproof plastic bag in 1h to prevent the moisture regain ofthe rape straw powder.3. Until 5 minutes' manipulation of heating below the temperature of 200℃, DEvalue of the rape straw powder increased sharply, therefore, the trend of chromaticitychange could can meet the requirements of product under the normal processing condition4. After the combined method of basified and ammoniated, the crystalline of the rapestraw would been obviously reduced, and the optimal reaction time is 24h.5. The best hydrophobic modification effectiveness was obtained for rape strawpowder with the double aminosilane coupling agents. We obtain the best modifiedcondition through the orthogonal experiment, the condition is: the dosage of doubleaminosilane coupling agents is 2.5％, modified time is 2h, modified temperature is 100℃,and mixing speed is 850r/min.6. The optimal size of rape straw powder is 80M; and the optimal filler level is 80phr;the optimal level of plasticizer -DOP is 7.5phr; the best flexibilizer is ACR-401, and theoptimal level is 12 phr; the optimal mass proportion of husk powder and rape strawpowder is 2:3; the optimal release agent is compound release agent include 50％liquidparaffin and 50％stearic acid, and the optimal level is 2 phr; the optimal level ofcrosslinking agent DCP is 1.8 phr.7. Twin-screw extruder is better than single screw extruder in the disperse and plastication behavior of plant fiber in PVC substrate.When filling amount of plant fiberhas a certain condition, the product property of pure PVC is better than recycled PVC.8. The regression equation describing the relation between bending strength andelastic modulus was obtained by using the three-factors quadratic regression orthogonalrotary method: Y=-1447.1923+17.8519Z1-9.3677Z2+33.6714Z3+0.1788Z1Z2-0.0609Z12-0.6722Z22-4.8102Z32, The optimal operating conditions were also discussed: The extrusiontemperature 169.55℃, screw speed 15.58r/min, melt pressure 3.5MPa. The optimalmechanical properties and hygienical guide line as follows: The bending strength is27.3Mpa, elastic modulus is 1747MPa, flexure experiment is 19mm,meet the industrystandard of BB/T0020-2001, surface anti-cigarettes-burned has no macular, crack, bubble,met the industry standard of GB/T15102-94 and formaldehyde content is 0 mg/100g,9. The water absorption of the rape-straw sheet is only 4.98％in 25℃, 48 hours,When the relative humidity of air is between 60～100, the most moisture absorption ofproduct is 4.75％, and it has a better adaptability to the environment.The results of the foundational research open up a reliable path for integratedutilization of abandon resources and agricultural industrialization, therefore, providepractical references for resolving "three-farming". Therefore, the research has aprominent economic, social and environmental benefit.
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