| Degradable wood plastic composite(WPC)can effectively avoid the environmental pollution problems of plastics while taking advantage of traditional WPC.Carrying out thermal insulation functional research on it,while complying with the requirements of China's sustainable development strategy,is of great significance for reducing the production cost of materials and broadening the application fields.In this study,polylactic acid(PLA)and salix wood powder were used as raw materials,and the degradable WPC was prepared by molding method.The mechanical properties,dynamic thermomechanical properties,and thermal properties of WPC with density,molding process,woodplastic ratio,coupling agent,and heat preservation agent And the influence of thermal insulation performance lays a research foundation for the preparation process and performance optimization of woodplastic thermal insulation composite materials.The research conclusion is as follows:1.When the design density is 1.0?1.2g/cm3 and the mixing temperature is 180?190?,as the density increases and the temperature increases,the mechanical properties of WPC show an upward and downward trend,respectively.The suitable density and mixing temperature are 1.2g/cm3 and 180?;taking hot pressing temperature(155?,170? and 185?),hot pressing pressure(4MPa,5MPa and 6MPa)and hot pressing time(4min,7min and 10min)as variables,using orthogonal test to study heat According to the influence of pressing process parameters on the mechanical properties of WPC,the best hot pressing process conditions were selected:temperature 185?,pressure 5MPa,time 7min.2.When the amount of wood flour added is 0?70%,the static bending strength and tensile strength of WPC show a downward trend,and the elastic modulus and impact strength show a trend of first increasing and then decreasing.The storage modulus,loss modulus,and Vicat softening Both the temperature and the heat deformation temperature showed an upward trend,and the thermal insulation performance and the total weight loss rate showed a downward trend;when the coupling agent KH550 was added in an amount of 0-5%,all the properties of WPC showed a trend of first increasing and then decreasing.The suitable dosage of KH550 is 50%and 1%.3.When the volume filling amount of the heat preservation agent is 0-25%,the density,various mechanical properties,storage modulus,loss modulus and total weight loss rate of the WPC modified by the heat preservation agent are in a downward trend.The trend is to increase first and then decrease,and the thermal insulation performance shows an upward trend.The insulating effect of hollow glass microspheres on thermal insulation performance is better than that of fly ash floating beads;the suitable volume filling amount of thermal insulation is 25%.4.When the amount of coupling agent KH550 used in the treatment of heat preservation agent is 0?5%,all the properties of WPC show a trend of first increasing and then decreasing.When KH550 is added with 1%,the properties of WPC modified with fly ash floating beads are relatively better.The static bending strength,elastic modulus,tensile strength and impact strength are 43.02MPa,5354MPa,28.35MPa and 2.88kJ/m2,respectively.Vicat softening temperature and thermal deformation temperature are 73.8? and 56.5?,respectively,and the thermal conductivity is 0.2312W/(m·K);when KH550 is added with 3%,the properties of hollow glass microsphere modified WPC are relatively better.The performance is 48.66MPa,4484MPa,26.73MPa and 2.73kJ/m2,Vicat softening temperature and heat distortion temperature are 70.9? and 56.8?,respectively,and the thermal conductivity is 0.2261W/(m·K). |
PDF Full Text Request