新型建筑节能墙体保温材料力学和热工性能研究

Study on mechanics and thermal performance of new building energy-saving wall insulation materials

以海藻酸钠和天然纤维为改性剂,制备了海藻酸钠天然纤维生物复合材料。利用万能试验机对材料的力学性能进行表征,通过电导仪分析了生物复合材料的热工性能,重点研究了木质纤维和稻杆纤维掺杂比例对生物复合材料综合性能的影响,评价了生物复合材料用于建筑节能墙体保温材料的可行性。结果表明,生物复合材料的抗弯强度、抗压强度及弹性模量均随木质纤维含量的增加而不断增大,当木质纤维的含量为100%时,试样的力学性能最优,抗弯强度和抗压强度分别达到0.573和1.410 MPa。样品中木质纤维和海藻酸钠粘结剂结合紧密,相互之间润湿性良好。生物复合材料的热传导率在0.078~0.089 W/(m·K)之间,即具有较好的隔热性能,可以作为建筑节能墙体的保温材料来使用。研究发现添加较高比例的木质纤维及适量的乙二醛交联剂可提高生物复合材料的传热能力和保温性能。

Alginate based lignocellulosic bio-composites were prepared with sodium alginate and natural fibers as modifiers. The mechanical properties of bio-composites were characterized by universal testing machine, and the thermal properties of bio-composites were analyzed by conductivity meter. Finally, the effects of the doping ratio of wood fiber and rice stem fiber on the comprehensive properties of bio-composites were studied, and the feasibility of bio-composites for building energy-saving wall insulation materials was evaluated. The results showed that the flexural strength, compressive strength and modulus of elasticity of bio-composites increased with the increase of wood fiber content. When the content of wood fiber was 100%, the mechanical properties of bio-composites were the best, with the flexural strength and compressive strength reaching 0.573 and 1.410 MPa, respectively. The lignocellulose and sodium alginate binder in the sample were closely bound and had good wettability to each other. The thermal conductivity of bio-composites ranged from 0.078-0.089 W/(m·K), which meant that they had good thermal insulation performance and could be used as thermal insulation materials for building energy-saving walls. It was found that adding a higher proportion of wood fibers and glyoxal crosslinking agent could improve the heat transfer and thermal insulation properties of bio-composites.