摘要
通过六亚甲基二异氰酸酯型聚异氰酸酯(PHDI)分别与4,4'-二氨基二苯甲烷(MDA)和4,4'-二氨基二苯基醚(ODA)反应制备聚脲(PUA)气凝胶(MDA-PUA、ODA-PUA)。MDA-PUA气凝胶具有较低的线性收缩率和较高的孔隙率,压缩模量为11.4 MPa,导热系数为0.020 W/(m·K)。MDA-PUA气凝胶的初始分解温度为321℃,残炭率为19.3%。优选MDA-PUA气凝胶等体积取代砂制成复合砂浆。当气凝胶的掺杂体积分数高于30%时,砂浆可以达到轻质标准,导热系数可降低至0.097 W/(m·K),比纯砂浆低94.2%,气凝胶使轻质砂浆具有优异的保温性能。砂浆的抗折强度和抗压强度随着气凝胶用量的增加而降低,但轻质砂浆的28 d抗压强度仍可以满足轻骨料混凝土CL5−CL40级的使用要求。
Polyurea(PUA)aerogels were prepared by the reaction of polyhexamethylene diisocyanate(PHDI)with 4,4'-diaminodiphenyl methane(MDA)and 4,4'-diaminodiphenyl ether(ODA),respectively.MDA-PUA aerogel has lower linear shrinkage and higher porosity,with a compression modulus of 11.4 MPa and a thermal conductivity of 0.020 W/(m·K).The initial decomposition temperature of MDA-PUA aerogel is 321℃,and the carbon residue rate is 19.3%.MDA-PUA aerogel is preferred to replace sand in equal volume to make composite mortar.When the volume fraction of aerogel is higher than 30%,the mortar can reach the lightweight standard,and the thermal conductivity can be reduced to 0.097 W/(m·K),94.2%lower than that of pure mortar.Aerogel enables lightweight mortar to have excellent thermal insulation performance.The flexural strength and compressive strength of mortar decrease with the increase of the amount of aerogel,but the 28 d compressive strength of lightweight mortar can still meet the requirements of CL5−CL40 grade of lightweight aggregate concrete.
作者
罗玉梅
周昀
周易
邵雅菲
LUO Yu-Mei;ZHOU Yun;ZHOU Yi;SHAO Ya-Fei(School of New Energy and Materials,Southwest Petroleum University,Chengdu 610500,China)
出处
《应用化学》
北大核心
2025年第2期238-248,共11页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金(No.52073239)
四川省玄武岩纤维复合材料开发及应用工程技术研究中心开放基金(No.2022SCXWYXWFC010)资助。
关键词
聚脲气凝胶
轻质砂浆
导热系数
抗压强度
Polyurea aerogels
Lightweight mortar
Thermal conductivity
Compressive strength
