玻璃空心微珠保温材料的性能优化

发布时间：2018-05-06 21:13

  本文选题：玻璃空心微珠 + 无极保温材料　； 参考：《大连交通大学》2015年硕士论文

【摘要】：泡沫玻璃保温板相较于市场上广为流行的有机保温板来说,有着不燃、吸水率低等优点,但传统泡沫玻璃保温板制备工艺有着烧结温度高、气孔孔径不可控等缺点。本文采用玻璃空心微珠堆烧的方法制备泡沫玻璃保温材料,研究了玻璃空心微珠在形成保温板过程中的变化过程及不同烧结制度对玻璃空心微珠保温材料性能的影响,试图寻找烧结玻璃空心微珠保温材料的最佳烧结制度,并利用DTA、SEM、XRD、导热系数仪等检测手段对烧制好的玻璃空心微珠保温材料进行性能表征。其结果如下:玻璃空心微珠在达到软化温度时开始通过连接颈进行连结,随着烧结温度的提高,连接颈逐渐增大,直至分不出玻璃空心微珠之间的界限,在660℃烧结时形成一整块带有均匀气孔的玻璃空心微珠保温材料;之后烧结温度的提升造成气孔的合并、长大其容重逐渐降低。660℃至780℃之间的烧结温度烧结,样品的容重随着烧结温度的提升而降低,超过780℃烧结时,由于熔融态玻璃的粘度过低,造成玻璃空心微珠保温材料内的气体溢出加剧,容重有升高趋势;在700℃时开始出现析晶现象,随着烧结温度的提升,析晶现象加剧,同时析晶现象会造成物质的偏聚,对于孔壁较薄的样品来说,会显著提升样品的开孔率。在700℃烧结时,保温时间的延长会使气相物质在熔融态玻璃中充分的长大,降低样品的容重,在780℃时则对容重影响不大;但是长时间处于高温状态会造成玻璃成核量加大,导致样品中析晶的加剧;较低的容重意味着玻璃空心保温材料内气孔较多,或者气孔较大,可以显著降低玻璃空心微珠的导热系数;而开孔率的增加会使内部的气体流通加剧,造成导热系数的提升。提高烧结时的升温速率可以加大玻璃空心微珠保温材料内气相物质与熔融态玻璃的温差增大,气相物质的热胀冷缩的幅度也更大,可以降低玻璃空心微珠保温材料的容重,但降低幅度有限;同时由于并未给予玻璃充分的成核时间,并相对降低了玻璃达到成核温度的时间,对析晶量的影响较小。经实验确定,在烧结温度为780℃,升温速率为3℃/min,保温时间为0.5h的样品具有最佳的综合性能,其容重为0.131g/cm3,体积吸水率为6.955%,抗压强度为1.275MPa,同时测得该样品在25℃(实测23.06℃)的导热系数为0.602W/(m?K)。
[Abstract]:Compared with the organic thermal insulation board which is widely used in the market, the foamed glass insulation board has the advantages of noncombustible and low water absorption. However, the traditional preparation process of the foam glass insulation board has the disadvantages of high sintering temperature and uncontrollable pore diameter. In this paper, foam glass insulation materials were prepared by the method of glass hollow bead piling. The change process of glass hollow microbeads in the process of forming insulation board and the influence of different sintering systems on the properties of glass hollow microspheres were studied. This paper attempts to find out the best sintering system of the sintered glass hollow microbeads and to characterize the properties of the sintered glass hollow microbeads by means of DTAA SEM XRD and thermal conductivity meter. The results are as follows: when the glass hollow beads reach the softening temperature, they begin to connect through the connecting neck. With the increase of sintering temperature, the connecting neck increases gradually, until the boundary between the glass hollow beads can not be distinguished. When sintered at 660 鈩，

本文编号：1853888