In this study, the polyimide-polyvinylpolymethylsiloxane composite aerogel (PPCA) was synthesized by two different methods, stepwise chemical liquid deposition (SCLD) and direct chemical liquid deposition (DCLD). It is found that polyimide (PI) chains can only be introduced into the backbone of amine-modified polyvinylpolymethylsiloxane (PVPMS) by SCLD method. The introduced PI can further crosslink with PVPMS to form a PI-PVPMS cross-linked network structure, which makes the skeleton dense and endows the sample with high mechanical strength. For DCLD method, PI chains can only be coated on the surface of the sample rather than the whole skeleton, which leads to a loose internal structure. Furthermore, samples prepared by SCLD method possess higher initial thermal decomposition temperature compared with that by DCLD method.

在这项研究中，聚酰亚胺-聚乙烯基聚甲基硅氧烷复合气凝胶（PPCA）是通过两种不同的方法合成的：逐步化学液体沉积（SCLD）和直接化学液体沉积（DCLD）。发现聚酰亚胺（PI）链只能通过SCLD方法引入到胺改性的聚乙烯基聚甲基硅氧烷（PVPMS）的骨架中。引入的PI可以进一步与PVPMS交联以形成PI-PVPMS交联的网络结构，这使骨架致密并赋予样品高的机械强度。对于DCLD方法，PI链只能涂在样品表面上，而不能涂在整个骨架上，这会导致内部结构松散。此外，SCLD法制备的样品比DCLD法具有更高的初始热分解温度。