A novel polymer/kaolinite nanocomposite based on polyurethane-imide (PUI) foams was prepared by in situ polymerization. The PUI foams were synthesized via the reaction between isocyanate terminated polyimide prepolymers and polyether polyol. The kaolinite was modified with an intercalating agent of potassium carbonate. XRD analyses of the intercalated kaolinite and the PUI/kaolinite nanocomposite foams indicate that both intercalated and exfoliated structures are formed. The cell structure, cell size distribution, thermal stability and mechanical properties of the PUI/kaolinite nanocomposite foams are characterized by SEM, TG and an electronic universal testing method. Kinetics of thermal degradation and thermal aging life of the nanocomposite foams are investigated and forecasted compared with those of the pure PUI foams. The results show that addition of the kaolinite significantly improves the heat resistance and mechanical properties. However, the functional groups of PUI foams don't change obviously. View Article Onlinekaolinite. It can be seen that the mean cell size of nanocomposite foams decreases rstly and then increases with increased contents of intercalated kaolinite. When the content of intercalated kaolinite is of 5 wt%, the mean cell size reaches the minimum value (0.70 mm). As the content further increasing to 7 wt% and 9 wt%, the mean cell sizes increase to Fig. 4 SEM micrographs and cell size distributions of PUI/kaolinite nanocomposite foams: (a) 1 wt% Kao-KAc, (b) 3 wt% Kao-KAc, (c) 5 wt% Kao-KAc, (d) 7 wt% Kao-KAc, (e) 9 wt% Kao-KAc. 53214 | RSC Adv., 2015, 5, 53211-53219 This journal is

Phthalonitrile resin/exfoliated hexagonal boron nitride ( h-BN) composites with high thermal conductivity were fabricated using a novel approach. The route included two steps, micro- h-BN was coated and dispersed by phthalonitrile monomers via the function of heterogeneous nucleation, and then micro- h-BN was exfoliated by heat release during the phthalonitrile curing process. The composites achieved a high thermal conductivity of 0.736W (m·K)−1 containing 20 wt% micro- h-BN, which is 3.17 times higher than that of pure phthalonitrile resin at 0.232W (m·K)−1. Compared to traditional routes, the novel preparation approach requires less BN fillers when improving the same thermal conductivity. Importantly, other thermosetting polymers can also encapsulate BN through this strategy, which paves a new way for preparing thermally conductive thermosetting polymer–matrix composites.

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