Remarkable enhancement in thermal performance of polypropylene carbonate by using exfoliated boron nitride nanosheets

Biodegradable polymers are expected to replace traditional petroleum-derived polymers to meet environmental needs. However, its poor heat resistance limits its wide use. Intensive efforts have been taken to enhance the heat resistance, but the results are less than satisfactory and involve complicated steps. In this work, a facile carboxymethylcellulose-boron nitride nanosheets (CMC-BNNS) are used to realize the heat resistance enhancement modification of biodegradable poly (propylene carbonate) (PPC). Sodium carboxymethylcellulose (CMC-Na) is used to exfoliate and functionalize hexagonal boron nitride (h-BN) for the first time. The obtained CMC-BNNS with a uniform size after differential centrifugation can be stably dispersed in water and organic solvents. Benefit from the surface multifunctional group and 2D splinting effect of CMC-BNNS, the resultant PPC/CMC-BNNS composites not only possess superior heat resistance, but also display better thermal conductivity and dynamic mechanical properties compared with PPC/BN composites. The glass transition temperature (Tg) of the of PPC/CMC-BNNS composites with 2.5 wt% CMC-BNNS loading content greatly increases to 39.19 °C from 27.39 °C of neat PPC. This work provides a novel route for exfoliating 2D materials and heat resistance modification of biodegradable polymers.