Poly(propylene carbonate)/clay nanocomposites with enhanced mechanical property, thermal stability and oxygen barrier property

Abstract To develop eco-polymeric materials is of significant importance to protect the global environment and promote the sustainable development of human society. Poly (propylene carbonate) (PPC) as a new biodegradable polymer has attracted much interest, but some properties of PPC have to be improved before the practical utilization. In this work, the re-dispersible unmodified laponite and montmorillonite (MMT) were used as the nanometer reinforcing phase to enhance the mechanical property, thermal stability and oxygen barrier property of PPC. Via a simple solution mixing method, the PPC/laponite and PPC/MMT nanocomposites were fabricated. The unmodified laponite and MMT were well dispersed in the PPC matrix, which was confirmed by TEM results. As a result, the obtained PPC/clay nanocomposites exhibited high transparency (>80%) and enhanced storage modulus (100–150% higher than PPC), when the clay content was in a range of 1–10 wt%. In addition, the incorporation of lower than 3 wt% of laponite and MMT increased the elongation at break and thermal stability of PPC. The initial decomposition temperature (Td10%) of PPC/clay nanocomposites with 1 wt% clay was approximately 250 °C, which was substantially higher than that of pure PPC (215 °C). The PPC/clay nanocomposites with 7 wt% clay displayed the lowest O2 permeability, which was two orders of magnitude lower than that of pure PPC. Therefore, the resultant PPC/clay nanocomposites with enhanced properties have a potential to boost the practical utilization of PPC.