Modification of poly(propylene carbonate) with chain extender ADR-4368 to improve its thermal, barrier, and mechanical properties

Melt blending with the application of epoxy compound ADR-4368 as a chain extender was used to chemically modify polypropylene carbonate (PPC). 1H nuclear magnetic resonance spectroscopy (1H NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and tests using a universal material testing machine, a gas permeability tester, a water vapor permeability tester and other instruments were used to assess changes in the chemical structure, thermal and mechanical properties, and barrier efficacy of PPC before and after modification. The epoxy group in ADR-4368 reacted with the terminal hydroxyl group in PPC, considerably enhancing its mechanical properties, thermal stability and barrier efficacy to O2 and CO2. With the addition of 1% ADR-4368, the glass transition temperature of PPC was increased from 17 °C to 26.9 °C, while the thermal decomposition temperature (T−5%) of PPC was increased from 177.3 °C to 240.6 °C. Moreover, the tensile strength of the modified PPC was improved from 3.3 MPa to 20.7 MPa.