Influence type of natural rubber on properties of green biodegradable thermoplastic natural rubber based on poly(butylene succinate)

Green biodegradable thermoplastic natural rubber (GB‐TPNR) based on simple blend of natural rubber (NR) and poly(butylene succinate) (PBS) was prepared using three NR alternatives: unmodified NR and epoxidized NR with 25‐ or 50‐mol% epoxide (ie, ENR‐25 or ENR‐50). It was found that ENR‐50/PBS blend showed the best compatibility, which resulted in superior mechanical and thermal properties with the highest crystallinity of the PBS phase, on comparing with the ENR‐25/PBS and NR/PBS blends. This might be attributed to stronger chemical interactions between the epoxide groups in ENR‐50 and the polar functional groups in PBS, which were confirmed by Fourier transform infrared (FTIR). Furthermore, scanning electron microscopy (SEM), atomic force microscopy (AFM), and polarizing optical microscopy (POM) micrographs of ENR‐50/PBS blend revealed phase separation with finer‐grained cocontinuous structure than in ENR‐25/PBS and NR/PBS simple blends. Furthermore, the chemical interactions in ENR‐50/PBS blend enhanced the resistance to accelerated weathering.