Effects of DCP as a free radical producer and HPQM as a biocide on the mechanical properties and antibacterial performance of in situ compatibilized PBS/PLA blends

In situ compatibilized polybutylene succinate/polylactic acid (PBS/PLA) reactive blends were prepared by adding dicumyl peroxide (DCP) as a radical initiator at contents ranging from 0 to 0.5 pph via a melt blending process. HPQM (2-hydroxypropyl-3-piperazinyl-quinoline carboxylic acid methacrylate) was used as an antibacterial agent at varying dosages from 0 to 5000 ppm. The mechanical properties, physical properties and antibacterial performance against Escherichia coli of PBS/PLA blends were investigated. The results showed that the toughness of PLA increased with increasing PBS content, while the fracture behavior of PLA appeared to change from brittle to ductile. The addition of DCP was found to notably increase the elongation at break and tensile toughness of materials at the recommended loading of 0.2 pph; this optimal DCP loading corresponded to increases in the storage modulus and complex viscosity of PBS/PLA blends. DCP and HPQM addition did not affect the surface color of PBS/PLA blends. According to the antibacterial performance of HPQM against E. coli, the optimal dosages of HPQM loaded into PBS/PLA blends of 20/80 and 40/60 wt% with 0.2 pph of DCP were 2000 and 1500 ppm, respectively.