Highly transparent antibacterial polystyrene/styrene‐butadiene block copolymer/polyhexamethylene guanidine composite

The combination of transparency, antibacterial activity, and flexbility is of great importance for practical applications in industry. However, this remains a huge challenge to date. In this work, a ternary system of polystyrene (PS), styrene‐butadiene block copolymer (SBC), and polyhexamethylene guanidine (PHMG) is reported via a green melt blending method. Because of the excellent compatibility of the components, the elongation at break of the composite increased by 3.0%. The composite shows high optical transparency of 81.8% owing to the similar refractive index of PS, SBC, and PHMG. More importantly, the addition of 0.3 wt% PHMG endows the composite with splendid antibacterial property, which eliminates 99.9% of E. coli and restrains the formation of the biological membrane. The composite is expected to find promising applications in medical industry and electrical apparatus.