Modification of poly(butylene succinate) with biodegradable glycolic acid: Significantly improved hydrolysis rate retaining high toughness property

Marine microplastic pollution damages the marine biodiversity and endangers human health. Poly(butylene succinate) (PBS) is considered a biodegradable polyester; however, PBS has a slow degradation rate in seawater. In this research, glycolic acid (GA) segments were introduced in PBS main unit via melt polycondensation. The number-average weight of PBSGA copolymer ranged from 3.1 to 4.1 x 10(4) g mo1(-1) with GA contents of 0%-40%. PBSGA possessed excellent mechanical properties and thermal stability. The tensile strength was 6 similar to 40 MPa, the elongation at break was more than 220% and the thermal decomposition temperature was high than 380 degrees C. It was also found that the weight loss of PBSGA copolymer showed a tendency of alkaline > lipase > acidic > neutral > salt. In alkaline solution, the PBSGA copolymer completely decomposed after 21 days. In acidic and neutral solution, the increase of GA content improved the degradation rate of copolymer. In phosphate buffered solution, lipase accelerated the rate of ester bonds hydrolysis; however, salt had the opposite effect in NaCl solution. Thus, by introducing easily hydrolyzable GA groups, seawater degradable materials can be obtained to overcome the unfavorable factors of seawater environment.