A green nanocomposite membrane for concrete moisturizing, with excellent barrier properties and aging resistance

In order to solve the problems of moisture retention and environmental pollution in external curing of concrete, a polylactic acid (PLA)/titanium dioxide (TiO2) composite concrete curing membrane with ultraviolet aging resistance and hydrolytic degradation was prepared by melt blending method. It was found that TiO2 nano-particles as nucleating agent significantly improved the water vapor barrier properties of PLA by regulating the crystallinity and prolonging the tortuous path. Compared with pure PLA, the barrier properties of the composite membrane added with TiO2 is improved by 34.3%. In addition, the degradation weight loss percent of the composite membrane reaches 69.9% due to the hydrophilic hydroxyl groups on the surface of TiO2 nano-particles. The PLA/TiO2 composite membrane still maintains excellent mechanical properties and barrier properties after UV aging due to the UV shielding effect of TiO2.