No abstract

In the synthetic leather industry, solvent-free polyurethane film (SFPU) was poor in water vapor permeability (WVP) and washability. In this study, we introduced the hollow nano-TiO 2 spheres (HNTSs) with high photocatalytic performance and permeability performance as well as large surface area into the SFPU film to endued its superior water vapor permeability property, selfcleaning performance and water resistance. First of all, HNTSs were prepared via the controllable chemical route using HF for internal corrosion of solid nano-TiO 2 spheres, and then introduced into hydroxyl prepolymer to prepare solvent-free polyurethane/HNTSs composite film. The results of SEM, FT-IR and UV analyses indicated HNTSs were successfully dispersed evenly into SFPU. Application experiment results showed that the addition of HNTSs with hollow structure had an important effect on the WVP, photocatalytic performance, mechanical property, the water vapor transmission rate, self-cleaning performance as well as tensile strength were increased by 111.98%, more than 100%, and 36.368%, respectively.

Carboxyl polyhedral oligomeric silsesquioxane(P[POSS‐MAA]) modified layered double hydroxides (LDHs) (P[POSS‐MAA]‐LDHs) was prepared by exfoliating and recombination method, which used P(POSS‐MAA) and LDHs attracted each other through electrostatic force and hydrogen bond. The structure and morphology of P(POSS‐MAA)‐LDHs were characterized by X‐ray diffraction and transmission electron microscope, which showed that LDHs was exfoliated and P(POSS‐MAA) was on the surface of LDHs. Then it was introduced into the modified zanthoxylum bungeanum seed oil(MZBMSO) to obtain MZBMSO/P(POSS‐MAA)‐LDHs and applied it in leather fatliquoring process. The effect of the introduction of P(POSS‐MAA)‐LDHs on the flame retardancy, thermal stability, thermal insulation and smoke suppression of leather was investigated. Compared to the MZBMSO treated leather, the after flame time of MZBMSO/P(POSS‐MAA)‐LDHs treated leather decreased from 84 s to 32 s, and the limiting oxygen index increased from 23.1% to 27.5%, which exhibited improvement on flame retardancy of the leather. The temperature at 50% mass loss of MZBMSO/P(POSS‐MAA)‐LDHs treated leather increased from 375.1 to 408.3°C, which showed improvement on thermal stability of the leather. And the leather treated by MZBMSO/P(POSS‐MAA)‐LDHs had reduction of the total heat release and the total smoke production around 26.8% and 65.7%, respectively, which showed that MZBMSO/P(POSS‐MAA)‐LDHs treated leather had heat insulation and smoke suppression. Flame retardant mechanism of MZBMSO/(P(POSS‐MAA)‐LDHs) treated leather involved a combination of the gaseous phase and condensed phase flame retardancy. This work provided a new material for the flame retardant field and expanded the application range of polyhedral oligomeric silsesquioxane(POSS).