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The sodium lignin sulfonate was grafted into polyacrylamide hydrogel to synthesize polyacrylamide-lignin sulfonate hydrogel. The ammonium molybdate was introduced into the hydrogel network by immersion process to realize vision display. The absorbance, transparency, structure and morphology of sodium lignosulfonate-polyacrylamide hydrogel were measured by UV-Vis, FT-IR and SEM, respectively. The UV-Vis measurement results show that the hydrogel had the advantages of low cost, easy preparation, and excellent performance in quick response within 5 min. In addition, the photochromic and fading processes of hydrogels could be precisely controlled by UV light at different time and temperatures. FT-IR measurements showed that sodium lignosulfonate was successfully incorporated into the polyacrylamide hydrogel. SEM results show that the hydrogel exhibited a dense structure after complete drying, which made the hydrogel less susceptible to fading after photochromism. [ABSTRACT FROM AUTHOR]

By adding sodium lignosulfonate in the process of polyurethane foam foaming, and using aluminum hypophite (AHP) and expanded graphite (EG) as synergism flame retardants, the sodium lignosulfonate based polyurethane foam (PUF) with flame retardant properties were prepared by “one-step method”. Firstly, the flame retardation properties of the prepared synergism flame retardant PUF materials were characterized by using the limiting oxygen index (LOI) tester. Thermogravimetric analysis (TGA) and CONE calorimetry (CONE) were used to investigate the thermal stability and combustion behavior of flame-retardant PUF materials. Field emission scanning electron microscope (SEM) was used to analyze the microscopic photos of carbon residue after combustion. The analysis results show that when the SLS addition ratio is 4 wt% of the total mass of raw materials, the synergism ratio of AHP and EG is 1∶4, and the addition of the two synergism flame retardants is 30 wt%, the LOI value of biomass-based flame retardant PUF material increases to 31.6%. The addition of coefficent flame retardants improves the thermal stability and carbonization performance of PUF material. Thus, the flame retardant of the material is greatly enhanced. [ABSTRACT FROM AUTHOR]