Degradable Foam Tray Based on High-concentration Dispersed Cellulose Fibers Obtained by a Hot-press Baking Process

Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process.Bleached softwood pulp fibers with a concentration of 30%were dispersed at a high speed under the action of a dispersant.The effects of the dispersant dosage of the fibers on the porosity,foam density,and static compression characteristics were discussed.Furthermore,the effects of the reinforcing adhesive including polyvinyl alcohol(PVA),and cassava starch on the physical and mechanical properties of the foam trays were studied,as well as the relationship between these properties and the microstructure of the foam trays.The dispersant enhanced the rheological and blistering properties of the fiber dispersion.As the dispersant dosage increased from 2%to 4%,the foam density gradually increased and the compressive strain performance and residual compressive strain of the foam trays decreased.Under the condition of constant dosage of dispersant,increasing the fiber proportion from 67%to 77%improved the porosity and foam density and slightly reduced the static compression performance.In additioton,the static compression resistance of the foamed materials was improved by increasing the PVA dosage since PVA was beneficial for improving the strength of the foam trays.

A Novel Bio-Based Zirconium Phosphonate as a Flame Retardant and Smoke Suppressant for Epoxy Resin

Although epoxy resin has been widely used in various fields,it still suffers from some problems including brittleness and flammability.In this study,a new phosphonic acid,N,N-bis(phosphomethyl)glycine(GDMP),was prepared by Mannich reaction with bio-based glycine and then a novel layered zirconium phosphonate(ZrGDMP)was synthesized using GDMP and zirconyl chloride hydrate as reactants.The chemical structure of ZrGDMP was well characterized by 1 H and 31P NMR,SEM,XRD and XPS.The effect of ZrGDMP on the flame retardancy,smoke suppression,strengthening and toughening performances of the epoxy matrix was investigated and evaluated.TGA results indicated that compared with pure EP,ZrGDMP-EP composites showed higher char yield due to the catalytic charring effect of ZrGDMP.The pure EP exhibited high flammability,while ZrGDMP-EP composites possessed excellent thermal stability and remarkable fire resistance.The PHRR,THR,and TSP values of 3wt%ZrGDMP-EP were obviously declined by 39.6%,40.2%,and 24.9%compared to these of pure EP.Moreover,the tensile and impact tests implied that the addition of ZrGDMP can significantly reinforce the toughness as well as the strength of EP in terms of higher impact strength(24.8 kJ/m^(2))and tensile strength(57.7 MPa),which was mainly contributed to the uniform dispersion of ZrGDMP within the EP matrix.