Polyvinyl alcohol borax

Han Jingquan, Lei Tingzhou, and Wu Qinglin. High-water-content mouldable polyvinyl alcohol-borax hydrogels reinforced by well-dispersed cellulose nanoparticles Dynamic rheological properties and hydrogel formation mechanism. Carbohyd Polym. 

Polyvinyl alcohol undergoes reactions typical of a compound with secondary hydroxy groups, such as esterification. It decomposes in strong acids, and softens or dissolves in weak acids and alkalis. It is incompatible at high concentration with inorganic salts, especially sulfates and phosphates precipitation of polyvinyl alcohol 5% w/v can be caused by phosphates. Gelling of polyvinyl alcohol solution may occur if borax is present. 

In this MiniLab, you will work with a polymer, polyvinyl alcohol. A polymer is a large molecule that consists of a chain of smaller repeating emits. By allowing polyvinyl alcohol to react with a borax solution, you will cross-link polymer molecules to form a gel not imlike the commercial green stuff you may have seen. You can then investigate some of the properties of the gel. 

Highly polymerized polysaccharides with adjacent OH-groups in cis position, or even 1,3-diols, such as in polyvinyl alcohol react with borax (77, 78, 55, 77). The reaction was studied by measuring the increase in viscosity of the respective polymer. For the molecular structure a cross linkage of the borate tetrahedron to the polysaccharides has been suggested (77) (Fig. 12). 

When mixed with borax, polyvinyl alcohol with a molar mass of about 100,000 g/mol turns into slime. ... 

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