Precautions for operation:
Provide good natural ventilation conditions. Operators must be specially trained and strictly abide by the operating procedures. It is recommended that the operator wear a self-priming filter dust mask, chemical safety glasses, gas-proof overalls and rubber gloves.
Stay away from kindling and heat sources, and smoking is strictly prohibited in the workplace. Use explosion-proof ventilation system and equipment. Avoid dust. Avoid contact with oxidants. When handling, handle with care to prevent the packaging and containers from being damaged.
Equipped with corresponding varieties and quantities of fire fighting equipment and leakage emergency treatment equipment. Empty containers may leave harmful substances behind.
Excellent properties of polyvinyl alcohol;
Soluble PVA is soluble in water, and the higher the water temperature, the greater the solubility, but it is almost insoluble in organic solvents. The solubility of PVA varies with alcoholysis degree and polymerization degree.
PVA with partial alcoholysis and low polymerization degree dissolves very quickly, while PVA with complete alcoholysis and high polymerization degree dissolves slowly. Generally speaking, the degree of alcoholysis is greater than the degree of polymerization, which affects the solubility of PVA. The dissolution process of PVA is staged, that is, affinity wetting-swelling-infinite swelling-dissolution.
Film-forming PVA is easy to form film and has excellent mechanical properties. The tensile strength of the film increases with the increase of polymerization degree and alcoholysis degree.
Adhesive PVA has good adhesion with hydrophilic cellulose. Generally speaking, the higher the degree of polymerization and alcoholysis, the stronger the adhesive strength.
When the heat-stable PVA powder is heated to about 100℃, its appearance changes gradually. Partially alcoholized PVA began to melt at about 190℃ and decomposed at 200℃. Fully alcoholized PVA began to melt at about 230℃ and decomposed at 240℃. Thermal cracking experiments show that the lower the degree of polymerization, the faster the weight loss; The higher the alcoholysis degree, the shorter the decomposition time.
Refer to the above content: Baidu Encyclopedia-Polyvinyl Alcohol