A kind of water-soluble granulation method of modified polyvinyl alcohol

Abstract

The invention provides a water-soluble granulation method of modified polyvinyl alcohol, comprising the following steps: adding polyvinyl alcohol into water, heating and dissolving, adding plasticizer and hyperbranched aromatic polyamide polymer to the obtained solution in sequence And stir, after the solution cools down, add additives and seal, dry the obtained product for the first time, extrude and granulate, and then dry the obtained particles for the second time, the mass fraction of polyvinyl alcohol is 10~ 20%, the heating temperature is 80-100°C. In the water-soluble preparation method provided by the invention, each component is evenly distributed during the preparation process, and the prepared product has high transparency and good toughness, and the compounding of two plasticizers, trimethylolpropane and glycerin, produces a synergistic effect , so that the granulation is good, the surface of the product is refreshing and non-greasy, there are no harsh conditions in the preparation process, no high-temperature melting is required, the operation is simple, the safety is high, and it is easy to produce.

Description

technical field [0001] The invention belongs to the technical field of polymer material preparation, and in particular relates to a water-soluble granulation method of modified polyvinyl alcohol. Background technique [0002] Polyvinyl alcohol (PVA) is a water-soluble polymer with excellent comprehensive properties. PVA's oil resistance, solvent resistance and gas barrier performance are particularly outstanding, and it has unique advantages in organic solvent, food and drug packaging. Since the PVA polymer chain contains a large number of active hydroxyl groups, it is easy to form a large number of intramolecular and intermolecular hydrogen bonds, resulting in the melting temperature of PVA being quite close to its thermal decomposition temperature, and it is decomposed immediately after melting, so it is difficult to perform thermoplastic processing. PVA starts to change color when heated above 200°C, begins to decompose at 240-250°C, and will decompose violently at 300°C...

AI Technical Summary

Problems solved by technology

[0004] CN101864084A discloses a hydroxyethyl cellulose / polyvinyl alcohol blend film and a preparation method thereof. The invention uses a casting method to make a blend film, and then cross-links with phosphoric acid to obtain a film with good mechanical properties, thermal stability, and water resistance. Decomposition, anti-aging, while maintaining excellent biodegradable blend film, can be widely used in medicine, cosmetics, food packaging and other fields, however, the invention does not clearly explain the thermal stability of polyvinyl alcohol modified blend film

However, the ionic liquid used in this method is expensive, and the thermal stability of the film is not specifically disclosed

CN1786302A discloses a method for preparing high-performance polyvinyl alcohol fibers by melt spinning, which uses a composite modifier composed of nitrogen-containing compounds, hydrophilic auxiliary additives and water to carry out intermolecular hydrogen bond compounding with polyvinyl alcohol , to prepare modified polyvinyl alcohol, the invention realizes the melt spinning and high-stretching of polyvinyl alcohol through intermolecular hydrogen bonding, and prepares polyvinyl alcohol fibers with excellent mechanical properties from general-purpose polyvinyl alcohol without traditional wet Coagulation bath and other related complex processes in the spinning method of the method, the process is simple, economical, environmentally friendly, and easy to realize industrial production. However, although polyhydric alcohols and oligomers can slightly reduce the melting point of PVA in this method, it does not have a large extent. Widen the difference between melting point and decomposition temperature, the plasticizing effect is limited

[0005] To sum up, among the existing PVA modification methods, the modification method of copolymerization modification has higher requirements on equipment and technology, and it is impossible to modify ordinary PVA products that have been commercialized in large quantities. There are also some technical bottlenecks in the plasticizing method. The compatibility of the system has not been completely resolved during blending, and it is difficult to realize industrialization. The existing solution plasticizing method generally only reduces the melting temperature, and because ordinary plasticizers melt under high temperature melting conditions It is easy to vaporize under the environment, escape the modified system and pollute the production environment, which will have a negative impact on the material composition and processing flow

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