Preparation method and application of hydrolysis-resistant PVA polymer

Abstract

The invention relates to a preparation method and application of a hydrolysis-resistant PVA (polyvinyl alcohol) polymer, which comprises the following steps: copolymerizing dodecyl vinyl ether, vinyl formate and vinyl acetate as monomers to prepare a PVA prepolymer, and performing alcoholysis on the PVA prepolymer to prepare the hydrolysis-resistant PVA polymer. The water content of the prepared hydrolysis-resistant PVA polymer is 0.5 to 1.5 weight percent; the prepared hydrolysis-resistant PVA polymer is applied to preparation of hydrolysis-resistant PVA fibers, firstly, the hydrolysis-resistant PVA polymer is added into a dissolving kettle containing DMF and water, the temperature is increased by stages until the hydrolysis-resistant PVA polymer is swelled, then CO2 gas is introduced into the dissolving kettle to form a certain pressure until the hydrolysis-resistant PVA polymer is completely dissolved, the CO2 gas is discharged within a certain time, a high-solid-content spinning solution with the solid content of 28-32 wt% is obtained, and then the hydrolysis-resistant PVA fiber is prepared from the high-solid-content spinning solution through dry-wet spinning; and the softening coefficient of the hydrolysis-resistant PVA fiber is 0.85 to 0.95. According to the method disclosed by the invention, the PVA polymer with good hydrolysis resistance is prepared, and the PVA fiber with good hydrolysis resistance is prepared from the PVA polymer.

Description

technical field [0001] The invention belongs to the technical field of polyvinyl alcohol polymers, and relates to a preparation method and application of a hydrolysis-resistant PVA polymer. Background technique [0002] Polyvinyl alcohol (PVA) polymer is composed of C, H, O three elements, the main chain is connected by C-C bonds, and the side group is a flexible chain polymer of hydroxyl (-OH). It is easy to form intermolecular or intramolecular hydrogen bonds, so that polyvinyl alcohol resin products have good adhesion and air tightness. In addition, PVA has a wide range of raw materials, low price, and is widely used in the preparation of fibers. However, since the side group -OH of PVA is a hydrophilic group, it is a water-soluble polymer, and it is also a synthetic material that can be completely degraded naturally. However, because the PVA structure contains a large number of hydrophilic groups (-OH), the external In the dry-wet change, it exhibits a strong affinity ...

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Problems solved by technology

Patent CN201110334528.9 adopts a blending modification method to modify PVA through sodium lauryl sulfate. Although the operation steps are simple, there is no chemical bond between sodium lauryl sulfate and PVA, and there is no Non-covalent bond, unable to cover all or part of the -OH in the PVA polymer, resulting in the unsustainable hydrolysis resistance of modified PVA

Chemical modification, such as chemical cross-linking, can form a chemically bonded cross-linked network between the polymer chains of PVA or convert the hydrophilic group -OH on the PVA side group into a water-resistant group, but in the existing PVA Polymer modification and grafting of water-resistant groups will increase the difficulty of operation. Because PVA polymers are easy to swell when exposed to water and common solvents, gel will be produced if the temperature is too high or the time is too long. Cross-linking effect is not ideal

In addition, too much cross-linking agent that forms chemical bonds with PVA polymers will affect the strength of PVA polymers in applications, while too low an amount to improve the hydrolysis resistance of PVA polymers is not obvious

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