A kind of melt processable polyvinyl alcohol composition and preparation method

Abstract

The invention relates to a polyvinyl alcohol composition capable of being subjected to melt processing. The polyvinyl alcohol composition comprises polyvinyl alcohol and a phosphoric acid ester compound according to a weight ratio of 70-99:30-1, wherein the polymerization degree of the polyvinyl alcohol is 500-2400, and the alcoholysis degree of the polyvinyl alcohol is 85-100%. The preparation method comprises: pre-mixing polyvinyl alcohol and a phosphoric acid ester compound, adding the mixed material to an extruder, extruding, and granulating the extruded material to prepare the thermoplastic polyvinyl alcohol composition. Another preparation method comprises: placing polyvinyl alcohol into distilled water to prepare a uniform solution, weighing and adding the uniform solution to a phosphoric acid ester compound polyvinyl alcohol solution according to a required part ratio, uniformly stirring and mixing, drying, placing the dried mixture into an extruder, and directly extruding and granulating to prepare the thermoplastic polyvinyl alcohol composition. The prepared polyvinyl alcohol composition of the present invention can be used for preparing fiber products, film products, hollow containers, and pipes.

Description

Technical field [0001] The invention belongs to the field of chemical products, and particularly relates to a melt-processable polyvinyl alcohol composition and a preparation method thereof. Background technique [0002] Polyvinyl alcohol (PVA) is a water-soluble polymer that can be produced on a large scale by non-petroleum routes. The large number of hydroxyl groups in the polyvinyl alcohol molecule makes it have excellent oil resistance, solvent resistance and gas barrier properties, and has unique advantages in packaging and transportation of food, drugs, pesticides, and hydrocarbon reagents. However, because PVA polymer chains are prone to form a large number of intramolecular and intermolecular hydrogen bonds between adjacent hydroxyl groups, their thermal decomposition temperature (200-250°C) is close to the melting point (220-240°C), and thermal decomposition occurs during melting. Therefore, it is difficult to melt processing, and solution spinning and cast film forming...

AI Technical Summary

Problems solved by technology

For example, Japanese patent JP77110782 reports a method for forming a film of melt-blown polyvinyl alcohol using water as a plasticizer, but the thermal stability of water as a plasticizer is poor, and bubbles are likely to be generated during the process, resulting in the film being unable to be uniformly formed.

Chinese patent CN1368515A discloses a new speed-increasing method for thermoplastic processing of polyvinyl alcohol film. This method mainly selects a polymerizable amide monomer as a plasticizer, and controls more water in the resin to combine The form of water exists, thereby effectively reducing the processing temperature of PVA resin, but the plasticizer selected by this method is easy to migrate and has certain toxicity, so the prepared film is not suitable for food packaging film

Its composite plasticizer is a compound of glycerin, polyethylene glycol and dimethyl sulfoxide. The preparation process of this modified material is complicated and its application range is narrow. It is mainly used in the production of films.

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