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Types and research progress of PVA-based hygroscopic films

Views: 56     Author: Site Editor     Publish Time: 2022-11-07      Origin: Site

The PVA-based hygroscopic film is prepared by blending high-polymer PVA with other polymers or inorganic substances by a certain film production process. Polymer blend films can improve or modify the physicochemical properties of one or all of the components. An important physicochemical property of the blend is the compatibility of the polymer components, as this can affect the mechanical properties, morphology, permeability, and degradability of the film. Much research has been done on the compatibility of various polymer components, the most common being the compatibility of biopolymers with synthetic polymers, and such blends can be used as biochemical and degradable materials.

Here is the content list:

l Research Status of PVA and Starch Composite Films

l Research status of PVA and chitosan composite films

l Research status of PVA and cellulose composite films

l Research status of composite membranes prepared by blending PVA and inorganic substances

PVAsep


Research Status of PVA and Starch Composite Films

Starch polymers are natural biopolymers with readily available and biodegradable properties. Starch is present in carbohydrate vegetation such as corn, wheat, potatoes, etc. Starch is often used in the production of edible films, but it has poor moisture barrier properties and weak mechanical properties. To improve the performance of starch-based films, starch is often blended with other biodegradable polymers or synthetic polymers such as polylactic acid and polyvinyl alcohol to make films. This composite film is mainly used for degradation materials at home and abroad. At present, the research on PVA/starch composite films has been very specific, involving the research fields of mechanical properties and thermal properties of composite films. The mechanical properties and crystallization behavior of PVA/starch films were studied, and the results showed that the increase in starch content decreased the mechanical properties of the composite films, and could affect the crystallization temperature and melting temperature of the films to shift to the lower temperature. The hemocompatibility of starch/PVA films was investigated and it was observed that the addition of starch improved the hemocompatibility of polyvinyl alcohol films and increased clotting time. PVA/starch film can also be used in agricultural production, such as mulch material. Mulch material not only prevents diseases and insect pests, increases nighttime thermal insulation, and anti-aging, and increases soil aeration, but also can be absorbed by plants as fertilizer after starch degradation.


Research status of PVA and chitosan composite films

Chitosan is a biocompatible, antibacterial, and nontoxic polymer polysaccharide. The non-toxicity and antibacterial properties of chitosan have important application value in the preservation of fruits, vegetables, and food. However, chitosan is insoluble in water and general organic solvents, which limits its scope of application. Therefore, increasing the water solubility of chitosan can improve the use-value of chitosan in the preservation of fruits, vegetables, and food. Chitosan/PVA blend films were prepared using formaldehyde as a cross-linking agent, and it was found that the water content and water vapor transmission rate of the composite films increased with the increase of chitosan content, and the films still had antibacterial properties. The biochemical properties and bioactivities of chitosan/PVA film used for strawberry packaging were studied, and the results showed that the two had molecular compatibility; strawberry preservation experiments proved that the composite film extended the shelf life of strawberries.


Research status of PVA and cellulose composite films

Cellulose is a ubiquitous water-insoluble and water-swelling natural carbohydrate. The hydroxyl groups on the glucose unit of cellulose form strong hydrogen bonds due to their crystallinity, which makes cellulose hard and insoluble in most solvents. To reduce or dissolve crystalline cellulose, hydrophobic groups such as methyl or hydroxypropyl are introduced into the cellulose chain. Methylcellulose (MC) is the most common modified cellulose, which is chemically cross-linked with dialdehydes under the action of a strong acid to form hydrogels. Currently, the chemically cross-linked structures of MC hydrogels are rarely reported. Existing studies have reported the compatibility of PVA with MC hydrogels. PVA and MC have good compatibility in aqueous solutions but are only partially compatible in the solid-state. PVA is a soft and elastic material, but MC is prone to brittleness and cracking. The study found that MC and PVA are only partially compatible at medium and low concentrations, while in high concentration MC solutions, the two show better compatibility.


Research status of composite membranes prepared by blending PVA and inorganic substances

Introducing inorganic substances into polyvinyl alcohol can not only make the composite film have the physical and chemical properties of inorganic materials but also solve the problem of poor water resistance of the composite film. Inorganic materials include nanomaterials (such as silica), calcium chloride, ferric tetroxide, and sodium alginate. Nanomaterials have certain surface effects and small size effects. The surface effect can promote the strong adsorption of PVA on the silica surface; the small molecule effect makes it form a dense network structure with the PVA macromolecules. The hydroxyl groups on the PVA molecule can react with inorganic substances. This reaction destroys the intra- and inter-chain hydrogen bonds of PVA molecules and reduces the crystallinity of PVA.


The above is about the types and research progress of PVA-based hygroscopic film. If you are interested in PVA 1599, PVA 0599, PVA2488, PVA2688, PVA1799, Polyvinyl Alcohol Powder, you can contact us and we will give you a detailed introduction, our website is https://www.eastchem.com.cn/. I look forward to your arrival very much and hope to cooperate with you.


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