Manufacturing method of PVA film

u003cbru003e u003cpu003eMethod of manufacturing PVA filmu003c/pu003eu003cpu003eu003cbr/u003eu003c/pu003eu003cpu003e　　PVA film density is 1.26-1,29g/cm cubic, refractive index is 1.52, UV irradiation After the basket is white light. It has high water absorption and can be dissolved in water. The moisture content of the fiber can reach 30%-50%, and the moisture content can reach 4.5% under the environment of 65% RH and 25 ℃. u003c/pu003eu003cpu003e　　 (1) Copolymerization modification, introducing weaker units into the main chain or side groups through copolymerization or polymer reaction, weakening the intra- and intermolecular forces of PVA and lowering the melting point;** Kuraray has synthesized a thermoplastic processable pva, which contains α-olefin units and/or vinyl ether units with carbon atoms less than 4, and has a melting point of 160-230°C. u003c/pu003eu003cpu003e　　 (2) Blending modification, by adding a large number of polymers that can form hydrogen bonds with the hydroxyl group in PVA, ** the intermolecular force of PVA, lowering the melting point or increasing the thermal decomposition temperature, such as sugar derived Substances, collagen hydrolysates, etc. Nishino blends the sugar derivative Poly (GEMA) with PVA, and its thermal decomposition temperature is greatly increased. When the added amount is 25wt%, the thermal decomposition temperature of the mixture reaches 326°C. u003c/pu003eu003cpu003e　　(3) Post-reaction modification, by chemically modifying the hydroxyl groups on the PVA molecular chain, introducing structural units that can reduce the regularity of PVA and improve thermal stability, and improve the thermoplastic processing of PVA performance. u003c/pu003eu003cpu003e　　 (4) Plasticization modification, the method is simple and **, domestic and foreign researches on plasticization mostly use water, inorganic salts, glycerin, polyols and their oligomers, caprolactam, alcohol amines Such as single or compound plasticizing modifier, reduce the melting point of PVA and improve processing fluidity. u003c/pu003eu003cpu003e　　 The above is a brief introduction of several manufacturing methods of PVA film. I hope the above content will help you. If you have any related questions, please contact us. u003c/pu003eu003cpu003eu003cbr/u003eu003c/pu003e

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