The manufacture of PVA membrane method
( 1) Through copolymerization modification, copolymerization or macromolecular reaction in the main chain or side of the base forces is introduced in the weaker units, less PVA molecules and molecular inter-atomic forces, in lower melting point; * * cola li company was synthesized for thermoplastic processing of pva, the pva of alpha containing carbon atom number less than 4 Olefin unit and/or vinyl ether unit, melting point is 160 - 230℃。
( 2) Blending modification, by joining with hydroxy generated hydrogen bond in PVA polymer of * * PVA molecular inter-atomic forces, lower melting point or raise the thermal decomposition temperature, such as sugar derivatives, collagen hydrolysate etc. Nishino Poly real sugar derivatives ( GEMA） And PVA blend, raise the thermal decomposition temperature, when the addition amount is to 25 wt %, the mixture of thermal decomposition temperature of 326 ℃.
( 3) Reaction after modification, based on the modification of hydroxy, PVA molecular chain can reduce the neat degree of PVA and improve the thermal stability of the unit structure, improve the performance of thermoplastic processing on the PVA.
( 4) Plasticizing modification, this method is simple, * *, more domestic and foreign research on plasticizing with water, inorganic salt, glycerin, polyol and its oligomers, caprolactam, alcohol amine (single or composite plasticizing modifier, reduce the melting point of PVA, improve processing flow.
the above is the simple introduction of PVA membrane several fabrication methods, hope the above content to your help, if you have related questions, welcome to inquire.