Preparation method of PVDC composition by VDC/MA copolymerization

Abstract

The invention provides a preparation method of a PVDC composition by VDC / MA copolymerization. The preparation method comprises the following steps: putting mixing monomer, chelating agent, dispersing agent, deionized water, pH regulator, thermostability plasticizing agent and composite initiating agent into a polymeric kettle, carrying out cold dispersion on the mixture for 30 minutes, starting polymerization when raising temperature fast to 65 DEG C at the agitator speed of 120rpm, then stirring at the speed of 8rpm / h to 20rpm / h and 3 DEG C / h to 5 DEG C / h and raising the temperature to 80 DEGC to 85 DEG C at the agitator speed of 170rpm to 180rpm, finally at the agitator speed of 170rpm to 180rpm, raising the temperature to 90 DEG C at the speed of 2.5 DEG C / h to 6 DEG C / h, reacting for1h to 2h at constant temperature, stopping polymerization, separating residual monomer in vacuum, reducing temperature, discharging materials, centrifugating, drying, adding post processing auxiliaryagent, raising the temperature to 80 DEG C at the speed of 25 DEG C / h to 30 DEG C / h, mixing, curing and obtaining the composition. The PVDC composition has good forming processing thermostability andcan be used for packing low-and-medium temperature food by multi-layer coextrusion film or coextrusion casting film.

Description

A kind of preparation method of VDC / MA copolymerized PVDC composition Technical field The invention relates to a method for preparing a PVDC composition, and more specifically, to a method for preparing a VDC / MA copolymerized PVDC composition. Background technique The main component of polyvinylidene chloride (PVDC) is vinylidene chloride (VDC). Due to its symmetrical molecular structure and the presence of hydrophobic chlorine, it has high crystallinity and melting point, water resistance, and The oxygen performance is good, and the gas barrier property is not affected by the environmental humidity, and it is widely used in food, medicine, military and other fields. The disadvantage is poor thermal stability. It is easy to decompose and remove hydrogen chloride at processing temperature to form olefin chains, causing discoloration of the product. At the same time, these olefin chains form many cross-linked network structures. This structure is insoluble in any solvent and is ...

AI Technical Summary

Problems solved by technology

These methods can improve the thermal stability and processability of resin to a certain extent; But all do not relate to adopting to change polymerization temperature and agitation speed to prepare the preparation method of the good VDC / MA copolymerized PVDC composition of processing thermal stability in polymerization process