Preparation,Characterization And Processing Performance Of High Barrier Vinylidene Chloride-methyl Acrylate Copolymer

High barrier material has extraordinary barrier capability to oxygen,water vapor,carbon dioxide and other gases,which can greatly prolong the shelflife of goods when it is used as packaging material.Accordingly,there are extensive applications in various fields,such as food,medicine,tobacco,tea and et al.Polyvinylidene chloride（PVDC）is a significant one of high barrier materials.However,the melting temperature of PVDC is very close to the decomposition temperature,which makes PVDC very difficult to be processed.In this dissertation,methyl acrylate（MA）and vinylidene chloride（VDC）monomer were served to synthesize VDC-MA copolymer by suspension copolymerization.The VDC-MA copolymer resin with low melting temperature and porous morphology was prepared and the performance of VDC-MA copolymer resin was investigated,the main research contents are listed as following:Part one: the L₂₅（5⁶） orthogonal experiment was served to investigate the synthesis of VDC-MA copolymer,and the conditions of copolymerization were optimized.The structure of copolymer was characterized by FTIR and ¹H NMR respectively.Part two: According to the the L₂₅（5⁶） orthogonal experiment,VDC-MA copolymer was synthesized with different copolymerization conditions respetively to figure out the effects on the molecular weight,melting temperature,decomposition temperature,barrier capability and mechanical performance of copolymer.The VDC-MA copolymer with low melting point(148℃was prepared.The oxygen permeability and water vapor permeability reached 0.08⁰.12cm³/m²·0.1MPa·24h and 400⁶00g/m²·24h respectively.The VDC-MA copolymer resin with flocculent porous microstructure was prepared by choosing proper compound dispersants.The GMA was copolymerized with VDC-MA to improve the thermal stability,and the performance of VDC-MA-GMA copolymer was compared with VDC-MA copolymer.Part three: the prepared VDC-MA copolymer was blended with additives to investigate the effects on processability of VDC-MA.The films of copolymer were formed at 155℃ and 157℃ respectively,and the transmittance of the films were characterized.