乙烯基三(2-甲氧基乙氧基)硅烷接枝乙烯-醋酸乙烯酯共聚物(EVA-g-VT2MES)的制备和表征

Preparation and Characterization of Vinyltri(2-methoxyethoxy)silane Grafted Ethylene Vinyl Acetate Copolymer

以乙烯-醋酸乙烯酯共聚物(EVA)为基体树脂的热熔胶粘接强度较低,这主要是因为EVA的内聚强度较低及胶合表面极性单元较少。为解决这一问题,以EVA为基体,通过熔融接枝法将极性乙烯基三(2-甲氧基乙氧基)硅烷(VT2MES)接枝到EVA主链上,得到乙烯基三(2-甲氧基乙氧基)硅烷接枝乙烯-醋酸乙烯酯共聚物(EVA-g-VT2MES)。借助傅里叶变换红外光谱仪(FT-IR)和核磁共振波谱仪(NMR)对产物的分子链结构进行了表征。结果表明,VT2MES可接枝到EVA分子链上,其接枝率最高可达2.37%。通过流变和熔融指数测试表明接枝产物的内聚强度得到了提高。将EVA和EVA-g-VT2MES制成胶膜黏合钢片,对比EVA,EVA-g-VT2MES的剥离强度最大可提升75.21%,表明了在EVA分子链上熔融接枝VT2MES可以大幅提高EVA基体的粘接强度。

The low hot melt adhesive strength of ethylene vinyl acetate(EVA)as a matrix resin is mainly due to its low cohesive strength and low polarity on the bonding surface.To address this issue,polar vinyltri(2-methoxyethoxy)silane(VT2MES)is grafted onto the EVA main chain through a melt grafting method,resulting in the synthesis of ethylene vinyl acetate grafted with vinyltri(2-methoxyethoxy)silane(EVA-g-VT2MES).The molecular chain structure of the product is characterized using Fourier transform infrared spectroscopy(FT-IR)and nuclear magnetic resonance spectroscopy(NMR),indicating that VT2MES hasbeen successfully grafted onto the EVA molecular chain,with the highest grafting rate of 2.37%.Rheology and melt index tests demonstrate an improvement in the cohesive strength of the grafted product.Adhesive films are prepared from EVA and EVA-g-VT2MES,and steel plates are bonded with them.Compared with EVA,the peel strength of EVA-g-VT2MES is increased by up to 75.21%,confirming that melt grafting of VT2MES onto the EVA molecular chain can significantly improve the adhesion strength of the EVA matrix.