无机粒子改性EVA的粘接和流变性能研究

Study on Tackiness and Rheology of Inorganic Particles Modified EVA

以乙烯-醋酸乙烯酯(EVA)为基体的热熔胶在地埋油气输送管道外防腐中有着广泛的应用,但常常由于其粘接强度及施工流动性的不足,导致管道外防腐失败。采用四氧化三铁、二氧化硅及三氧化二铝3种无机粒子对热熔胶进行改性,通过表征粒子粒径及分布、测试了其粘接性能、考察其流变性。结果显示,在实验范围内,加入四氧化三铁后,粘接性能呈逐步减缓的上升趋势;加入二氧化硅后,粘接性能呈先下降再上升再下降趋势;加入三氧化二铝后,粘接性能先提高再下降。当加入量较小时,会改善熔体的流变性,随着加入量的增大,熔体流变性开始变差。对于不同石蜡含量的热熔胶,石蜡对不同粒子改性的热熔胶增塑效果相近。

The EVA hot melt adhesives had been widely applied in sticking coating of pipe for oil and gas transportation. However, the coating appeared failure sometimes because of weaker tackiness and constructional flow properties of adhesives. Hot melt adhesives were respectively modified by ferroferric oxide, silica and aluminium oxide particles. Particles sizes and distribution was characterized. Adhesives performances and rheology behavior were measured. Results showed as follows： tackiness increased gradually after adding ferroferric oxide. However, adhesive tackiness decreased at first then increased when silica was added. Whereas tackiness trend of adhesive modified by aluminium oxide rose firstly and decreased afterward. Furthermore, rheology properties of adhesives were improved when particles content was low. But it would be bad when particles content was high. Finally, paraffin wax had similar plasticized effect to hot melt adhesives even modified by different particles.