聚乙烯醇缩丁醛/镀镍石墨复合材料薄膜的电磁屏蔽性能及机理  

Electromagnetic Shielding Performance and Mechanism of Polyvinyl Butyral/Ni-Graphite Composite Films

作　　者：王雪娇 杨向璟 温变英[1] Xuejiao Wang;Xiangjing Yang;Bianying Wen(School of Material Science and Mechanical Engineering,Beijing Technology and Business University,Beijing 100048,China)

机构地区：[1]北京工商大学材料与机械工程学院

出　　处：《高分子材料科学与工程》2019年第5期51-56,共6页Polymer Materials Science & Engineering

基　　金：国家自然科学基金面上项目(21274007);北京工商大学高分子功能薄膜创新团队(19008001071)

摘　　要：采用溶液流延法制备了聚乙烯醇缩丁醛/镀镍石墨复合材料薄膜,重点考察了填料含量对其电磁屏蔽效能的影响,通过复介电常数、复磁导率的变化对其电磁屏蔽机理进行了探讨,并计算了不同填料含量时复合材料的电磁屏蔽效能理论值。实验结果表明,随着镀镍石墨含量增加,复合材料的电磁屏蔽效能升高,当填料体积分数(φ)达20%时,其的电磁屏蔽效能可达45.5 dB(10 GHz)。复合材料的电磁屏蔽机理以电损耗为主。将电磁屏蔽效能的理论值与实测值对比发现,当填料含量较低时,实测值小于理论值,随着填料含量的增加,填料在基体中构成较完整的导电网络,两者之间的差距随着填料含量的增加逐渐缩小,当填料体积分数达20%时,实测值与理论值趋于一致。The polyvinyl butyral(PVB)/nickel-coated graphite(Ni-graphite)composite films for electromagnetic shielding were prepared via solution casting method.The effects of filler contents on the electromagnetic shielding effectiveness(SE)of the composite films were studied,and the corresponding electromagnetic shielding mechanism was discussed.The SE value of the composites was calculated according to the electromagnetic shielding theory.The results show that the SE of the composite films rises up with the increase of nickel-coated graphite content.When the Ni-graphite volume fraction reaches 20%in composites,the film obtains a high SE of 45.5 dB at the frequency of 10 GHz.Experimental facts indicate dielectric loss is the main form of the dissipation of energy in the electromagnetic shielding mechanism.By compared the theoretical calculated and experimental SE value,it is found that the experimental SE value is lower than the theoretical calculated value.However,the gap between these two group values becomes small with the increase of the filler content due to a well-constructed conductive network.Especially,the theoretical calculated and experimental value is closing to each other when the Ni-graphite volume fraction reaches 20%in composites.

关 键 词：聚乙烯醇缩丁醛 镀镍石墨 电磁屏蔽 复合材料 

分 类 号：TQ324.3[化学工程—合成树脂塑料工业]