摘要
聚酰亚胺(PI)材料因其具有六元环分子结构和较高的含碳量,成为近年来制备石墨散热膜的热门前驱体。而镍作为过渡族金属元素,常被用做石墨烯催化生长基底,将镍元素掺杂在聚酰亚胺基底中可以有效提高其碳化和石墨化程度,改善其导热率。然而纯镍金属颗粒在PI前驱体聚酰胺酸(PAA)中会发生沉积导致难以分散均匀,通过在PI基体中添加可溶于有机溶剂的金属络合物乙酰丙酮镍(Ni(acac)2),制备了PI复合薄膜并在2700℃对其进行石墨化得到石墨膜。Ni(acac)2在高温下分解得到的镍,能够对聚酰亚胺的碳化起到促进作用,且可溶于有机溶剂也显著提高了镍在PI基体中的分散性,最终制备了表面平整的聚酰亚胺碳膜,其导热系数可达到782 W/(m·K),对比纯PI制备的碳膜其导热系数提升了30倍。分析了金属络合物Ni(acac)2催化聚酰亚胺碳化过程以及最终得到的碳膜结构,探究最终制备高导热石墨膜的可能性。
Polyimide(PI)material has become a hot precursor for the preparation of graphite cooling film in recent years because of its six-membered ring molecular structure and high carbon content.As a transition metal element,nickel is often used as the substrate for graphene catalytic growth.Doping nickel in the polyimide substrate can effectively improve its carbonization and graphitization degree and improve its thermal conductivity.However,pure nickel metal particles will deposit in the precursor of PI,polyamide acid(PAA),which makes it difficult to disperse uniformly.In this work,the PI composite film was prepared by adding a metal complex soluble in organic solvent,nickel acetylacetone(Ni(acac)2),into the PI matrix and graphitized at 2700℃to obtain a graphite film.The nickel obtained from the decomposition of Ni(acac)2 at high temperature can promote the carbonization of polyimide,and its solubility in organic solvent also significantly improves the dispersion of nickel in the PI matrix.Finally,the polyimide carbon film with a flat surface was prepared,and its thermal conductivity can reach 782 W/(m·K),which is 30 times higher than that of the carbon film prepared by pure PI.The purpose of this paper is to analyze the carbonization process of polyimide catalyzed by metal complex Ni(acac)2 and the final carbon film structure,and explore the possibility of finally preparing high thermal conductivity graphite film.
作者
罗旭良
吴嘉豪
刘靖
王子青
闵永刚
刘屹东
LUO Xuliang;WU Jiahao;LIU Jin;WANG Ziqing;MIN Yonggang;LIU Yidong(School of Materials and Energy,Guangdong University of Technology,Guangzhou 510000,China)
出处
《功能材料》
CAS
CSCD
北大核心
2023年第7期7145-7151,7179,共8页
Journal of Functional Materials
基金
国家自然科学基金项目(52003111,U20A20340)
国家重点研发计划项目(2020YFB0408100)
广东省重点领域研究发展计划(2020B010182001)。
关键词
聚酰亚胺
金属有机盐
催化
石墨化
导热
polyimide
organometallic salt
catalysis
graphitization
thermal conductivity
