A series of polyimide(PI)films derived from pyromellitic dianhydride(PMDA)and 4,4'-oxydianiline(ODA)were prepared with the employment of chemical pre-imidization,and the pre-imidization degree(pre-ID)was found inf...A series of polyimide(PI)films derived from pyromellitic dianhydride(PMDA)and 4,4'-oxydianiline(ODA)were prepared with the employment of chemical pre-imidization,and the pre-imidization degree(pre-ID)was found influential on structures and properties of the films obtained.Specifically,a certain degree of chemical imidization could promote the in-plane orientation of molecular chains inside the film,which then enhanced the mechanical strength and reduced the coefficient of thermal expansion(CTE)of the films.Further,such pre-imidization process could expand the internal space gap inside the films,thereby lowering their dielectric constant and glass transition temperature.Our study provides a new approach for preparing high-performance PI films through chemical imidization.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(No.2017YFB0308103)the National Natural Science Foundation of China(No.51773007)the Fundamental Research Funds for the Central Universities(No.XK1802-2).
文摘A series of polyimide(PI)films derived from pyromellitic dianhydride(PMDA)and 4,4'-oxydianiline(ODA)were prepared with the employment of chemical pre-imidization,and the pre-imidization degree(pre-ID)was found influential on structures and properties of the films obtained.Specifically,a certain degree of chemical imidization could promote the in-plane orientation of molecular chains inside the film,which then enhanced the mechanical strength and reduced the coefficient of thermal expansion(CTE)of the films.Further,such pre-imidization process could expand the internal space gap inside the films,thereby lowering their dielectric constant and glass transition temperature.Our study provides a new approach for preparing high-performance PI films through chemical imidization.
