Effect of adjustable molecular chain structure and pure silica zeolite nanoparticles on thermal, mechanical, dielectric, UV-shielding and hydrophobic properties of fluorinated copolyimide composites

• Published in: Applied surface science 2018-01, Vol.427, p.437-450
• Main Authors: Li, Qing, Liao, Guangfu, Zhang, Shulai, Pang, Long, Tong, Hao, Zhao, Wenzhe, Xu, Zushun
• Format: Article
• Language: English
• Subjects: Dielectric constant; Fluorinated copolyimide; Mechanical properties; Pure silica zeolite; Thermal properties; UV-shielding properties
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.08.024

•This work also provided a facile way to synthesize composite materials with adjustable performance.•The prepared PI/APSZN composite films have ultraviolet shielding property and exhibit improved thermal properties, which make the composite flims be used as ultraviolet shielding materials in outer space filled with high temperature and intensive ultraviolet light.•The prepared PI/APSZN composite films exhibit low dielectric constants, which can be applied to electronics. A series of polyimide (PI) films, polyimide/pure silica zeolite nanoparticles (PSZN) blend films and polyimide/amine-functionalized pure silica zeolite nanoparticles (APSZN) composite films were successfully prepared by random copolycondensation. Thereinto, PSZN were synthesized by hydrothermal method. The polyimides were derived from 4,4′-diaminodiphenyl ether (ODA), and three adjustable molar ratios (3:1, 1:1, 1:3) of 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl] propane dianhydride (BPADA) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA). The effects of PSZN, APSZN and different chain structure on PI films were specifically evaluated in terms of morphology, thermal, mechanical, dielectric and UV-shielding properties, etc. Comparison was given among pure PI flims, PI/PSZN blend films and PI/APSZN composite flims. The results showed that the thermal and mechanical properties of PI films were drastically impaired after adding PSZN. On the contrary, the strength, toughness and thermal stability were improved after adding APSZN. Moreover, the dielectric constants of the PI/APSZN composite flims were lowered but UV-shielding properties were enhanced. Interestingly, we found that the greatest effects were obtained through introducing APSZN in PI derived by the 1:1 ratio of BPADA:6FDA. The corresponding PI/APSZN composite flim exhibited the most reinforced and toughened properties, the largest decrement of dielectric constant and the best UV-shielding efficiency, which made the composite flim be used as ultraviolet shielding material in outer space filled with high temperature and intensive ultraviolet light. Meanwhile, this work also provided a facile way to synthesize composite materials with adjustable performance.