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Preparation and properties of ternary polyimide/SiO 2 /polydiphenylsiloxane composite films
Author(s) -
Shang Zhenping,
Lü Changli,
Gao Lianxun
Publication year - 2006
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2078
Subject(s) - composite number , polyimide , materials science , ultimate tensile strength , thermal stability , ternary operation , dynamic mechanical analysis , composite material , glass transition , thermogravimetric analysis , sol gel , chemical engineering , polymer , nanotechnology , layer (electronics) , computer science , engineering , programming language
A series of novel ternary polyimide/SiO 2 /polydiphenylsiloxane (PI/SiO 2 /PDPhS) composite films were prepared through co‐hydrolysis and condensation between tetramethoxysilane, diphenyldimethoxysilane (DDS) and aminopropyltriethoxysilane‐terminated polyamic acid, using an in situ sol–gel method. The composite films exhibited good optical transparency up to 30 wt% of total content of DDS and SiO 2 . SEM analysis showed that the PDPhS and SiO 2 were well dispersed in the PI matrix without macroscopic separation of the composite films. TGA analysis indicated that the introduction of SiO 2 could improve the thermal stability of the composite films. Dynamic mechanical thermal analysis showed that the composite films with low DDS content (5 wt%) had a higher glass transition temperature ( T g ) than pure PI matrix. When the content of DDS was above 10 wt%, the T g of the composite decreased slightly due to the plasticizing effect of flexible PDPhS linkages on the rigid PI chains. The composite films with high SiO 2 content exhibited higher values of storage modulus. Tensile measurements also showed that the modulus and tensile strength of the composite films increased with increasing SiO 2 content, and the composite films still retained a high elongation at break due the introduction of DDS. The density and water absorption of the composite films were also characterized. Copyright © 2006 Society of Chemical Industry