Preparation and properties of polyimide nanocomposites with negative thermal expansion nanoparticle filler

Al2Mo3O12/polyethylene composites with reduced coefficient of thermal expansion

“…Sullivan and Lukehart [15] came to the same conclusion for the effect of 0.8 and 1.7 vol % loadings of nanometric and micronic ZrW 2 O 8 fillers in a polyimide matrix. Sharma et al [25] did not observe any additional effect of ZrW 2 O 8 nanofillers functionalized with 3-aminopropyltriethoxysilane or ZrW 2 O 8 fillers functionalized with 3-aminopropyltriethoxysilane/PI oligomer on reduction of the composite CTE for loadings between 5 and 15 vol % when compared Fig. 8 Maximum tensile and shear stresses in the PE matrix as a function of filler content.…”

“…They also observed that the variation of mean size of CaCO 3 nanoparticles may play a role in the CTE of CaCO 3 /PE composites, i.e., nanopowders with smaller mean particle size act more efficiently to decrease the CTE of a composite than do nanopowders with higher mean particle size. However, it is relevant to notice that Sharma et al [25] inferred that the CTE of ZrW 2 O 8 /polyimide composites was independent of the size of ZrW 2 O 8 filler. They showed that the 5 vol % loading of nanometric or micronic ZrW 2 O 8 fillers to polyimide (PI) matrix resulted in comparable CTE values.…”

“…For example, Sharma et al [25] reported a strong decrease of yield strain for 5-15 mass % additions inside PI matrix of ZrW 2 O 8 nanofillers functionalized with 3-aminopropyltriethoxysilane or with 3-aminopropyltriethoxysilane/PI oligomer. It should be noticed that even the addition of ductile Cu particles in a PE matrix [69] resulted in reduction of yield strain of Cu/PE composites.…”

“…However, in some cases, such as Al 2 TiO 5 , microstructural design and microcrack formation can be used to advantage to produce low thermal expansion materials with high thermal shock resistance [10]. On the other hand, the second approach makes use of the addition of thermomiotics, as the dispersed phase, in composites [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The most common role of thermomiotics in composites is to control the CTE of the matrix phase, which could be a metal, ceramic or polymer.…”

“…These tentative attempts generally focus on ZrW 2 O 8 , both as micronic and nanometric powders [11,[15][16][17][23][24][25]. This is understandable considering the isotropic physical properties of ZrW 2 O 8 and its strong negative CTE (* -9 9 10 -6 K -1 ) over a wide temperature range (0-1050 K), which includes the operational temperature range for polymer components.…”