To improve the properties of polyimide (PI), different mass fractions of alumina (Al2O3) nanoparticles, unmodified or modified by KH550, were incorporated into PI matrix to form PI/Al2O3 hybrid films by in situ polymerisation. The effects of Al2O3 additives on the structure, dielectric and mechanical properties of the films were studied. Fourier transform infrared spectroscopy confirmed the successful preparation of PI/Al2O3 hybrid films, and the microstructures of the samples showed a more uniform dispersion of the modified Al2O3 nanoparticles than the unmodified ones in the matrix. The dielectric constant of the films increased with increasing filler content, and the maximum electrical breakdown strength of 311 MV m−1 was obtained with a filler content of 8.0 wt-% modified Al2O3 in the matrix. Both unmodified and modified Al2O3-reinforced PI hybrids demonstrated improved mechanical properties compared with the PI matrix. Moreover, the properties of films with Al2O3 modified by KH550 were better.
TsaiM. H., HuangY. C., TsengI. H., YuH. P., LinY. K. and HuangS. L.: ‘ Thermal and mechanical properties of polyimide/nano-silica hybrid films’, Thin Solid Films, 2011, 519, 5238–5242. doi: 10.1016/j.tsf.2011.01.167
2.
ParkO. K., KimS. G., YouN. H., KuB. C., HuiD. and LeeJ. H.: ‘ Synthesis and properties of iodo functionalized grapheme oxide/polyimide nanocomposites’, Compos. B Eng., 2014, 56, 365–371. doi: 10.1016/j.compositesb.2013.08.065
3.
CuiG. H., LiuW., YuanL. X., WuD. Z. and WuZ. P.: ‘Transition of polyimide/a-Fe2O3 to polyimide/Fe3O4 nanocomposite films by adjusting thermal treatment surroundings of ion-doped substrates’, RSC, 2013, 3, 14390–14396. doi: 10.1039/c3ra41461b
4.
LuoY. L. and MatsuoM.: ‘Morphology of carbon/TiC composite films prepared by carbonization of polyimide/titania composites’, Polym. Bull., 2010, 64, 939–951. doi: 10.1007/s00289-009-0230-0
5.
LiW. P., LiuH. C. and FengL. L.: ‘Preparation and anti-atomic oxygen erosion properties of OPPOSS/PI composites’, Int. J. Min. Met. Mater., 2013, 20, 994–1000. doi: 10.1007/s12613-013-0826-0
6.
VerkerR., AtarN., QueroF., EichhornS. J. and GrossmanE.: ‘Tensile stress effect on the macromolecular orientation and erosion mechanism of an atomic oxygen irradiated polyimide’, Polym. Degrad. Stabil., 2013, 98, 997–1005. doi: 10.1016/j.polymdegradstab.2013.02.009
7.
LiW., GuoX. X. and FangJ. H.: ‘Synthesis and properties of sulfonated polyimide–polybenzimidazole copolymers as proton exchange membranes’, J. Mater. Sci., 2014, 49, 2745–2753. doi: 10.1007/s10853-013-7977-2
8.
HuangY. X., TianX. B., LvS. X., FuR. K.Y. and ChuP. K.: ‘Mechanical and optical characteristics of multilayer inorganic films on polyimide for anti-atomic-oxygen erosion’, Appl. Surf. Sci., 2012, 258, 5810–5814. doi: 10.1016/j.apsusc.2012.02.104
9.
DuB. X. and XiaoM.: ‘Effects of thermally conducting particles on resistance to tracking failure of polyimide/BN composites’, IEEE T Dielect. El. In., 2014, 21, 1565–1572. doi: 10.1109/TDEI.2014.004310
YorifujiD. and AndoS.: ‘Enhanced thermal conductivity over percolation threshold in polyimide blend films containing ZnO nano-pyramidal particles: advantage of vertical double percolation structure’, J. Mater. Chem., 2011, 21, 4402–4407. doi: 10.1039/c0jm04243a
12.
GhezelbashZ., AshouriD., MousavianS., GhandiA. H. and RahnamaY.: ‘Surface modified Al2O3 in fluorinated polyimide/Al2O3 nanocomposites: synthesis and characterization’, Bull. Mater. Sci., 2012, 35, 925–931. doi: 10.1007/s12034-012-0385-4
13.
SugumaranC. P.: ‘Experimental investigation on dielectric and thermal characteristics of nanosized alumina filler added polyimide enamel’, J. Electr. Eng. Technol., 2014, 9, 978–983. doi: 10.5370/JEET.2014.9.3.978
14.
AliasA., AhmadZ. and IsmailA. B.: ‘Preparation of polyimide/Al2O3 composite films as improved solid dielectrics’, Mater. Sci. Eng. B Adv., 2011, 176, 799–802. doi: 10.1016/j.mseb.2011.04.001
15.
CuiX. P., ZhuG. M., LiuW. Y., WangK., RenF., FuH. M. and YanX. G.: ‘Mechanical and dielectric properties of polyimide/silica nanocomposite films’, Plast. Rubber Compos., 2015, 44, 435–439. doi: 10.1080/14658011.2015.1104087
16.
ShekC. H., LaiJ. K. L., GuT. S. and LinG. M.: ‘Transformation evolution and infrared absorption spectra of amorphous and crystalline nano-Al2O3 powders’, Nanostruct. Mater., 1997, 8, 605–610. doi: 10.1016/S0965-9773(97)00201-8
17.
BuW. B., YinJ. H., TianF. Q., LiG. and LeiQ. Q.: ‘Effect of corona ageing on the structure changes of polyimide and polyimide/Al2O3 nanocomposite films’, J. Electrostat., 2011, 69, 141–145. doi: 10.1016/j.elstat.2011.03.001
18.
ZhanJ. Y., TianG. F., WuZ. P., QiS. L. and WuD. Z.: ‘Preparation of polyimide/BaTiO3/Ag nanocomposite films via in situ technique and study of their dielectric Behavior’, Chinese J. Polym. Sci., 2014, 32, 424–431. doi: 10.1007/s10118-014-1413-1
19.
LiH. Y., LiuG., LiuB., ChenW., ChenS. T.: ‘Dielectric properties of polyimide/Al2O3 hybrids synthesized by in-situ polymerization’, Mater. Lett., 2007, 61, 1507–1511. doi: 10.1016/j.matlet.2006.07.063
20.
LeeJ., KoY. and KimJ.: ‘Effect of poly(amic acid)-treated BaTiO3 on the dielectric and mechanical properties of BaTiO3/polyimide composites’, Macromol. Res., 2010, 18, 200–203. doi: 10.1007/s13233-009-0109-9
21.
BabanzadehS., Mehdipour-AtaeiS. and MahjoubA. R.: ‘Effect of nanosilica on the dielectric properties and thermal stability of polyimide/SiO2 nanohybrid’, Des. Monomers Polym., 2013, 16, 417–424. doi: 10.1080/15685551.2012.747159
22.
MaP. C., NieW., YangZ. H., ZhangP. H., LiG., LeiQ. Q., GaoL. X., JiX. L. and DingM. X.: ‘Preparation and characterization of polyimide/Al2O3 hybrid films by sol–gel process’, J. Appl. Polym. Sci., 2008, 108, 705–712. doi: 10.1002/app.27540
23.
WangY. K., ZhuG. M., TangY. S., XieJ. Q., LiuT. T. and LiuZ.: ‘Mechanical and shape memory behavior of chemically cross-linked SBS/LDPE blends’, J. Polym. Res., 2014, 21, 405–414. doi: 10.1007/s10965-014-0405-8
24.
LongunJ., WalkerG. and IrohJ. O.: ‘Surface and mechanical properties of graphene–clay/polyimide composites and thin films’, Carbon, 2013, 63, 9–22. doi: 10.1016/j.carbon.2013.06.024
25.
XuZ. W., ZhangJ. G., ShanM. J., LiY. L., LiB. D., NiuJ. R., ZhouB. M. and QianX. M.: ‘Organosilane-functionalized graphene oxide for enhanced antifouling and mechanical properties of polyvinylidene fluoride ultrafiltration membranes’, J. Membrane Sci., 2014, 458, 1–13. doi: 10.1016/j.memsci.2014.01.050
26.
SinghB. P., SinghD., MathurR. B. and DhamiT. L.: ‘Influence of surface modified MWCNTs on the mechanical, electrical and thermal properties of polyimide nanocomposites’, Nanoscale Res. Lett., 2008, 3, 444–453. doi: 10.1007/s11671-008-9179-4
27.
KomarovP. V., ChiuY. T., ChenS. M. and ReinekerP.: ‘Investigation of thermal expansion of polyimide/SiO2 nanocomposites by molecular dynamics simulations’, Macromol. Theor. Simul., 2010, 19, 64–73.
