Polyimide (PI) aerogels are open-celled materials with high porosity, low density, excellent mechanical property and high thermal stability. Linear PI aerogels exhibit drastic shrinkage during the fabrication process. Cross-linked PI aerogels were usually fabricated by utilizing the costly cross-linking agents such as 1,3,5-triaminophenoxybenzene or octa-(aminophenyl)silsesquioxane. Herein, amino functionalized multi-walled carbon nanotubes (MWCNTs-NH2) were prepared by amidation reaction; PI/MWCNTs-NH2 composite aerogels were fabricated by adding MWCNTs-NH2 to anhydride end-capped poly(amic acid) (PAA), chemical imidization of PAA and supercritical carbon dioxide drying. The microstructures, pore size, elastic modulus, thermal properties and other physical properties of the obtained PI/MWCNTs-NH2 composite aerogels were investigated. The results showed that MWCNTs-NH2 could act as a cross-linker of PI because the amino groups of MWCNTs-NH2 could react with the terminal anhydride groups of PAA. With the addition of MWCNTs-NH2, the shrinkage of PI/MWCNTs-NH2 composite aerogels decreased. The densities and Young’s moduli of PI/MWCNTs-NH2 composite aerogels also decreased. The PI/MWCNTs-NH2 composite aerogels had coralline-like structure with mesopores (average pore size: 11–20 nm). The PI/MWCNTs-NH2 composite aerogels also exhibited decent thermal stability and thermal insulating property.
GuoHMeadorMABMcCorkleL. Polyimide aerogels cross-linked through amine functionalized polyoligomeric silsesquioxane. ACS Appl Mater Inter2011; 3(2): 546–552.
2.
PeiXZhaiWZhengW. Preparation and characterization of highly cross-linked polyimide aerogels based on polyimide containing trimethoxysilane side groups. Langmuir2014; 30(44): 13375–13383.
3.
SaiHXingLXiangJ. Flexible aerogels based on an interpenetrating network of bacterial cellulose and silica by a non-supercritical drying process. J Mater Chem A2013; 1(27): 7963–7970.
YangHKongXZhangY. Mechanical properties of polymer-modified silica aerogels dried under ambient pressure. J Non-Cryst Solids2011; 357(19): 3447–3453.
8.
YanPZhouBDuA. Synthesis of polyimide cross-linked silica aerogels with good acoustic performance. RSC Adv2014; 4: 58252–58259.
9.
YangXCranstonED. Chemically cross-linked cellulose nanocrystal aerogels with shape recovery and superabsorbent properties. Chem Mater2014; 26(20): 6016–6025.
10.
MeadorMABAlemánCRHansonK. Polyimide aerogels with amide cross-links: a low cost alternative for mechanically strong polymer aerogels. ACS Appl Mater Inter2015; 7(2): 1240–1249.
11.
RhineWWangJBegagR.Polyimide aerogels, carbon aerogels, and metal carbide aerogels and methods of making same. U.S. Patent 7,074,880, USA, 2016.
12.
MeadorMABMalowEJSilvaR. Mechanically strong, flexible polyimide aerogels cross-linked with aromatic triamine. ACS Appl Mater Inter2012; 4(2): 536–544.
LiuPTranTQFanZ. Formation mechanisms and morphological effects on multi-properties of carbon nanotube fibers and their polyimide aerogel-coated composites. Compos Sci Technol2015; 117: 114–120.
15.
LiuLFangZGuA. Amino functionalization effect on the microtribological behavior of carbon nanotube/bismaleimide nanocomposites. J Appl Polym Sci2009; 113(6): 3484–3491.
16.
CuiLJGengHZWangWY. Functionalization of multi-wall carbon nanotubes to reduce the coefficient of the friction and improve the wear resistance of multi-wall carbon nanotube/epoxy composites. Carbon2013; 54: 277–282.
17.
ZhangBChakoliANZangW. A comparative study on effect of aromatic polyimide chain conformation on reinforcement of carbon nanotube/polyimide nanocomposites. J Appl Polym Sci2014; 131(13).
18.
HaghgooMYousefiAAMehrMJZ. Characterization of multi-walled carbon nanotube dispersion in resorcinol-formaldehyde aerogels. Micropor Mesopor Mater2014; 184: 97–104.
KongHGaoCYanD. Functionalization of multi-walled carbon nanotubes by atom transfer radical polymerization and defunctionalization of the products. Macromolecules2004; 37(11): 4022–4030.
LiZZouHLiuP. Morphology and properties of porous polyimide films prepared through thermally induced phase separation. RSC Adv2015; 5(47): 37837–37842.
28.
ShenJHuangWWuL. Thermo-physical properties of epoxy nanocomposites reinforced with amino-functionalized multi-walled carbon nanotubes. Compos A Appl S2007; 38(5): 1331–1336.
29.
RamanathanTFisherFTRuoffRS. Amino-functionalized carbon nanotubes for binding to polymers and biological systems. Chem Mater2005; 17(6): 1290–1295.
30.
LiuYCuiGLuoC. Synthesis, characterization and application of amino-functionalized multi-walled carbon nanotubes for effective fast removal of methyl orange from aqueous solution. RSC Adv2014; 4(98): 55162–55172.
31.
ZhangCZhuFWangZ. Amino functionalization of multi-walled carbon nanotubes by gamma ray irradiation and its epoxy composites. Polym Compos2012; 33(2): 267–274.
32.
DatsyukVKalyvaMPapagelisK. Chemical oxidation of multi-walled carbon nanotubes. Carbon2008; 46(6): 833–840.
LiuTTongYZhangWD. Preparation and characterization of carbon nanotube/polyetherimide nanocomposite films. Compos Sci Technol2007; 67(3): 406–412.
35.
WangXHuHYeQ. Superamphiphobic coatings with coralline-like structure enabled by one-step spray of polyurethane/carbon nanotube composites. J Mater Chem2012; 22(19): 9624–9631.
36.
HeSZhangYShiX. Rapid and facile synthesis of a low-cost monolithic polyamide aerogel via sol-gel technology. Mater Lett2015; 144: 82–84.
37.
WuSDuAHuangS. Effects of monomer rigidity on the microstructures and properties of polyimide aerogels cross-linked with low cost aminosilane. RSC Adv2016; 6(27): 22868–22877.
