IN SITU FABRICATION OF HIGH PERFORMANCE POLYIMIDE/TYROSINE-MODIFIED LAYERED SILICATE NANOCOMPOSITES

Abstract

Several novel organicÀinorganic hybrids consisting of high performance polyimide (PI) and organically modi¯ed montmorillonite (OMMT) with trifunctional swelling agent were successfully prepared by in situ polymerization technique. In this way, at¯rst, OMMT was prepared by surface treatment of Cloisite Na þ with protonated form of bioactive L-tyrosine amino acid. Amine functional groups of this swelling agent formed an ionic bond with the negatively charged silicates, whereas the remaining acidic and phenolic functional groups are available for further interaction with PI chains. Then, organo-soluble PI with benzimidazole pendent group was prepared from pyromellitic dianhydride and 4-(3, 5-diaminophenyl)-benzimidazole in dry N; N-dimethylacetamide. PI/OMMT nanocomposites enclosing 1À10 wt.% of OMMT were successfully prepared by an in situ polymerization reaction through thermal imidization up to 300 C. Also, the relationship between the properties and OMMT content of the PI hybrid¯lms were examined using Fourier-transform infrared spectroscopy, X-ray di®raction measurements and electronic microscopy (FE-SEM and TEM). The silicate layers in the polymer matrix were exfoliated as con¯rmed by XRD, FE-SEM and TEM techniques. The PI/OMMT¯lms have good optical transparencies, and are almost colorless. The thermal stability of hybrids such as the decomposition temperature and weight residue at 800 C were also increased with increasing OMMT content.

Novel and processable polyimides with a N-benzonitrile side chain: thermal, mechanical and gas separation properties

“…Aromatic polyimides (PI)s are a class of thermally stable polymers due to their astonishing thermal and chemical resistance, good lm forming ability, low dielectric constant, superior mechanical and physical properties as well as excellent electrical properties. [1][2][3][4] PIs also possess outstanding dimensional stability under loads, which allows their use in hightemperature environments. Certainly, the presence of imide rings and subsequently charge transfer complexes in the polymer backbone lead directly to a favorable balance of chemical and mechanical properties.…”

Surface Treatment of ZrO2Nanoparticles with Biosafe Citric Acid and Its Utilization for the Synthesis of L-leucine Based Poly(Amide–Imide) Nanocomposites

“…NCs can classified as ceramic metal, metal matrix and polymer matrix NCs according their matrix. Filler of NCs can be metallic nanoparticles (NPs), layer nano silicate, graphen and carbon nanotubes [3][4][5][6][7] .…”

Fabrication and characterization of novel highly transparent and organo-soluble poly(ether imide)s thin film for gas separation

“…[7][8][9][10][11][12] However, for numerous applications, these polymers should have high thermal stability, good film-forming ability, sufficient organo-solubility and improved chemical resistance. Thus, these polymers are generally used in the fields of adhesives, sealants, electrical packaging, and interlayer dielectrics, as high temperature insulators for aircraft wire coatings, as membranes for gas separation and as materials in flexible printed circuits materials.…”

“…Thus, these polymers are generally used in the fields of adhesives, sealants, electrical packaging, and interlayer dielectrics, as high temperature insulators for aircraft wire coatings, as membranes for gas separation and as materials in flexible printed circuits materials. [7][8][9][10][11][12] However, for numerous applications, these polymers should have high thermal stability, good film-forming ability, sufficient organo-solubility and improved chemical resistance. However, wholly aromatic PIs, due to their high melting or glass-transition temperatures (T g 's) and their limited solubility in most organic solvents and transparency deficiencies, do not present the optimum properties for many applications.…”