Structure and mechanical properties of the hybrid films of well dispersed SiO2 nanoparticle in polyimide (PI/SiO2) prepared by sol–gel process

Research Progress and Application of Polyimide-Based Nanocomposites

Polyimide (PI) is one of the most dominant engineering plastics with excellent thermal, mechanical, chemical stability and dielectric performance. Further improving the versatility of PIs is of great significance, broadening their application prospects. Thus, integrating functional nanofillers can finely tune the individual characteristic to a certain extent as required by the function. Integrating the two complementary benefits, PI-based composites strongly expand applications, such as aerospace, microelectronic devices, separation membranes, catalysis, and sensors. Here, from the perspective of system science, the recent studies of PI-based composites for molecular design, manufacturing process, combination methods, and the relevant applications are reviewed, more relevantly on the mechanism underlying the phenomena. Additionally, a systematic summary of the current challenges and further directions for PI nanocomposites is presented. Hence, the review will pave the way for future studies.

A simple method for the sonochemical synthesis of PVA/ZrO2-vitamin B1 nanocomposites: Morphology, mechanical, thermal and wettability investigations

Poly(vinyl alcohol) (PVA) based nanocomposites (NCs) filled by various weight percent of modified ZrO₂ nanoparticles (NPs) with vitamin B₁ (VB₁) up to 7wt% were fabricated via ultrasonication method then was cast to thin films. The ultrasonication was applied for the preparation and modification process asan easy, safe and fast method. Ultrasonic was responsible for great homogeneities of NPs into PVA matrix, which could not be achieved by mechanical or magnetically stirring. The creation of polymer NCs and changes in the structural properties were examined by X-ray diffraction. FT-IR spectroscopy indicated the possible interactions of the ZrO₂-VB₁ NPs with the PVA backbones and also, existence of absorption bands related to PVA and ZrO₂ NPs in the NC structures. The distribution of nano-fillers and uniform morphology of the NCs showed that the ZrO₂-VB₁ NPs were homogeneously dispersed in the polymer matrix in the nanosized scale. UV-Vis analysis shown that the the optical absorption were improved by evolution of ZrO₂-VB₁ NPs content. The tensile strength of PVA film was increased significantly with increasing the ZrO₂-VB₁ NPs content. Thermal gravimetric analysis confirmed that NCs displayed higher thermal stability than the pristine PVA. Also, water contact angle analysis indicated that the hydrophilicity of NC films was enhanced with increasing the concentration of ZrO₂ NPs.

Comparison of hybrid polyimide films with silica and organosilica obtained via sol–gel process

A series of polyimide/silica (PI–S) and polyimide/organosilica (PI–OS) hybrid films were prepared via a sol–gel process from mixtures of poly(amic acid) (PAA) and tetraethoxysilane or a silane coupling agent in solution. The PAA was synthesized from bis-(3-phthalyl anhydride) ether and 1,4-bis (4-aminophenoxy) benzene. The hybrid films were produced via an imidization reaction to form silica particles or a silica network in a polymer matrix through a programmed heating process. The derived films were characterized and compared by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, tensile testing, contact angle measurements, moisture absorption measurements, and dielectric property analysis. Both the PI–S and PI–OS hybrid matrixes showed strong regularity with the increasing silica content and greatly improved thermal stability and mechanical properties. Among them, the PI–OS hybrid films possessed superior interphase interactions and were found to have better physicochemical properties.

Silica-aerogel-powders “jammed” polyimide aerogels with excellent hydrophobicity and conversion to ultra-light polyimide aerogel

In this paper, SAp play a role as the shrinkage inhibiter to fabricate the SAp “jammed” polyimide gels.

Effects of monomer rigidity on the microstructures and properties of polyimide aerogels cross-linked with low cost aminosilane

Polyimide aerogels were formed from polyamide acid oligomers cross-linked by Si–O–Si network structures, which were derived from hydrolysis and condensation reactions of low cost bis(trimethoxysilylpropyl) amine (BTMSPA)viaabsorbed water.

Preparation, characterization and gas separation properties of nanocomposite materials based on novel silane functionalizing polyimide bearing pendent naphthyl units and ZnO nanoparticles

Nanocomposites of polyimide with silane end group and ZnO nanoparticles with good thermal and mechanical properties were prepared and were used for gas separation.