Highly crosslinked nanocomposites of aromatic dicyanates/SiO₂ via the sol–gel method

Abstract

Highly crosslinked nanocomposites of bisphenol A dicyanate (BADCy) containing silica clusters were successfully prepared via the sol-gel process. The silica clusters were generated from various metal alkoxide precursors, including methyltrimethoxysilane (TMOS), 3-glycidoxypropyltrimethoxysilane (GPOS), and 2-(3,4-epoxycyclohexyl) ethyltrimethoxysilane (ECOS). The metal alkoxide precursors GPOS and ECOS were, in turn, used as coupling agents. Three kinds of systems involving BADCy/ TMOS, BADCy/coupling agent, and BADCy/TMOS/coupling agent were individually prepared and thoroughly investigated using various methods. Each kind of system was of a particular characterization and morphology and had distinct physical and dielectric properties. Isolated silica clusters on a nanoscale were homogenously distributed in the highly crosslinked BADCy/TMOS hybrid system. The characterization of BADCy/TMOS nanocomposites showed improved physical properties, when compared with the neat BADCy network. The particle sizes can be controlled by adding different amounts of TMOS and are slightly increased (in the range of 50-105 nm) with increasing TMOS content. On the other hand, in the highly crosslinked BADCy/coupling agent hybrid system, the silica clusters were tethered to the BADCy matrix by the coupling agent. An oxazoline linkage was detected during the reaction of cyanate groups in BADCy with the epoxide groups in the coupling agent. These nanocomposites exhibited weakened mechanical properties but are of a smaller and more homogenous particle size in the range of 30-50 nm, irrespective of the silica content. Finally, the BADCy/TMOS/coupling agent system was successfully designed to combine the advantages of the two systems mentioned above.

Low surface free energy cyanate ester–silica hybrid (CE–SiO2) nanomaterials for low k dielectric applications

“…These materials can be synthesized via several different approaches and one that has been particularly successful is the in situ polymerization of metal alkoxide precursors, in the presence of polymer matrices via the sol-gel method. 9 The sol-gel technique is a convenient method for the synthesis of nanocomposite materials consisting of organic and inorganic compounds. [10][11][12][13][14][15][16][17][18][19][20][21] By application of the sol-gel process, organic-inorganic hybrid materials can be generated using different synthetic techniques with various inorganic and organic starting compounds.…”

Silicon-containing trifunctional and tetrafunctional cyanate esters: Synthesis, cure kinetics, and network properties

“…A strategy used to provide thermooxidative protection in cyanurate polymer networks that has been explored through much recent investigation is the incorporation of silicon or siloxy moieties in the form of monomers and cocuratives, blends and modifiers, silica nanoparticles, clay nanoplatelets, or other silicon‐containing nanostructures including oligomeric silsesquioxanes . While the addition of silicon in fully oxidized form (i.e., as SiO 2 ) can provide an in‐place barrier to oxygen permeation, the use of unoxidized organosilicon moieties or partly oxidized silicates allows for the in situ generation of a protective barrier during high‐temperature oxidation or exposure to energetic forms of oxygen (such as atomic oxygen in low Earth orbit) .…”

Research Progress of Heat Hv Insulation Resistance of Macromolecular Composite Materials

“…Organic insulating materials: shellac, resin, rubber, cotton yarn, paper, hemp, rayon, mostly Jue Yuan Qi, winding wires used to manufacture of coating insulation content to wait. Mixed insulating material for above two kinds of material made by processing various molding insulating materials used as the base, hull, electric [7][8][9][10][11].…”

“…Organic insulating materials: shellac, resin, rubber, cotton yarn, paper, hemp, rayon, mostly Jue Yuan Qi, winding wires used to manufacture of coating insulation content to wait. Mixed insulating material for above two kinds of material made by processing various molding insulating materials used as the base, hull, electric [7][8][9][10][11].Insulation material and macro properties such as electrical properties, thermal, mechanical properties, resistance to chemicals, resistant to climate change, corrosion resistance performance and its chemical composition, molecular structure has close relationship. Inorganic solid insulation material is mainly composed of silicon, boron and many kinds of metal oxide mainly composed by ionic structure, main characteristic for heat-resistance, high, average temperature more than 180 ℃ work, good stability and resistance to atmospheric aging sexual anticorrosion chemical resistance and long-term under the action of the electric field good aging properties; But brittle high, impact resistance of low intensity, high voltage and low tensile strength.…”