Synthesis and study of new radial organic/inorganic hybrid epoxides

Abstract

A new approach to the synthesis of reactive organic/inorganic hybrid molecules was developed. Alternating hydrocarbon and siloxane segments were introduced into the arms of radial oligomers using hydrosilation chemistry. Cycloaliphatic and glycidyl epoxy-terminal systems with bisphenol A-based aromatic hydrocarbon cores and siloxane units derived from 1,1,3,3-tetramethyldisiloxane were synthesized and fully characterized (molecules 7 and 6, respectively). The cationic UV and thermal curing behavior of these two new radial hybrid epoxies was investigated using photo-and thermal-differential scanning calorimetry. Hybrid cycloaliphatic epoxy 7 exhibited good UV curing kinetics and photopolymerized to high conversion. The glycidyl analog 6 exhibited poor UV curing kinetics, but was readily cured using 2-ethyl-4-methylimidazole as a nucleophilic curing agent. Both hybrid epoxysiloxanes exhibited extensive thermal cationic cure. The physical properties of cured films of the two new radial epoxysiloxanes were studied and compared with various commercially available hydrocarbon and siloxane benchmark materials. The cured systems exhibited lower moisture uptake and better thermal stability than most hydrocarbon epoxies examined. Several visually compatible blends of the new hybrid molecules with common hydrocarbon resins were identified, and in general organic compatibility was found to be intermediate among selected siloxane-containing benchmarks. Molecules 6 and 7 represent progress towards the goal of synthesizing highly functional organic/inorganic hybrid molecules which combine the best attributes of both hydrocarbon epoxides and siloxane materials.

Thermodynamic Analysis of Trisiloxane Surfactant Adsorption and Aggregation Processes

“…Thanks to the presence of the Si-H bond, it is possible to attach all kinds of substituents, e.g. amino [1][2][3][4], epoxycarbo [5][6][7], aryl and methacrylic [8,9] or polyether [4,10,11] groups. Modification of polysiloxanes with organic groups provides a wide range of hybrid materials combining the properties of polysiloxanes (thermal resistance, oxidation resistance, gas permeability, low surface tension, excellent dielectric properties, physiological neutrality and moisture resistance) with those of organic functional groups.…”

Poly(n‐alkylsilsesquioxane)s: Synthesis, characterization, and modification with poly(dimethylsiloxane)

“…Polysiloxanes have technological relevance in coatings,1–5 membranes,6–16 precursor for ceramics,17–23 among others 5, 23. The incorporation of siloxane units in polyamides,24 polyimides,25–28 epoxy resins,29–31 polyester resins,32 and polyurethanes33 often improves the mechanical properties,26, 28 resistance against corrosion,31, 32 thermal stability,29, 33 and membrane performance27 of these polymers.…”

Synthesis and characterization of an anticratering agent based on APTES for cathodic electrocoatings

“…Organic-inorganic hybrid materials show both inorganic and organic characteristics [17][18][19][20][21]. Organic resins modified by silanes can improve resistance against surface defects, thermal resistance and weathering [22][23][24][25][26][27][28].…”