Lecture 11b Hybrid

Interpenetrating Networks

Making Hybrid Materials: Class 1E(Interpenetrating network or IPN)

•Two lightly crosslinked networks •Cannot be untangled. •Each network has different mechanical Properties.

• Together they are stronger, tougher than sum of the individual polymers = synergistic

All organic IPN adhesives & coatings

Simultaneous Interpenetrating networks

•The two networks assembled at the same time•Phase separation of hard colloidal particles would ruin IPN

Sequential Interpenetrating networks

•The two networks are not assembled at the same time•In this case the inorganic network is assembled before the organic

If phase separation of particles occurs, it is not an IPN

This is a hybrid, inorganic filled polymer, an extreme case of Class 1C. However, many publications refer to similar hybrids as IPN’s

Synthesis of poly(methylphenylsiloxane)/phenylene-silica hybrid material with interpenetrating networks and its performance as thermal resistant coating

Gao, D. and Jia, M. J. Appl. Polym. Sci. 2012. doi: 10.1002/app.38372

Synthesis of poly(methylphenylsiloxane)/phenylene-silica hybrid material with interpenetrating networks and its performance as thermal resistant coating

Tensile10-20 MPa

Stable > 300 °C

Gao, D. and Jia, M. J. Appl. Polym. Sci. 2012. doi: 10.1002/app.38372

Organic–inorganic polymer hybrids based on unsaturated polyester

Journal of Non-Crystalline Solids, 2002, 311, 195–198

•Sol-gel polymerization of phenyltriethoxysilane in presence of Linear organic polymer •Photochemical cure of organic network

What about a forming a particle based gel in a monomer as solvent, then polymerize it

Macromolecules, 1991, 24 (19), pp 5481–5483

Simultaneous Interpenetrating networks: "Inverse" organic-inorganic composite materials.

Monomer containing both silica and organic components splits apart

Macromolecules, 1991, 24 (19), pp 5481–5483

Simultaneous Interpenetrating networks: "Inverse" organic-inorganic composite materials.

For a hybrid to be an IPN, there must be a non-linear, synergistic effect on the mechanical properties

More recent interpenetrating network: tetrabenzylalkoxysilane sol-gel

Angew. Chem. Int. Ed. 2009, 48, 8254 –8258

Angew. Chem. Int. Ed. 2007, 46, 628 –632