Dynamically tuning transient silicone polymer networks with hydrogen bonding

Abstract

Hydrogen bonds on a silicone polymer permit supramolecular silicones to form transient polymer networks with energy absorbing properties that depend on the number of available OH groups.

Aminosilicones without Protecting Groups: Using Natural Amines

“…Rheological measurements showed that, with increasing angular frequency, the viscosity of T-Vi79-SG builds until there is a crossover of G ′/ G ′′ that indicates, above these frequencies, the material is behaving as an elastomer (Figure B). This behavior is analogous fashion to other sugar silicones. , That is, the presence of the SCH 2 CH 2 in the amine sulfide polymers is, at most, a minor player in affecting the physical properties of the polymer.…”

“…This behavior is analogous fashion to other sugar silicones. 28,41 That is, the presence of the SCH 2 CH 2 in the amine sulfide polymers is, at most, a minor player in affecting the physical properties of the polymer.…”

“…Silicone fluids are normally shear thinning fluids; that is, their viscosity decreases with increased velocity under shear. Sugar silicones by contrast exhibit very different viscoelastic behavior under stress. , Viscous sugar silicones fluids rapidly form “transient polymer networks” under compressive stress that, depending on the sugar content, leads to complete energy absorption or energy relay (e.g., bouncing metal balls). In a rheological experiment, their viscosity builds with frequency.…”

Reprocessable Supramolecular Elastomers of Poly(Siloxane–Urethane) via Self‐Complementary Quadruple Hydrogen Bonding

“…These unprecedented properties are attributed to the dynamic nature of supramolecular bonds, whose energies are low enough to allow bond exchanging under mild conditions. Various types of noncovalent interactions, such as hydrogen bonding, [11,12] ionic bonding, [13][14][15][16][17] and metal-ligand coordination, [18][19][20][21][22] have been exploited to build supramolecular silicone materials. Typical examples are thermoplastic elastomers of poly(siloxane-urethane) [23,24] and poly(siloxane-urea), [25,26] where the hydrogen bonding of urethane/urea units and the phase separation between soft polysiloxane segments and hard polyurethane/polyurea are responsible for their excellent mechanical properties and thermoplastic abilities.…”

Naturally Derived Silicone Surfactants Based on Saccharides and Cysteamine

“…The reaction is normally rather facile to practice and is primarily limited by issues of miscibility [ 20 , 21 ]. Sugar-silicone fluids can exhibit a variety of interesting properties, including the ability to effectively dissipate energy [ 22 , 23 ].…”