Details

Autor(en) / Beteiligte

• Yang, Jinglei
• Keller, Michael W
• Moore, Jeffery S
• White, Scott R
• Sottos, Nancy R

Titel

Microencapsulation of Isocyanates for Self-Healing Polymers

Ist Teil von

• Macromolecules, 2008-12, Vol.41 (24), p.9650-9655

Ort / Verlag

Washington, DC: American Chemical Society

Erscheinungsjahr

2008

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Microcapsules containing reactive diisocyanate for use in self-healing polymers are successfully fabricated via interfacial polymerization of polyurethane (PU). Isocyanates are potential catalyst-free healing agents for use in humid or wet environments. The preparation of PU prepolymer and microencapsulation of isophorone diisocyanate (IPDI) healing agent are presented. Smooth spherical microcapsules of 40−400 μm in diameter are produced by controlling agitation rate (500−1500 rpm) according to a power law relation (n = −2.24). The PU shell wall thickness varies linearly with capsule diameter, such that the capsules wall thickness to diameter ratio is constant (∼0.05). High yields (∼70%) of a free-flowing powder of IPDI/PU capsules are produced with a liquid core content of 70 wt % as determined by TGA analysis. The microcapsules are stable with only ∼10 wt % loss of IPDI detected after 6 months storage under ambient conditions. Direct mechanical compression testing of microcapsules reveals a brittle fracture mode and normalized shell wall strength that varies with capsule diameter in a power law fashion (n = −0.77).