TECHNOLOGY CATEGORIES: MEMBRANES; SPECIALTY COATINGS; DELIVERY SYSTEMS

KEYWORDS: Poly(amidoamine-organosilicon) dendrimers, PAMAMOS, Inverted unimolecular nanoscopic micelles, Copolymeric dendrimers, Surface

DESCRIPTION: PAMAMOS dendrimers are a new class of globular, radially layered, copolymeric nano-sized molecules consisting of hydrophilic and nucleophilic polyamidoamine (PAMAM: -[(CH₂)₂-C(O)-N(H)-(CH₂)₂-N]n<) interiors and hydrophobic organosilicon (OS: -R-SiX₃) exteriors. They can be thought of as spheroidal, highly branched (bush-like) core-shell nanoparticles or as inverted, covalently bonded, unimolecular micelles that are stable to changes in solvents, pH and temperature. They can be made with chemically inert X = -Si(CH₃)₃ or reactive X = –Si(CH₃)₂CH=CH₂, –SiCH₃(OCH₃)₂ or –Si-(OCH₃)₃ end-groups. PAMAMOS dendrimers range from 1 to about 8 nm in hydrodynamic diameter in methanol, increasing by about 1 nm per generation. In solutions, they behave as flexible, solvent draining, Newtonian liquids. Depending on the nature of the end-groups they may be soluble in water, methanol, ethanol, chloroform, tetrahydrofuran, toluene, or their mixtures. 

BENEFITS: The –SiOCH₃ functionalized PAMAMOS are excellent precursors for dendrimer-based, honeycomb-like, 3D, crosslinked networks that can be easily formed into films, sheets, coatings or membranes with mechanical properties ranging from highly elastomeric to rigid, plastomeric. The vinyl-functionalized variants are useful for further chemical modification, including preparation of various multi-arm star polymers with polymethylene or polysiloxane arms. These multiarm star polymers as well as PAMAMOS dendrimers with Si(CH₃)₃ end-groups are excellent metal ion encapsulators and phase transfer agents.         

STAGE OF DEVELOPMENT: The X = –SiCH₃(OCH₃)₂ and –Si-(OCH₃)₃ variants are commercially available from Dendritech, Inc. in Midland, MI, in two homologous series of generations 0 through 7 having from 8 to over 500 end-groups since 2003. Variants with X = -Si(CH₃)₃ or –Si(CH₃)₂CH=CH₂ end-groups may be made available by special arrangement. The former two variants are also available from Sigma-Aldrich.

NEXT STEPS: Contact us or Dendritech Inc. for your special needs.

PATENT: Dvornic, P.R.; de Leuze-Jalloulli, A.M.; Swanson, D.; Owen, M.J.; Perz, S.V.; Radially Layered Copoly(amidoamine-organosilicon) Dendrimers, US Pat. 5,739,218, 1998.

REFERENCES: (a) Dvornic, P.R., “PAMAMOS: The First Commercial Silicon-Containing Dendrimers and their Applications”, J. Polym. Sci. Part A: Polym. Chem., 2006, 44, 2755. (b) Dvornic, P.R.; de Leuze-Jallouli, A.M.; Owen, M.J.; Perz, S.V., Radially Layered Poly(amidoamine-organosilicon) Dendrimers, Macromolecules, 2000, 33, 5366.