Polypropylenimine dendrimers: Improved synthesis and characterization

Brabander, E. M. M. De; Brackman, J.; Mure‐Mak, M.; Man, Hua; Hogeweg, Marjo; Keulen, J.; Scherrenberg, Rolf; Coussens, Betty; Mengerink, Ynze; Wal, S.J. van der

doi:10.1002/masy.19961020104

Cited by 47 publications

(29 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Synthesis and characterisation: We have synthesized two series of poly(propylene imine) dendrimers, [3,16] functionalized with pentyloxy and decyloxy cyanobiphenyl mesogens, denoted as DAB-dendr-(NHCOÀC 5 ÀCBPh) n (n 1, 3; n 4, 4; n 16, 5; n 64, 6) and DAB-dendr-(NHCOÀC 10 ÀCBPh) n (n 1, 9; n 4, 10; n 16, 11; n 64, 12), respectively (Schemes 1a and 1b).…”

Section: Resultsmentioning

confidence: 99%

Liquid-Crystalline Properties of Poly(propylene imine) Dendrimers Functionalized with Cyanobiphenyl Mesogens at the Periphery

Baars

Söntjens

Fischer³

et al. 1998

Chem. Eur. J.

143

View full text Add to dashboard Cite

Three generations poly(propylene imine) dendrimers with 4, 16, and 64 terminal amine groups have been functionalized with pentyloxycyanobiphenyl and decyloxycyanobiphenyl mesogens. The liquid-crystalline properties of these dendrimers have been studied in detail by differential scanning calorimetry, optical polarization microscopy, and X-ray diffraction. All the mesogenic dendrimers orient into a smectic A mesophase. Thermal properties are influenced to a large extent by the spacer length, showing g 3S A 3I transitions for the dendritic mesogens with the pentyloxy spacers and K 3S A 3I transitions for the ones with a decyloxy spacer. In the latter, the temperature range of the mesophase increases with dendrimer generation. Mesophase formation in the case of the pentyloxy series is more difficult compared with the corresponding decyloxy analogues, when the transition enthalpies and the kinetics of obtaining microscopic textures are considered. The effect of generation on mesophase formation cannot be clearly distinguished, although in the case of the fifth-generation dendrimer with a decyloxy spacer, microscopic textures could be obtained more easily, compared with the lower generations. X-ray diffraction measurements of oriented samples indicate that the cyanobiphenyl endgroups of both series orient into an antiparallel-overlapping interdigitated structure. The observed S A -layer spacings are independent of the dendrimer generation for both spacer lengths, indicating that the dendritic backbone has to adopt a completely distorted conformation, even for the higher generations.

show abstract

Section: Resultsmentioning

confidence: 99%

Liquid-Crystalline Properties of Poly(propylene imine) Dendrimers Functionalized with Cyanobiphenyl Mesogens at the Periphery

Baars

Söntjens

Fischer³

et al. 1998

Chem. Eur. J.

143

View full text Add to dashboard Cite

show abstract

“…1) was carried out as previously described (Ashton et al, 1997). They were prepared by modification of poly(propylene imine) dendrimers (de Brabander-van der Berg et al, 1996;de Brabander-van der Berg and Meijer, 1993) of ''generation number'', g ¼ 1 to 5 by attaching spacer armed b-lactose derivatives. In the resulting compounds, lactose residues are attached to the ends of dendritic skeletons via stable amide bonds.…”

Section: Samples and Solventsmentioning

confidence: 99%

Hydrodynamic properties of carbohydrate-coated dendrimers

Корнеева

Jumel

Harding

et al. 1999

Carbohydrate Polymers

View full text Add to dashboard Cite

The hydrodynamic properties of poly(propylene imine) dendrimers, modified with outer-surface b-thiolactosyl residues (''lactodendrimers'') of generation number 1-5, have been investigated by velocity sedimentation, translational diffusion, and viscosity measurements in 0.165% NaCl aqueous solution. It has been demonstrated that apparent molecular weights (from the Svedberg equation) M sD of synthetic lactodendrimers, determined by sedimentation and diffusion experiments, are consistent with complete functionalization of initial poly-(propylene imine) dendrimers with sugar residues. The values of M sD range from 1900 to 45000 Da for generation numbers 1-5. Corresponding hydrodynamic (''equivalent Stokes'') radii range from ϳ10 to ϳ37 Å . Scaling relations of the conformation-dependent sedimentation coefficient, translational diffusion coefficient and intrinsic viscosity with molecular weight have been considered in detail and are all indicative of a spherical molecule with an inhomogeneous distribution of density (Mark-Houwink-Kuhn-Sakurada a, b and , coefficients of ϳ0.24, ϳ0.69 and ϳ0.31, respectively). ᭧

show abstract

“…The most important issue in the reductive amination of nitriles is the control of selectivity towards the primary amine. For the reduction of nitrile groups a Raney‐Cobalt catalyst in the presence of NH 3 was already successfully used in the synthesis of dendrimers50, 51 and in the amino functionalization of polystyrene 52. Using this procedure poly[(glycidol‐aminopropyl)‐ co ‐glycidol]s with number average molecular weights of ∼6,500 and polydispersity indices of ∼1.20 were obtained in good yields (>90%); the ratio of NH 2 /OH groups was in the range of 23/77 to 71/29.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and degradation of biomedical materials based on linear and star shaped polyglycidols

Keul

Möller

2009

J. Polym. Sci. A Polym. Chem.

View full text Add to dashboard Cite

Linear and star shaped polyglycidols (synonym with polyglycerols) are prepared in a controlled ring opening polymerization of protected glycidols. Beside the molar mass and the polydispersity, the architecture of the polyglycidols is controlled by using mono-and multifunctional monoand polydispers initiators. Copolymers of dissimilarly protected glycidols as well as copolymers with nonfunctional oxiranes were prepared by means of anionic polymerization while copolymers of protected glycidol with tetrahydrofuran were prepared by means of cationic polymerization. Polyethers with functional groups in the side chains (functional polyethers) with special emphasis on polyglycidols (containing hydroxymethyl groups in the side chains) were used to prepare multifunctional polymers and (hetero)grafted polymer brushes via chemical and enzyme catalyzed reaction. The potential of poly(glycidol-graft-e-caprolactone)-co-glycidol) prepared via enzyme catalyzed grafting of polyglycidols using e-caprolactone as a monomer and Lipase B from Candida antarctica as a catalyst is presented. Finally, comparative degradation studies of densely and loosely grafted polyglycidols are presented and discussed.

show abstract

Polypropylenimine dendrimers: Improved synthesis and characterization

Cited by 47 publications

References 7 publications

Liquid-Crystalline Properties of Poly(propylene imine) Dendrimers Functionalized with Cyanobiphenyl Mesogens at the Periphery

Liquid-Crystalline Properties of Poly(propylene imine) Dendrimers Functionalized with Cyanobiphenyl Mesogens at the Periphery

Hydrodynamic properties of carbohydrate-coated dendrimers

Synthesis and degradation of biomedical materials based on linear and star shaped polyglycidols

Contact Info

Product

Resources

About