Side Chain Dendritic Polymers:  Synthesis and Physical Properties

Abstract

A series of side chain dendritic polymers (SCDP) was produced by copolymerization of dendritic diols of the second, third, and fourth generation with four different semirigid and flexible diisocyanates. The polymerization reactions were conducted both in solution and in bulk. The degree of polymerization and molecular weight distribution of SCDPs were greatly influenced by the flexibility of the diisocyanates and the nature of the reaction medium. The conformation of SCDPs in solution and its dependence on the molecular weight were examined with the aid of intrinsic viscosity ([η]) measurements. According to the results obtained, SCDPs based on the third and fourth generation monodendrons changed in conformation from spherically to cylindrically shaped structures at a certain molecular weight. The supramolecular assembly of dendritic monoand polymers in bulk was investigated by X-ray diffraction measurements. It was demonstrated that these macromolecules were, in principle, able to form body-centered cubic lattices. Some results suggested that the ability to form such a type of higher order structures increased as a result of polymerization of dendritic monomers. These findings were supported by molecular dynamics simulations conducted on dendritic monoand polymers. By means of such calculations, we also studied the effect of the degree of polymerization on the molecular conformation up to a degree of polymerization of seven. We derived the double logarithmic plots of the calculated values of the radius of gyration (R g ) versus molecular weight (R g ∝ M ν ). In a medium consisting of a poor solvent, the data scaled according to ν ) 0.36, which agreed well with some of the theoretical predictions made for the conventional dendrimers (theory: ν ) 0.33). In a good solvent, however, the conformation of SCDPs approached the Gaussian distribution statistics.

Dendronized Polymers: Synthesis, Characterization, Assembly at Interfaces, and Manipulation

“…[40] This was concluded from X-ray diffraction patterns obtained from Si plates coated with this polymer and monomer 18. A series of Bragg peaks for the polymer showed the existence of an ordered structure.…”

“…Fre  chet-type dendrons [19] are drawn in an abbreviated form, which is explained in Figure 3. The monomers are polymerized by radical polymerization (2, [5b, 20] 3, [21] 4, [22] 5, [23] 6, [24] 7, [25,26] 8, [27] 9, [28] 10, [24] 11, [29] and 12, [30] ), insertion polymerization (13 [31] ), ring-opening metathesis polymerization (ROMP) [32] (14 [33,34] ), Suzuki polycondensation (SPC) [35] with 17 (15 [36] and 16 [37] ) and 23 (20, [38] 21, [39] and 22 [39] ), polyaddition with 19 under polyurethane formation (18 [40] ), and Heck coupling of 24 with 25.…”

Dendronisierte Polymere: Synthese, Charakterisierung, Grenzflächenverhalten und Manipulation

“…Dendronen vom Fre  chet-Typ [19] sind in einer abgekürzten Form dargestellt, die in Abbildung 3 erläutert wird. Die Monomere wurden polymerisiert durch radikalische Polymerisation (2, [5b, 20] 3, [21] 4, [22] 5, [23] 6, [24] 7, [25,26] 8, [27] 9, [28] 10, [24] 11 [29] und 12, [30] ), Insertionspolymerisation (13 [31] ), Ringöffnungsmetathese-Polymerisation (ROMP) [32] (14 [33,34] ), Suzuki-Polykondensation (SPC) [35] mit 17 (15 [36] und 16 [37] ), 23 (20, [38] 21, [39] sowie 22 [39] ), Polyaddition mit 19 unter Polyurethanbildung (18 [40] ) und Heck-Kupplung von 24 mit 25. [41] Dendronisierte Oligomere mit Endiin-WHEs wurden ebenfalls hergestellt.…”

Rouse Dynamics of Polymer Networks Bearing Dendritic Wedges

“…We mention here exemplarily side chain dendritic polymers, consisting of linear chains with pendant dendritic groups. [7][8][9] Recently, even more complex polymer structures were synthesized, namely polyurethane networks bearing dendritic wedges of different generations. 10 In these networks the dendritic wedges are attached to the middle of each chain which forms the network.…”