Cyclodextrins in Polymer Modification: Diels–Alder Addition of Cyclopentadiene/Methylated‐<i>β</i>‐Cyclodextrin Complex on Unsaturated Polyester and Formation of a New Type of Polypseudorotaxane

Alupei, Valentina; Alupei, Iulian Corneliu; Ritter, Helmut

doi:10.1002/marc.200400442

Cited by 7 publications

(3 citation statements)

References 36 publications

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“…Although the scope of suitable monomers is limited by the aqueous medium, this is a green way to synthesize polymers, which is important for both science and industry 4a. 5a Other compounds besides CD, such as crown ethers and calixarenes, can also be used as hosts. Therefore, this approach can be extended to organic solvents for some systems.…”

Section: Methodsmentioning

confidence: 99%

Controlling Polymer Architecture through Host–Guest Interactions

et al. 2005

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Structure and performance are two fundamental characteristics of a polymeric material. Therefore, controlling the structure to get a desired property remains one of the main goals of polymer chemistry.[1] Nowadays, supramolecular principles are also commonly utilized in the design and synthesis of polymer structures, with cyclodextrin (CD) being one of the most widely used hosts. However, most of these works concern the construction of novel supramolecular systems [2][3][4] rather than controlling the molecular structure of the guest polymer.[5] Herein we report a supramolecular method to control the architecture of polymers. The branched structure of a polymer can be adjusted conveniently using such a method. Moreover, this supramolecular approach is versatile and can be used for the design and preparation of materials with special topological structures, functionalities, and properties.The polycondensation-addition of 1-(2-aminoethyl)piperazine (AP), a BB' 2 monomer, and divinylsulfone (DV), an A 2 monomer, is a typical reaction for preparing hyperbranched polymers [6] by monomer-coupling methods. [7] The difference in reactivity between primary amino and secondary amino groups makes it possible to form an AabB' 2 -type intermediate rapidly; further polymerization gives hyperbranched poly-(sulfone-amine) (PSA).A 1 H NMR experiment in situ revealed that neither AP nor DV react with b-CD, despite its many active hydroxy groups (see Supporting Information). Interestingly, the similarities in the size and polarity of the AP molecule and the b-CD cavity induce complexation, and intermolecular hydrogen bonds between the amino and hydroxy groups also help to stabilize the inclusion compound (IC).1 H NMR and elemental analysis confirmed that AP is located in the cavity of b-CD [8] and forms a 1:1 IC. The equilibrium constant between AP and b-CD was measured by two NMR methods, namely conventional NMR binding titration and NMR diffusion measurements.[9] Both experiments gave a value for K a in the range of (100 AE 10) m À1 . This value is similar to those for ICs between b-CD and various small organic molecules.[9d]A series of PSA samples were then prepared by adjusting the amount of b-CD. The optical rotations of these samples (see Supporting Information) suggest the presence of b-CD in the final products. A comparison of the wide-angle X-ray diffraction (WAXD) and NMR spectra before and after polymerization reveals that reaction between AP and DV can be carried out successfully in the presence of b-CD: the diffractogram of the IC formed by AP and b-CD in a 1:1 ratio (Figure 1 a) shows strong crystalline peaks and corresponds to a typical crystalline IC formed by b-CD and small guest molecules. It is different from the diffractograms of pure b-CD (Figure 1 b) and polymerized samples (Figure 1 c-f). Furthermore, in the 1 H NMR spectra of the polymerized samples the peaks at d = 6.3 and 7.0 ppm, assigned to the vinyl moiety, are no longer observed, which means that all of the vinyl groups have been transformed into dim...

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Section: Methodsmentioning

confidence: 99%

Controlling Polymer Architecture through Host–Guest Interactions

et al. 2005

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“…In this way, a polyrotaxane was formed by the action of light . Recently, a polymer-analogous Diels−Alder reaction of cyclopentadiene with the CD inclusion compound of a poly(maleate) was described as well 44 Stoppering of a pseudopolyrotaxane by photochemical [2+2] cycloaddition between the polymer and a co-included monomer …”

Section: 4 Statistical Stoppering Of Pseudopolyrotaxanes Along the Po...mentioning

confidence: 99%

“…266 Recently, a polymer-analogous Diels-Alder reaction of cyclopentadiene with the CD inclusion compound of a poly(maleate) was described as well. 267…”

Section: Statistical Stoppering Of Pseudopolyrotaxanes Along the Poly...mentioning

confidence: 99%