Carbohydrate/Monomer Complexes in Aqueous Polymerizations:  Methylated-β-cyclodextrin Mediated Aqueous Polymerization of Hydrophobic Methacrylic Monomers

Abstract

Hydrophobic methacrylic monomers were polymerized in aqueous media using methylated (1.8)-beta-cyclodextrin (MeCD) additives. Hydrophobic monomers tert-butyl methacrylate (tBuMA), cyclohexyl methacrylate (CMA), and 2-ethylhexyl methacrylate (2EHMA) were each dissolved in chloroform with MeCD. Chloroform was then evaporated to yield solid monomer/cyclodextrin complexes. Complexes were shown by 1H NMR and thermogravimetric analysis (TGA) to have molar ratios of monomer to MeCD as high as 0.72/1.00. The water-soluble complexes were readily polymerized in aqueous media using free radical initiation. During polymerization, hydrophobic methacrylic polymers precipitated and the majority of MeCD remained in solution. Poly(alkyl methacrylates) synthesized via this method exhibited number-average molecular weights ranging from 50,000 to 150,000 with polydispersities from 3.2 to 5.5 depending on monomer structure, and isolated yields were as high as 86%. Additionally, corresponding methacrylic/carbohydrate films were prepared and examined. High molecular weight poly(tBuMA), poly(CMA), and poly(2EHMA) were blended with MeCD to produce optically clear films with as high as 20 wt % MeCD. Differential scanning calorimetry (DSC) characterization indicated that the glass transition temperatures of these novel carbohydrate blends were controllable over a 20 degrees C range depending on the relative concentration of each component.

Characterization of silk fibroin based films loaded with rutin–β-cyclodextrin inclusion complexes

“…CDs are cyclic molecules composed of glucopyranose ring units to form truncated cone type, doughnut structures. The exterior of the CDs are hydrophilic while the interior is hydrophobic, and the different CDs possess different cavity sizes according to the number of glucopyranose rings present [8]. This structure provides CDs to form complex compounds with the molecules having ability to locate the cavity.…”

“…CDs have been found to be safe enough to be used in food and drug systems. Therefore, cyclodextrins and their derivatives have found a place in a number of consumer products and in many industrial processes [8]. Usage of CD in drug formulations enhance solubility [18].…”

Host/guest complex of Me-β-CD/2,2-dimethoxy-2-phenyl acetophenone for initiation of aqueous photopolymerization: Kinetics and mechanism

“…Due to the special molecular structure they are able to enclose smaller hydrophobic molecules or hydrophobic side groups of polymer as guests into their cavities to form host/guest compounds in aqueous and in emulsion [4][5][6][7][8][9][10]. This inclusion complex leads to a significant change of the solution properties and reactivities of the guest molecule, but without any chemical modification [11][12][13][14][15][16][17]. And it also attracted more and more attention in recent years because of their potential to serve as molecular devices and molecular machines, as well as nanostructured functional materials, such as cyclodextrin-based light-driven molecular shuttle [18,19] and rotaxane-encapsulated dyes to prevent the chromophore degradation [20].…”

Towards Green Routes for Polymer Synthesis: Polymerization of Cyclodextrin Host‐Guest Complexed Diethyl Fumarate and Copolymerization with Complexed Styrene in Homogenous Aqueous Solution

“…Recently, Rimmer and Tattersall, [18] and Madison and Long, [19] have reported the emulsion polymerization of some (meth)acrylates in the presence of CDs.…”