Synthesis and polymerization of vinylcyclopropanes

Abstract

SUMMARY: Vinylcyclopropanes are important synthetic intermediates in organic chemistry and are mostly synthesized by the simultaneous introduction of the cyclopropane and the vinyl unit, e. g., by the reaction of trans-1,4-dihalobutenes with b -dicarbonyl compounds or the addition of carbenes to dienes. The polymerization of vinylcyclopropane itself results in vinyl polymers with predominantly 1,2-structural units. The radical polymerization of substituted vinylcyclopropanes results in polymers with mainly 1,5-ring-opened units, whereby radical stabilizing substituents or electron-withdrawing groups increase the radical polymerizability and the ring-opening ability. The vinylcyclopropanes undergo a radical copolymerization with other vinyl monomers, such as methacrylates, and, in comparison to the polymerization of these linear vinyl monomers, the vinylcyclopropanes show a significantly lower volume shrinkage during ring-opening polymerization. Hybrid vinylcyclopropanes are polymerized step-by-step under formation of reactive polymers or polymer networks. Multifunctional cross-linking vinylcyclopropanes can be used as new low-shrinking matrix monomers for photopolymerizable materials. In addition, the sol-gel process of trialkoxysilyl-functionalized vinylcyclopropanes affords low shrinking organic-inorganic nanocomposites.

Ring-Opening Polymerization—An Introductory Review

“…Vinyl cyclopropane and its derivatives have been studied by several groups [8][9][10][11]. The three membered ring has considerable ring strain (115 kJ mol −1 ) [2] and the simple RROP thus competes with the vinyl chain polymerization (see Figure 2).…”

New Architecture of Liquid-Crystalline Polymers from Fluorinated Vinylcyclopropanes

“…Among the various cyclic monomers, vinylcyclopropanes [2] are of interest because they easily polymerize by a free-radical ring-opening mechanism due to the release of the cyclopropane-ring strain. [3 -5] Furthermore, the presence of bulky substituents on the ring can limit the increase in conformational freedom during polymerization, thereby resulting in a reduced contraction of free volume.…”

Monomers for Adhesive Polymers, 3. Synthesis, Radical Polymerization and Adhesive Properties of Hydrolytically Stable Phosphonic Acid Monomers

“…Methacrylonitrilo-or N,N-diethylmethacrylamido-phosphonic acids were obtained by ether formation of a-chloromethacrylonitrile with hydroxyalkyl phosphonates or aminolysis of 2-[4-(dimethoxyphosphoryl)-2-oxabutyl]acrylic acid and subsequent hydrolysis to produce the corresponding phosphonic acid. The structure of the new monomers was characterized by IR and by 1 H, 13 C and 31 P NMR spectroscopy. The monomers dissolve well in water and are hydrolytically stable.…”

“…In this respect, we synthesized a new class of phosphonic acid a-methylsubstituted acrylates, for example, ethyl 2-[4-(dihydroxyphosphoryl)-2-oxa-butyl]acrylate (1), in which the polymerizable acrylate group is connected to the strong acidic phosphonic acid group via a hydrolytically stable ether bond. Therefore this phosphonic acid acrylate shows an enhanced hydrolytic stability and can be used as an adhesive monomer in dentine adhesives.…”

“…(DMPOBA) were prepared as previously described. [1] Unless stated otherwise, all reagents were purchased from Fluka. The water soluble AMPAHC was used without further purification.…”