Cationic cyclopolymerization of divinyl ethers with norbornane‐, norbornene‐, or adamantane‐containing substituents: Synthesis of cyclopoly(divinyl ether)s with bulky rigid side chains leading to high glass transition temperature

Abstract

Cationic cyclopolymerizations of 2,2‐bis(vinyloxymethyl)bicyclo[2.2.1]heptane (1), 5,5‐bis(vinyloxymethyl)‐2‐bicyclo[2.2.1]heptene (2), and 2,2‐bis(vinyloxymethyl)tricyclo[3.3.1.1]3, 7decane (3), divinyl ethers with a norbornane, norbornene, or adamantane unit, respectively, were investigated with the HCl/ZnCl2 initiating system in toluene and methylene chloride at −30 °C. All the reactions proceeded quantitatively to give gel‐free, soluble polymers in organic solvents. The number‐average molecular weight (Mn) of the polymers increased in direct proportion to monomer conversion and further increased on addition of a fresh monomer feed to the almost completely polymerized reaction mixture. The contents of the unreacted vinyl groups in the produced soluble polymers were less than ∼10 mol %, and therefore, the degree of cyclization of the polymers was determined to be over ∼90%. These facts show that cyclopolymerization of 1, 2, and 3 exclusively occurred and the poly(vinyl ether)s with the cyclized repeating units and polycyclic pendants were obtained with their molecular weights being regulated. BF3OEt2 initiator also caused cyclopolymerization of 1, 2, and 3 to give the corresponding high‐molecular‐weight cyclopolymers quantitatively. Glass transition temperatures (Tg's) of poly(1) and poly(2) were 165–180 °C, and Tg's of poly(3) were 211–231 °C; these values are very high as vinyl ether polymers. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2445–2454

Star-shaped cyclopolymers: A new category of star polymer with rigid cyclized arms prepared by controlled cationic cyclopolymerization and subsequent microgel formation of divinyl ethers

“…The broadening of polymer MWD in the course of cyclopolymerization of divinyl ethers comes from the occurrence of a minor extent of crosslinking and/or branching reactions to consume the pendant unreacted vinyl groups. 19,20,23,24 Figure 4 also shows the time-conversion plots (A), the M n (B), and M w /M n (C) of the product polymers vs. monomer conversion plots for the polymerization of 1 at 0 C. The polymerization proceeded smoothly and rather fast (conversion 5 100% at 10 min), and the M n s of the produced polymers increased in direct proportion to monomer conversion before and after the monomer addition with the polymer MWDs being narrow and were in good agreement with the calculated values assuming that one HCl molecule formed one polymer chain. The results of these plots in Figure 4 confirm living nature of the cyclopolymerization of 1 at 0 C. However, close inspection of the M n of the product polymers versus monomer conversion plots [ Fig.…”

“…28 Toluene was chosen as solvent, because the similar divinyl ether (divinyl ether with norbornene unit) underwent cyclopolymerization in this nonpolar solvent to give highly cyclized polymers with degree of cyclization being over 90%. 24 Figure 1 shows the MWD curves of the product polymers from 2. The reactions proceeded to attain nearly 94% conversion in 100 min at 230 C and 97% conversion in 10 min at 0 C. The M n s of the polymers increased with increasing conversion, and the polymer MWDs were unimodal and narrow with M w / M n < 1.2 throughout the polymerizations at both the temperatures.…”

“…In other words, the degree of cyclization for the poly(1) was over 97%, high value and similar to those of the reported cyclopolymers from other divinyl ethers. 19,20,23,24 To check living nature of the present cyclopolymerization systems, a fresh monomer feed (equivalent to the first stage) was added to the almost completely polymerized reaction mixture. The polymers obtained after the monomer addition were also soluble and the peak top of the MWD curves of the polymers clearly shifted toward high molecular weight region.…”

“…[21][22][23] Our recent study showed that some of cyclopoly(divinyl ether)s possessed high T g (up to 200 C) and high thermal decomposition temperature (up to 300 C). 24 The present study concerns the synthesis of star-shaped polymers consisting of cyclopoly(divinyl ether) arm chains and crosslinked poly(divinyl ether) microgel core by the combination of controlled cyclopolymerization and the subsequent crosslinking polymerization of divinyl ethers. The scheme 1 illustrates the reaction.…”

Synthesis, characterization, and properties of petroleum-based methacrylate polymers derived from tricyclodecane for microelectronics and optoelectronics applications

“…In bridged and non-polar polycyclic hydrocarbon structures, rigidity and three-dimensional size contribute to a high free volume, low moisture absorption and absence of π-electrons to lower the dielectric constant and increase optical transparency in the visible region [5][6][7][8][9][10][11][12][13]. Consequently, we hypothesized that incorporation of bulky, rigid tricycloalkyl substituents into PMMA would improve the thermal and mechanical properties of the polymer and maintain good optical and dielectric properties to result in high-performance, high-value materials for use in microelectronic and optoelectronic applications.…”