1.3- Dioxolane copolymerization with

THF readily copolymerizes with cyclic formals also (25, 104). Okada et al. (104) have determined reactivity ratios for copolymerization of THF with 1,3-dioxolane using BFg-etherate catalyst at 0°C. The values found are (THF) = 28 4, and r2 (dioxolane) = 0.25 0.05. 

Certain cyclic ethers which will not homopolymerize will copolymerize with THF (25, 52). These cyclic ethers are stable five and six-membered ring compounds such as 2-methyltetrahydrofuran (2-MeTHF), and 1,4-dioxane (DOX). It is probable that 4-phenyl-l,3-dioxane (PhDOX), tetrahydropyran (THP), and 4-methyl-l,3-dioxolane (MDOL) which do not homopolymerize but which have been reported to copolymerize with BCMO (107, 108) would also copolymerize with THF. In the copolymerizations a correlation was again found between the basicity of the attacking ether and its reactivity with the cyclic oxonium ion. The... 

The difference in formaldehyde equilibrium concentration between homogeneous and heterogeneous polymerization is large enough to indicate a difference in the physical state of cationic chain ends in the dissolved and in the crystalline polymer. Thus, Model B is ruled out. In the homopolymerization of trioxane and in the heterogeneous copolymerization with small amounts of dioxolane the active centers of chains which have precipitated from the solution predominantly are directly on the crystal surface (Model A). According to Wunderlich (20, 21), this is the first case in addition polymerization where Model A—simultaneous polymerization and crystallization—has been proved experimentally. 

The process based on cationic polymerization of 1,3,5-trioxane employs a different principle for stabilization of polymer. Trioxane is copolymerized with a few percent of 1,3-dioxolane (or ethylene oxide). The sequence of —OCH2— units is then separated from time to time by —OCH2CH2— units. The product of copolymerization is subsequently heated to eliminate the terminal units (unstable fraction). Depropagation proceeds until the stable —CH2CH2OH group is reached ... 

Some heterocyclic monomers may undergo random copolymerization with vinyl monomers. This is a case of cyclic acetals (e.g., 1,3-dioxolane) which forms the random copolymers with styrene [308,309] or isoprene [310], Apparently, the oxycarbenium ions, being in equilibrium with tertiary oxonium ions (cf., Section II.B.6.b), are reactive enough to add styrene ... 

The process of formaldehyde copolymerization with dioxolane is characterized by the formation of a number of by-products with a dynamic equilibrium established among them60. To the previously found trioxepane and trioxane was later added a soluble copolymer whose composition is similar to that of polytrioxepane58 (Fig. 9). 

Polymers with pendant cyclic carbonate functionality were synthesized via the free radical copolymerization of vinyl ethylene carbonate (4-ethenyl-l,3-dioxolane-2-one, VEC) with other imsaturated monomers. Both solution and emulsion free radical processes were used. In solution copolymerizations, it was found that VEC copolymerizes completely with vinyl ester monomers over a wide compositional range. Conversions of monomer to polymer are quantitative with complete incorporation of VEC into the copolymers. Cyclic carbonate functional latex polymers were prepared by the emulsion copolymerization of VEC with vinyl acetate and butyl acrylate. VEC incorporation was quantitative and did not affect the stability of the latex. When copolymerized with acrylic monomers, however, VEC is not completely incorporated into the copolymer. Sufficient levels can be incorporated to provide adequate cyclic carbonate functionality for subsequent reaction and crosslinking. The unincorporated VEC can be removed using a thin film evaporator. The Tg of VEC copolymers can be modeled over the compositional range studied using either linear or Fox models with extrapolated values of the Tg of VEC homopolymer. 

Limited information exists in the literature, however, on the homo- or copolymerization of vinyl ethylene carbonate, 1 (VEC or 4-ethenyl-l,3-dioxolane-2-one) for the preparation of cyclic carbonate functional polymers. A few comments regarding polymerization of VEC are given in an early patent [9], In the only reported study of the copolymerization behavior of VEC, Asahara, Seno, and Imai described the copolymerization of VEC with vinyl acetate, styrene, and maleic anhydride and determined reactivity ratios [10. Their results indicated that VEC would copolymerize well with vinyl acetate, but in copolymerizations with styrene, little VEC could be incorporated into the copolymer. VEC appeared to copolymerize with maleic anhydride, however the compositions of the copolymers was not reported. Our goal was to further explore the use of VEC in the synthesis of cyclic carbonate functional polymers. 

If formaldehyde is copolymerized with a second monomer, which is a cyclic either such as ethylene oxide and 1,3-dioxolane, end-group capping is not necessary. The copolymerization results in occasional incorporation of molecules containing two successive methylene groups, whereby the tendency of the molecules to unzip is markedly reduced. This principle is made use of in the commercial products marketed as Celcon (Celanese), Hostaform (Farbwerke Hoechst), and Duracon (Polyplastic). 

For TOX copolymerization with ethylene oxide (EO), EO was first converted to low molecular weight copolymer and cyclic oligomers such as dioxolane (DOL) and 1,3,5-trioxepane (TOP) (4). For either EO and DOL as comonomer with TOX, they were found to be preferentially incorporated during the induction period (5). 

In addition to the above, liquid copolymers form from 1,3-dioxolane with ethylene oxide, when boron trifluoride is used as the catalyst. Also, a rubbery copolymer forms from tetrahydrofuran and 3,3-diethoxycyclobutane with phosphorus pentafluoride catalyst. A3,3-bis(chloromethyl) oxacy-clobutane copolymerizes with tetrahydrofuran with boron fluoride or with ferric chloride catalysis. The product is also a rubbery material. ... 

Various copolymers were reported from trioxane with dioxolane or with glycidyl ethers. Fcff instance, a copolymer of trioxane and dioxolane forms with SnCU, BF3, or Ha04 catalysts. The products from each reaction differ in molecular weights and in molecular weight distributions. Copolymerizations of trioxane with phenylglycidyl ether yield random copolymers. 

Perfluoro-2-inethylene-l,3-dioxolane monomers copolymerizes with various commercially available fluorovinyl monomers, too. Perfluoro-3-methylene-2,4-dioxabicyclo [3,3,0] octane (Figure 16.5F) was copolymerized with chlorotrifluo-roethylene (CTFE), perfluoropropyl vinyl ether, perfluoromethyl vinyl ether, and vinylidene fluoride [23] by a free radical initiator such as perfluorodibenzoylperox-ide or tert-butyl peroxypivalate in bulk or in solution, respectively (see Figure 16.9). 

Perfluoro-2-methylene-l,3-dioxolane monomers can be copolymerized with each other to modify the physical properties of the polymers. The refractive index and Tg depend on the copolymer composition. The copolymers are readily prepared in solution and in bulk. For example, the copolymerization reactivity ratios of monomers A and C (Figure 4.10) are = 0.97 and - 0.85 [35]. The data show that this copolymerization yields nearly ideal random copolymers. Figure 4.11 shows the change in Tg as a function of the copolymer composition. The copolymers have only one T, which increases from 110 to 165 C as the mole fraction of monomer A increases. The copolymer films prepared by casting are flexible and tough and have a high optical transparency. 

According to Astle (4o) et al. trioxocane can be obtained by condensation of diethylene glycol with paraformaldehyde it is easily polymerizable by cationic catalysts or by electrochemical initiation (41). Copolymerization with e.g. trioxane or dioxolane are possible, too (41). Kinetics, thermodynamics and mechanism of homopolymerization have been studied in detail by several authors. According to the analytic results of Weichert (42) the structure of the polymers of /2/... 

The monomers 4-methyl-l,3-dioxene-4 and 2-trichloromethyl-4-methylene-l,3-dioxolane and other 4-methylene-l,3-dioxolanes are known to also undergo spontaneous copolymerization, with MA at temperatures >50 C, giving good yields of low-molecular-weight, alternating copolymer. The equimolar 4-methyl-l,3-dioxene-4-MA copolymer structure 11 is shown below. 

For the sake of visualizing the dependence of the ceiling temperature on the composition of the copolymerization system, the author performed, especially for this chapter, some simulations and the computed ceiling temperatures for the copolymerization of 1,3-dioxolane (DXL) with 1,3-dioxane are presented in Figure 3 (see Section 4.05.6.1.2). 

Vinyl-functional alkylene carbonates can also be prepared from the corresponding epoxides in a manner similar to the commercial manufacture of ethylene and PCs via CO2 insertion. The most notable examples of this technology are the syntheses of 4-vinyl-1,3-dioxolan-2-one (vinyl ethylene carbonate, VEC) (5, Scheme 24) from 3,4-epoxy-1-butene or 4-phenyl-5-vinyl-l,3-dioxolan-2-one (6, Scheme 24) from analogous aromatic derivative l-phenyl-2-vinyl oxirane. Although the homopolymerization of both vinyl monomers produced polymers in relatively low yield, copolymerizations effectively provided cyclic carbonate-containing copolymers. It was found that VEC can be copolymerized with readily available vinyl monomers, such as styrene, alkyl acrylates and methacrylates, and vinyl esters.With the exception of styrene, the authors found that VEC will undergo free-radical solution or emulsion copolymerization to produce polymeric species with a pendant five-membered alkylene carbonate functionality that can be further cross-linked by reaction with amines. Polymerizations of 4-phenyl-5-vinyl-l,3-dioxolan-2-one also provided cyclic carbonate-containing copolymers. 

There has been a report on the synthesis and utilization of an cvo-methylene dioxolane bearing styryl group (Scheme 28). The styryl group can be used for the copolymerization with other... 

Copolymers of the Teflon AF series are prepared in four steps starting with hexafluoro-acetone (HFA) and ethylene oxide (EO). Condensation reactions of HFA and EO result in 2,2-bis-trifluoromethyl-l,3-dioxolane, which is successively chlorinated, fluorinated, and dechlorinated to give the 2,2-bis-trifluoromethyl-4,5-difluoro-l,3-dioxole (TFMDFD) monomer (Hung, 1993 Resnick, 1976). This monomer copolymerizes with tetrafluoro-ethylene (TFE). The physical properties of these amorphous copolymers vary according to the relative amoimts of the co-monomers, TFMDFD and TFE. Currently, DuPont is producing two commercial grades, AF-1600 and AF-2400. Teflon AF-2400 and AF-1600 are the names of copolymers for which n = 0.87 and 0.65, respectively, where n is the percentage of the TFMDFD monomer (see Fig. 24.9). Table 24.4 summarizes physical properties of the two fluoropolymers. 

In our previous work [8], we rqjorted the synthesis of (2-oxo-l,3-dioxolan-4-yl)methacrylate (DOMA) finrn carbon dioxide and glycidyl methacrylate (GMA) using quaternary salt catalysts. In the present work, we studied the catalytic pra rmance of alkyhnethyl imidazolium salt ionic liquid in the synthesis of polycarbonate from the copolyraerization of CO2 with GMA. The influences of copolymerization variable like catalyst structure and reaction tenperature on the conversion of GMA and the yield of the polycarbonate have been discussed. 

Polyoxymethylene, also referred to as acetal resin or POM, is obtained either by anionic polymerization of formaldehyde or cationic ring-opening copolymerization of trioxane with a small amount of a cyclic ether or acetal (e.g., ethylene oxide or 1,3-dioxolane) [Cherdron et al., 1988 Dolce and Grates, 1985 Yamasaki et al., 2001]. The properties and uses of POM have been discussed in Sec. 5-6d. 

Cationic Copolymerization of 1,3>5-Trioxane with 1,3-Dioxolane (Ring-Opening Copolymerization)... 

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