Cyclic carbonate functional polymers

The monomers that have been explored most extensively are propylene carbonate methacrylate (PCMA) and propylene carbonate acrylate (PCA). These monomers are readily copolymerized with other commonly used unsaturated monomers to yield polymers with cyclic carbonate functionality. There are a few patents discussing the formation of coatings by the amine cross linking of these cyclocarbonate functional polymers. However, they do not appear commercially available. Thus, their use in the preparation of cyclic carbonate functional polymers has been limited. 

Webster, D. C., and Crain, A. L. Synthesis and Applications of Cyclic Carbonate Functional Polymers in Thermosetting Coatings, Progress in Organic Coatings (2000) 275-282. 

Cyclic carbonate functional polymers have been explored on a limited basis over a number of years. The cyclic carbonate group is an attractive functional group due to its reactivity with primary amines at ambient or slightly elevated temperatures to form crosslinked networks [7]. Cyclic carbonate functional polymers will also react with carboxylic acid functional polymers [2] at higher temperatures to form crosslinked coatings. 

Cyclic carbonate functional polymers have been prepared using several different routes. Bisphenol-A epoxy resins have been transformed into cyclic... 

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. 

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. 

Solution Copolymerizations. Our primary objective in this preliminary study was to gain a qualitative understanding of the copolymerization behavior of VEC with various types of unsaturated monomers. Particularly, we wanted to determine if VEC could be incorporated into a variety of polymer types of interest to the coatings industry. Since VEC is used to provide cyclic carbonate functionality for subsequent reaction or crosslinking, limited amounts of VEC are used in the copolymerizations. A semi-batch process was used in the copolymerization experiments to approach starved-feed conditions. Starved-feed conditions can result in copolymers with more uniform composition since the conversion is kept high in the reactor. While there are a large number of variables to consider, we elected to focus on monomer composition, polymerization temperature, and initiator level. 

VEC copolymerizes well with vinyl ester monomers over a range of compositions. To a more limited extent, VEC can also be incorporated into acrylic copolymers, however, we have not achieved quantitative incorporation. In the presence of styrene, essentially no VEC is incorporated into the copolymer. VEC can also be easily incorporated into a vinyl acetate/butyl acrylate latex, yielding a latex polymer containing cyclic carbonate functionality. The Tg of the copolymers can be modeled using extrapolated values for the Tg of a VEC homopolymer. 

More generally, the use of cyclic carbonate functional oligomers or polymers appears to be very promising in other numerous applications reported mainly in patents [23]. For example, PC can be used for the extraction of metals such as bismuth, cadmium, cerium, cobalt, copper, gold, iridium, iron, lead, mercury, molybdenum, palladium, rhodium, uranium, vanadium, and zinc. Due to its polarity, PC can also be used to make liquid... 

Takata and Endo, 1988]. A cyclic carbonate and cyclic ether are eliminated as by-products in reaction pathways a and b, respectively. Polymer LXXIV contains both ether and carbonate functional groups in the polymer chain. 

Various biodegradable polycarbonate(s) (PC) polymers have been fabricated via the organocatalytic ring-opening polymerisation of functional cyclic carbonate monomers, which were quarternised to create cationic polymers with various pendent structures such as alkyl, aromatic and imidazolinium (Figure 8.4). These polymers have shown excellent antimicrobial properties and haemolytic characteristics when assayed using rat red blood cells [98]. 

One of the most widely used methods for the synthesis of cyclic polymers of controlled size and narrow dispersity is based on the end-to-end chain coupling of a,co-difunctional linear polymer precursors in highly dilute reaction conditions. This method offers a series of significant advantages it may be used both for polymers with in-chain reactive functions and for systems having no functional groups in their backbone such as saturated carbon-carbon bond polymers. The absence of potentially... 

An alternative way to mne the polymer properties and insert desired functionalities is copolymerization with different monomers. Cyclic carbonates have been copolymerized with various other cyclic monomers, such as lactones or lactides. For example, TMC was copolymerized with 5-methyl-5-benzyloxycar-bonyl-l,3-dioxan-2-one (MBC) using lipase from Pseudomonas flourescens (PF) resulting in a highly amorphous random copolymers (Fig. 8) [74]. In another smdy, 5-benzyloxy-trimethylene carbonate (BTMC) was copolymerized with 5,5-dimethyl-trimethylene carbonate (DTC) using an immobilized hpase on silica particles [79]. In the copolymerization of TMC with a lactone, m-pentadecalactone (PDL), employing Novozyme 435, highly erystalline TMC-PDL eopolymers were obtained, and as opposed to chemical catalysts, enzyme eatalyst (Novozyme 435) polymerized PDL more rapidly than TMC [80]. 

Random polymers are the statistical arrangement of comonomer in their backbone. Numerous monomers have been used to copolymerize with LA, such as lactones, cyclic carbonates, hydroxyl acid, amino acid, and so on, to improve the flexibility, thermal stability, degradability, biocompatibility, hydrophilicity, functionality, etc. The most widely used technique to synthesize random copolymers of PLA is controlled/ living ring-opening polymerization. 

Around 110 megatons (Mt) of CO2 are annually used in commercial synthesis processes, to produce urea, salicylic acid, cyclic carbonates, and polycarbonates. The largest use is for urea production, which reached around 90 Mt/yr in 1997. In addition to these applications, there are a number of promising reactions currently under study in various laboratories, reactions that differ in the extent to which CO2 is reduced during the chemical transformation. They include the synthesis of commodities and intermediates (acetic acid, methanol, carbonates, cyclic carbonates, and lactones), polymers (polyurethanes, polypyrones) and a variety of functionalized carboxylic acids (propenic acid, 3-hexen-l,6-dioic acid). A more detailed description can be found in the cited review. ... 

The use of carbon dioxide in the synthesis of functional molecules is of considerable interest. An example is the industrially important reaction of epoxides with carbon dioxide to give cyclic carbonates. Also, functionalization of acetylenes and dienes with carbon dioxide on transition metal catalysts gives rise to the formation of cyclic lactones or dicarboxylic acids. The activation of carbon dioxide by metal complexes was reviewed in 1983 . Reactions of carbon dioxide with carbon-carbon bond formation catalyzed by transition metal complexes was reviewed in 1988 ", heterogenous catalytic reactions of carbon dioxide were reviewed in 1995, and the use of carbon dioxide as comonomers for functional polymers was reviewed in 2005. ... 

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