Alkylene carbonates

Empower Materials Inc. (2010) QPAC poly(alkylene carbonate) copolymers. http //www. empowermaterials.com Accessed 06 May 2011... 

Dixon DD, Ford ME, Mantell GJ (1980) Thermal stabilization of poly(alkylene carbonate)s. J Polym Sci, Part C Polym Lett 18 131-134... 

Esemplare P (2006) Stabilizing poly (alkylene carbonate) resins for coatings. US 2006-639600 20061215... 

Ree M-H, Hwang Y-T, Moon S-J, Kim M-H (2002) Copolymer comprising alkylene carbonate and method a preparing the same. Patent WO/2002/031023... 

Sant Angelo JG (1996) Substantially crystalline poly(alkylene carbonates) laminate and methods of making. US Patent 5,536,806... 

Two reports have appeared on the catalyzed reaction of C02 with epoxides to form alkylene carbonates. One of the processes uses phosphine complexes of zerovalent nickel as the catalyst (157), and appears closely related to the more recent isolation of (PCy3)2Ni(C02) (115). Ethylene oxide reacts in benzene under 500 psi pressure of C02 in a stainless steel autoclave at 100°C to form ethylene carbonate with 95% selectivity, (77), using as the catalysts NiL2, L = PCy3 or PPh3. 

The first reports describing the formation of cyclic carbonates (CCs) appeared during the early 1930s [99, 100], whilst the first patents (essentially related to the synthesis of ethene and propene carbonates) appeared more than 50 years ago [101, 102]. The Huntsman Corporation is one the world s largest producers of alkylene carbonates, with a capacity of 33 kt per year, covering approximately 50% of CC production worldwide. Today, CCs are widely used in the manufacture of... 

Alkylene carbonate may also react with a hydroxoalkylamine to create a cyclization reaction [260] that affords oxazolidinones (Scheme 7.17). 

The cyclic alkylene carbonates have also been applied as the cure-accelerators of phenol-formaldehyde (PF) [262-266] and sodium silicate [267] resin systems, which are widely used in foundry sand and wood binder applications. 

Six-membered alkylene carbonates have also been synthesized by reacting several 1,3-diols with a 15% excess of EC in the presence of titanium(IV) isopro-poxide at 293-323 K and 15-30mmHg [293], In this case, the high-purity (99%) alkylene carbonate was obtained via a short-path distillation at 323-373 K at reduced pressure. Alkylene carbonates have also been obtained by the disproportionation of l,3-bis(alkoxycarbonyloxy)propanes, using colloidal silica or Sn(II) stearate [294]. 

The transesterification of 1,2-diols by reaction with carbonates, both cyclic and linear, produces five-membered alkylene carbonates almost exclusively. A well-known example of this is the reaction of DMC with propene glycol to yield PC [295],... 

The coordination polymerisation of cyclic esters concerns mostly lactones, especially those containing a four-membered ring in the molecule. There is, however, an interest in the coordination polymerisation of such oxacyclic ester monomers as lactide and alkylene carbonate and, to a lesser extent, in the... 

It seems that the alkylene carbonate polymerisation proceeds via monomer decarboxylation in the first reaction step. The decarboxylation most probably involves metal carbonate species owing to ring opening of the 1,3-dioxolan-2-one via Cp—O bond cleavage [146,147]. A possible reaction scheme in the presence of zinc-based coordination catalysts is presented by scheme (14), in which, for the sake of clarity, participation of the adjacent zinc atom as the nucleophilic attack carrier is omitted ... 

Copolymerisation of propylene oxide as well as other oxiranes with carbon dioxide in the presence of zinc-based coordination catalysts is generally accompanied with the formation of a cyclic five-membered carbonate, propylene carbonate or another alkylene carbonate [147,206,207,210,212,230]. The alky-lene carbonate, however, is not the precursor for poly(alkylene carbonate), since it hardly undergoes a polymerisation under the given conditions [142-146],... 

Alkylene oxides and alkylene carbonates react with carbodiimides to give imidazolidine-... 

Tlie advantages of syntheses of alkylene carbonates, catalyzed by a iiansition metal, are demonstrated in numerous examples, for instance, Inc compounds such as combinations of zinc chloride and pyridine, catalyze the reaction to give more than a 90 . alkylene carbonate of high purity (219 222] -... 

Alkoxy-1,2,4,6,8-pentaazanaph thalenes, 431 Alkoxysulfonium fluoroborates, 78 a-Alkylacrylic adds, 301-302 N-Alkylanilines, 439 Alkylaiylacetylenes, 494 Alkylation of ketones, 30,64 2-Alkyl-1,3,2-benzodioxaboroles, 25 Alkylbenzohydroxamates, 389 OAlkylbenzohydroximoyl chlorides, 389 Alkylboronic add esters, 130 4-Alkyl-2-butene-l-ols, 53 2-Alkylcyclopentenones, 484 Alkyldichloroboranes, 130 2-r- Alkyl-1,3,2-dioxaborolanes, 69 Alkylene carbonates, 41 a-Alkylhydracrylic adds, 301-302 2-Alkylidenecydobutanols, 470 Alkylidene sulfones, 61 N-Alkylindoles, 246 Alkyl iodides, 336 Alkylmagnesium fluorides, 260... 

Therefore, any possible use of DMC as substitute of phosgene should be based on a different synthesis of DMC, not involving phosgene. Non-phosgene alternative routes for DMC production, basically, have relied on the reaction of methanol with carbon monoxide (oxidative carbonylation) or with carbon dioxide (direct carboxyl-ation with CO2, or indirect carboxylation, using urea or alkylene carbonates as CO2 carriers) (Figure 1.10) [72]. 

The production of the most prominent polycarbonate polymer based on bisphenoi A is the second largest consumer of phosgene, while poly(alkylene carbonates) are obtained from epoxides and C02. 

Starch carbonate diesters were formed by reaction of starch with alkylene carbonates under diminished pressure at 100-140 °C 2002 The products were proposed as surgical dusting powders. Another method involved dimethyl sulfoxide as the reaction medium, triethylamine as the catalyst, and trans-carbonates of glycosides as the acylating agents. Thionocarbonates were used similarly. The degree of substitution was O.4.2003 Another method involves 1-acyl I, I -carbodiirnidazole or dicarboxylic acid imidazolides at pH 8.O.2004... 

Another carbon dioxide insertion reaction is observed with Al (TPP)(OMe) This compound readily and reversibly traps carbon dioxide at room temperature in the presence of 1-methylimidazole. The trapped carbon dioxide is sufficiently activated to react with an epoxide at room temperature, thus producing the corresponding alkylcarbonate. As illustrated in Scheme 11, the cyclic carbonate is considered to be formed - at least partly - by nucleophilic attack on a linear intermediate. Thus the alkoxide aluminum porphyrin-methylimidazole system would be a good catalyst for synthesis of alkylene carbonates from carbon dioxide and epoxides under mild conditions. 

TABLE V Oxyalkylation of Pentaerythritols with Alkylene Carbonates or Alkylene Oxides ... 

---