Ring Opening Polymerisation of Cyclic Carbonates With Organic Catalyst Systems
The present invention discloses a method for polymerising cyclic carbonates by immortal ring-opening polymerisation in the presence of organocatalysts and alcohol, said alcohol acting as initiator and as transfer agent.
1 . A process for polymerising five- or six- or seven-membered cyclic carbonates by immortal ring-opening polymerisation in the presence of organocatalyst precursors selected from amine, guanidine or phosphazene in the presence of alcohol acting both as co-initiator and transfer agent and wherein the molar ratio alcohol to catalyst ranges between 2 and 100.
2 . The process of claim 1 wherein the organocatalyst precursor is selected from 4-N,N-dimethylaminopyridine (DMAP) or 1,5,7-triazobicyclo-[4,4,0]dec-5-ene (TBD) or tert-butylimino-1,3dimethyl-perhydro-1,3,2diazaphosphine (BEMP).
3 . The process of claim 1 wherein the alcohol is selected from formula R′OH wherein R′ is an hydrocarbyl, linear or branched, saturated or unsaturated, having from 1 to 20 carbon atoms or is a poly-ol such as diol, triol or higher functionality polyhydridic alcohol.
4 . The process of claim 3 wherein R′ is a secondary alkyl residue or benzylic group, preferably PhCH 2 OH (BnOH).
5 . The process of claim 3 wherein the alcohol is a polyol selected from propanediol (PPD), or trimethylolpropane such as glycerol (GLY), or sugar-based alcohol such as erythritol or a cyclodextrine.
6 . The process of claim 3 wherein the cyclic carbonate is selected from trimethylene carbonate (TMC), 2-benzyloxy-trimethylene carbonate (BTMC), 2,2-dimethoxy-trimethylene carbonate (DMTMC), 2-hydroxy-trimethylene carbonate (TMCOH), 4-(benzyloxymethyl)-1,3-dioxolan-2-one (BDMC), 4-(hydroxymethyl)-1,3-dioxolan-2-one (DMCOH), 2-oxy-trimethylene carbonate (OTMC), and dehydrotrimethylene carbonate (DHTMC).
7 . The process of claim 6 wherein the cyclic carbonate is selected from TMC, BTMC or DMTMC.
8 . The process of claim 6 wherein the molar ratio alcohol to catalyst ranges between 3 and 50, preferably between 5 and 20.
9 . The process of claim 8 wherein the ratio monomer to alcohol ranges from 10 to 2500, preferably from 50 to 500.
10 . The process of claim 9 wherein the ratio monomer to catalyst ranges from 300 to 200000, preferably from 500 to 10000.
11 . The process of claim 10 wherein the polymerisation is carried out without solvent, preferably without chlorinated volatile solvent.
12 . Homo- or co-polymers of carbonates obtainable by the method of claim 1 .